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Anonymous Posted on Aug 12, 2011

I have a 1991 Yamaha Waverunner III, WRA650P with weak or no spark. Starting at the very beginning: Down at the crankshaft, the stator, coil, whatever it is called, that generates the electricity to begin with - I have 5 wires coming out of that - 2 green, 1 black, 1 Red/White stripe, 1 Brown/White stripe. All 5 wires first go into the CDI/electrical box. The black goes to a common ground in there, the Brown/White stripe and Red/White stripe go directly into the CDI unit. At this point I am not sure if the person that replaced the CDI/electrical box before me wired everything correctly. It appears that for the 2 green wires, 1 goes directly to the rectifier, and the other splits and goes both to the rectifier and up to the handlebars. Does it matter which green is plugged into which? The connectors are both the same so I don't know which goes directly to the rectifier & which goes to the split - does it matter? Anyway.... I have new plugs and new plug caps. The entire electrical box unit was replaced but I still suspect it...? So what is the first test I should do to see if my stator is good and I am getting electricity generated? I have a digital multimeter with a DVA. Already Tried: New spark plugs, new plug caps, good battery. It IS getting fuel, compression is good. No spark. Actually once in awhile I see a very faint spark going from the outer edge of the spark plug to what I am grounding it against, but not in the gap. So basically no spark. Also tested: The black wire from the magneto (unplugged) to the negative battery terminal is pretty much a dead short. The Red/White to black is 14 ohms resistance. The Brown/White to black is somewhat confusing - it starts out at around 275.... and slowly climbs. I wait 10 seconds and retest and it will be 2 or 3 higher.... if I walk away for several minutes it will be 100 higher..... I came upstairs & watched 15 min of TV and went back down and it was over 600. I plugged the wires back in, hit the starter and turned it over a couple of times, unplugged them and retested, and it was back down around 275 again..... and slowly starting to climb. I've read where checking resistance on the stator can be iffy, and more accurate is the cranking voltage. What should that read?

  • 37 more comments 
  • Anonymous Aug 24, 2011

    jturcotte wrote,
    Hi, have you checked continuity through the kill switch on the handlebar? I don't have the wiring diagram, so not sure which color the wires are. You mention one of the green wires goes up to the handlebars, but which one comes back? Or, if none comes back, then the switch probably just grounds that wire when you flip it off. If that's the case, is the wire grounded regardless of the position of the switch?
    If the kill switch is OK, I would try reversing the polarity out of the magneto.



    The green wire goes to the fuel gauge. It appears the white & black (ground) wire go to the kill switch on the handlebar. I took it apart to make sure the kill button was disengaged and put the continuity tester on the white wire to ground. It is open, and when I press the kill switch, or the safety switch, it grounds. So it appears the switch is ok.

    How do I reverse the polarity of the magneto? Which wires do I switch?

    jturcotte wrote,
    Hi, have you checked continuity through the kill switch on the handlebar? I don't have the wiring diagram, so not sure which color the wires are. You mention one of the green wires goes up to the handlebars, but which one comes back? Or, if none comes back, then the switch probably just grounds that wire when you flip it off. If that's the case, is the wire grounded regardless of the position of the switch?
    If the kill switch is OK, I would try reversing the polarity out of the magneto.

    The green wire goes to the fuel gauge. It appears the white & black (ground) wire go to the kill switch on the handlebar. I took it apart to make sure the kill button was disengaged and put the continuity tester on the white wire to ground. It is open, and when I press the kill switch, or the safety switch, it grounds. So it appears the switch is ok.
    How do I reverse the polarity of the magneto? Which wires do I switch?

  • Anonymous Aug 24, 2011

    I actually have a Service Manual with the wiring diagram but I'm afraid I don't know how to read it very well - lol. Anyway, as near as I can tell, it is the brown/white and red/white wires? So I unplugged them (the battery is fine, spins the motor over fast no problem) - and still no spark. I switched those 2 wires and still no spark. As near as I can tell everything appears to be wired correctly, everything is color-coded, and the kill switch on the handlebar is fine, (I actually unplugged it completely from the circuit to test). What I'd really like to do is trace/test each component from the beginning to determine where the problem is. I'd hate to spend the $$ for a new CDI unit if that wasn't the problem, as it already has had 2 complete electrical boxes and all their components put in it. The person I bought it from bought a box & replaced but still couldn't get a spark, but we don't know for sure the box he bought was ok (it was not new) - so I would like to test each part starting at the beginning to determine what is bad.

  • Anonymous Aug 24, 2011

    I'm sorry but you'll have to be a little more specific when you mention "the coil". The diagram shows a lighting coil, and ignition coil, etc...... which coil and which wires specifically? I apologize but I'm afraid you'll have to be very specific when you mention what and how to test, thx.

  • Anonymous Aug 25, 2011

    With the ignition coil completely unplugged, the small wires coming into it measure between 2 and 3 ohms, and the large wires going out to the spark plugs measure about 4.2K. According to the service manual I have, they should be .092 and 4.1K +/- 15%, respectively, (at quite a bit cooler temp than it currently is in my garage, though - lol). Are these measurements ok? The old ignition coil that came out of it measures exactly the same, by the way. I also have a DVA with my digital multimeter, if there is anything I need to test with that.

  • Anonymous Aug 26, 2011

    The fuse is good, first thing I checked. Remember, it does occasionally get a very weak spark at the plug, but usually around the edges to whatever part of the motor I'm grounding it to, never across the gap - and only occasionally at that. Once again I apologize, but you'll need to be specific - do you mean test with the DVA plugged in? I assume you are talking about testing the wires coming into the ignition coil?

  • Anonymous Aug 26, 2011

    Trying to navigate this new website.... not helpful.
    The fuse is fine. Do you mean to use the DVA and check the wires coming into the ignition coil?

  • Anonymous Aug 27, 2011

    You didn't mention if I should test the voltage with the DVA so I did not use it. Anway, the voltage to the ignition coil tested about 11 volts. This was with the ignition coil unplugged - should it be tested with the ignition coil plugged in or does it matter? According to the manual, the pulsar coil was the white/red wire - testing it to the black measured 14 ohms, exactly what the manual said it should I also tested the lighting coil resistanc (1.1 - manual said .9) and the charge coil resistance (228 - manual said 365). Earlier you mentioned that this model ran off the battery, so if that is the case, if I'm not getting spark, does it matter what is coming out of the magneto? Forgive my ignorance, just asking for my own understanding. I realize this is what will charge the battery & so on but I didn't realize it should be able to run from the battery alone, if I understood you correctly. Anyway, assuming everything is ok so far (including your thoughts on whether or not the lighting coil is ok and would/could be the cause of my weak/no spark) what is the next step? Thx.

  • Anonymous Aug 28, 2011

    That was the AC voltage with the engine cranking. Digital voltmeter set on VAC, 200. 11 Volts without the ignition coil connected. When I connected the ignition coil, I got nothing. I switched it over to AAC, 200m, and it read 3.2 with the coil connected, 5.6 without it connected when cranking. This was without the DVA adaptor.

  • Anonymous Aug 28, 2011

    No, I have not switched th wires on the ignition coil. They are color coded - orange connects to orange, and black to black - and the plugs on the ends are opposite so they will only plug into the correct wire. I could try to rig up a jump wire and try it. And the plugs are brand new. The "spark" I see is very rare and intermittent - when I turn off the lights in the garage and crank it over in total darkness, holding the plug against the block or something to ground it, I very occasionally see a tiny blue spark there - very weak, and never in the plug gap. It could be something else grounding out thru the plug, I don't know. I"m not sure how to adjust the voltmeter, not sure I know what the AAC 200m means, but when I put it on that setting the voltage didn't change that much, from 3.2 to 5.6 approx......

  • Anonymous Aug 28, 2011

    The black connects to the box with other black wires with a big screw - a common ground, I presume - and the orange wire disappears into the CDI unit.

  • Anonymous Aug 28, 2011

    I have the entire electrical box unattached from the side of the jetski and open, just lying there - it doesn't need to be attached to the frame or anything for grounding purposes, does it? Of course, I only got the rare intermittent spark just the same even when it was..... just making sure....

  • Anonymous Aug 28, 2011

    I don't see any of the black wires going to the frame anywhere. As a matter of fact, the big electrical box that houses everything just bolts to the plastic or fiberglass inside of the ski, I don't see anything anywhere that would act as a ground. But, again, the behavior (weak/no spark) is the exact same whether the box is attached to the side or not. Just as a test, I jumped a wire from the common ground spot in the box to the frame somewhere and there was no difference. I also hooked up the old ignition coil and got the same cranking readings as above (no VAC when connected).
    No apologies necessary, I'm mystified as well. I have not had the starter gear off the crankshaft - whatever that means. I've only had the electrical box apart. But that raises my question again - if this thing is supposed to be able to run completely off of the battery alone, (and the battery is new and fully charged - turns it over no problem) - then even if there was something defective inside where the pulsar coil is, why would that matter? if I am supposed to be able to run this with the wires from the pulsar coil disconnected, then wouldn't my first problem lie elsewhere? Unless maybe something there was shorted out..... should I do all these tests with the wires from the crankshaft disconnected? Looks like a bit of a job to take all that off the end of the crankshaft, is there anything else to test in the electrical box before I go down that path?

  • Anonymous Aug 28, 2011

    Ok, I'll get started on that then, but I'm still a little confused at this point and maybe you could explain it to me - if this is supposed to be able to run off the battery alone - and earlier, you had me disconnect/take the magneto out of the circuit entirely - then the fact that I'm still not getting spark running straight off the battery would say that the problem lies elsewhere, wouldn't it? I apologize, I don't understand the electrical system that well but that seems to follow from what you've told me so far. Also, I had seen elsewhere where you needed a DVA to use a digital voltmeter like mine to test voltage while cranking coming straight off the magneto, (so I got one) but never could find for certain what I should be getting for readings when doing that. Would that be a way to test the magneto without disassembling it?

  • Anonymous Aug 28, 2011

    at this point I'm just about ready to bite the bullet and spring the $$ for a new CDI unit. I tried testing it based on the specs in the service manual and it seems nothing tests anywhere near what it should, but I"m not sure I read the diagram correctly - I profess my ignorance when it comes to electronics & schematics. Could you possibly give me just a few tests for the CDI unit, being very specific? Such as, I assume it is with all the CDI unit wires disconnected from everything - and which voltmeter lead to put on which wire (negative/black or positive/red lead) to which CDI wire and what readings I should see? Thx.

  • Anonymous Aug 28, 2011

    This explanation I cut/pasted from elsewhere: "DVA means direct voltage adapter. It's just another name for a peak reading voltmeter...... It's different from a standard voltmeter in that it's designed to read voltages that are not constant. It reads the peak or highest voltages from a source that gives a voltage that rises and falls. For OMC and other brands of conventional 2 strokes it's required equipment in service manuals for testing ignition components."
    Thanks for the explanation on why the magneto is still needed. The replacement electronics box was bought on E-Bay by someone else, that was supposedly fine, but I/we still have our misgivings about that. Anyway, I'll work on getting inside to look at the magneto as you've described. It might be a little longer before I can reply back but I will as soon as I can.

  • Anonymous Aug 28, 2011

    I have the CDR all disconnected. My problem is that it gives different readings depending on whether you switch the test leads around, and it is not clear at all from the chart which is which. I"ve been trying to figure out how to paste a pic of it here like you did above?

  • Anonymous Aug 28, 2011

    I hooked up the DVA to the pulsar coil wires, with the voltmeter set on DC. I don't really see any "blips", I get a peak reading that pretty much levels out after a few revolutions. I get about 7-8volts, whether the red/white wire (pulsar wire) is plugged in or unplugged and reading straight from the coil. (I noticed if I unplug the sparkplug wires, the reading goes down to about 4).

  • Anonymous Aug 28, 2011

    Here is the pic from the service manual



  • Anonymous Aug 28, 2011

    I managed to get the CDI diagram attached & sent, thx.

  • Anonymous Aug 29, 2011

    With it set on VAC, I get nothing, moved it over to AAC, with the switch set on 200m, I get about 90 thru the DVA.
    Regarding the CDI - ok thx, this is why I was confused, it seems as if the readings are actually closer to what they should be when I switch the wires.... ok, it is a brand-new digital voltmeter, I have the black lead plugged into the common ground and the red to the red (inputs are color-coded). But it is still strange. Example, just with the black test lead on the black wire, I get this when connecting red test lead to: W(infinity), should be 20). O - infinity. W/R - with the meter switch set on 200K, I get 55, with it set on 2000K, I get 280 (should be 300). P - infinity (should be 7). Br/W, 62 (should be 4). But if I switch the test leads, I get 122 for W, 12 for P, and 7 for Br/W.
    Jumping down to neg/black test lead on W/R: B=783, everything else infinity except Br/W=970. Neg on Br/W, B = 134/38 (switch on 2000K/200K), P spikes then goes to infinity, W/R = 450/131 on 2000k/200k. Everything else infinity. Looks like the readings are all over the place, so I/m guessing my CDI is bad? I also ran a few tests on the old CDI - some of the measurements on it were actually closer to spec than this one, but many were still bad - as in reading infinity when I should have gotten something......
    So the final question is: Is there something else, like in the magneto, that could have made the new CDI go bad, or did the person that bought it just take their chances getting a good one buying on E-Bay? ;-) I also have a 1988 Yamaha 500 Waverunner that runs good, could I swap the CDI into this one to test? Would that one be compatible?

  • Anonymous Aug 29, 2011

    Thank you so much for having so much patience with me with this. It will be next weekend before I can get to the 500 but I will see if it is compatible and if so try it out and see before I order a CDI (expensive!).
    I also have another yamaha waverunner with a different problem (got a couple of fixer-uppers) - can I start a new thread with you on that one?

  • Anonymous Aug 31, 2011

    Well, I took the CDI unit out of a 2001 Yamah XL700Z that runs, according to the exploded diagrams the 650 is 6M6-85540-01-00, the 700 is 6K8-85540-01-00. It had the same wires except a couple of them the male/female was reversed from the 650. Before I hooked it up I tried to test it with the ohmmeter - it was the same as the one I took out - hardly anything at all matched what it was supposed to according to the chart. (Of course, I was looking at the 650 chart) - but the readings were all completely different from the chart. Most were just infinity. Anyway, hooked it up, cranked it over, same thing, no spark. Put it back in the 700, started fine. So I'm going to work on taking the flywheel cover off next, hopefully I can get that done in the next couple of days....

  • Anonymous Sep 05, 2011

    Your link above for the drum/rotor didn't work for me, so I'm using this from bikebandit and referring to the #'s here: http://www.bikebandit.com/houseofmotorcy...
    Anyway, I got the flywheel cover off (#15) and there was a small flat washer lying inside - not a good sign. Didn't see where it came from but then again its difficult to see down in there. I'm trying to take bolt #13 our to get the flywheel off but having problems. I assume it is a normal right-hand thread? (Meaning I turn it counter-clockwise to take it out - while wedging something like a screwdriver against the flywheel teeth so it cannot turn). Anyway would like some confirmation I am doing it correctly before I break something getting this flywheel off...... thx....

  • Anonymous Sep 08, 2011

    Well, I got the center bolt out, but for the life of me can't get the flywheel to come off. Any suggestions? This motor is still in the hull..... other than removing the large hose in front of it there's not alot of space.....

  • Anonymous Sep 10, 2011

    Wow that was a job. Got a puller but that thing was stubborn, but it finally popped loose and came off. Ok, other than the parts inside don't look exactly "new".... nothing obvious, just alot of grease/graphite-type stuff.
    Anyway, not sure what you mean next - you mentioned a "protusion on the drum/rotor" - I don't see any such thing. There are 4 plates on the inside of the drum, sortof like brake shoes, that pretty much cover most of it.
    Also not sure what you meant by that tab on the back, unless you are referring to what is pointed directly at by #5 in the pic. The pulsar on this doesn't really look like the pic, it is like a half-moon key, very similar to both 3 and 4 in the pic, only smaller. No tab sticking out like the pic, more like a wide half-moon on both ends just like 3 & 4.
    Anyway, next step? Do I put the voltmeter on certain wires and check as it rotates?

  • Anonymous Sep 10, 2011

    Nothing appeared to be scraping. I took a couple of pics - going to try to attach/send those as I did before. Starting on that now.....

  • Anonymous Sep 10, 2011

    Here are pics of the rotor, and also looking down into the motor....

  • Anonymous Sep 10, 2011

    Another view of the rotor:




  • Anonymous Sep 10, 2011

    I don't think it triggers off the key in the crankshaft. As you can see in the next pic I just sent, the rotor looks like it covers the key completely, and there's about 1/4 inch or more gap there that is just room for the rotor center part. There is nothing I can find on the rotor anywhere that looks like it has or ever had anything sticking out that would trigger something once around, it is a smooth as can be. The pulsar on the inside doesn't look corroded, just greasy. I can't find what the pulsar sees that triggers the coil....... nothing on the rotor anywhere I can find.

  • Anonymous Sep 10, 2011

    Forgot to mention, can't find anything in the manual regarding timing, other than

    15 degrees BTDC - 21 degrees BTDC
    15 deg BTDC @ 1250rpm
    21 deg BTDC Full advance

    Nothing about setting it or how to check.

  • Anonymous Sep 11, 2011

    Ok, I think we may have something now. Earlier when I tested the charge coil (B/W to Black) - I got those wierd readings, where it constantly kept climbing.... maybe something was grounding or shorting out with the hub on, I don't know. But now with everything apart, everything else unplugged from it, the readings are steady, and I'm getting readings nowhere near what they should be for the charge coil. I am sending a pic of both the wiring diagram & the expected readings (slightly diff from what you have above) - and here's what I get (same either way regardless of which probe of the tester is on what wire). Lighting coil = 1.1, Pulsar coil = 14, Charge coil = 1370. Looks like the Charge Coil is reading about 4 times the resistance it should. Could that be the problem?
    Also, I traced the wires from the thermo switch, black and pink coming into the electrical box - they show infinity, with the switch still in the block. Do I need to take it out and test it? What should it test?

  • Anonymous Sep 11, 2011

    Here is the schematic & expected coil readings:




  • Anonymous Sep 11, 2011

    Not sure what you mean - plug everything back in, put the rotor back on, and crank it? Which wires do I check to see if I'm getting a spark, or do you mean see if I'm getting a spark at the spark plugs? Gonna be out most of the rest of today, It may be tomorrow night before I can put the rotor and everything else back on to test that.

  • Anonymous Sep 11, 2011

    It's entirely possible that I may not have had EVERYTHING disconnected before when I tested the coil - I can't recall, maybe I just unplugged the wires I was testing, I don't remember. But now that EVERYTHING is unplugged this is what it tests......
    Regarding the thermal switch, when you say closed at room temp, does that mean I should read a dead short across the wires or infinity? I thought open meant infinity.... when you say closed at room temp, that sounds to me like with it in the motor like it is, I should be testing continuity across the wires from the thermal swithch, right? (Which I am not getting - it tests infinity).....

  • Anonymous Sep 11, 2011

    Unfortunately, no. It lists the starter relay, rectifier/regulator, ignition coil, fuel sender, the CDI resistance chart I sent you earlier, the readings for the 3 coils I sent recently, and the rest is about the starter, which we know is fine as it spins it over fine. I'm sending you the troubleshooting chart as I just noticed it does list the charge coil actually ahead of the CDI, pulsar, and ignition as checking/replacing in the troubleshooting tree.... out the rest of the day, will check back tomorrow - thx.

  • Anonymous Sep 11, 2011

    Troubleshooting tree for engine turns over but no spark/weak spark.




  • Anonymous Sep 13, 2011

    The link you gave me just now is rather ironic - my OTHER problem that I'm having (I have another thread here for that) - is a 1991 Yamaha XL700Z - exactly what the link you sent is for - and I actually had already downloaded that manual as well - LOL.
    Anyway, I took all 3 coils loose from the shaft & cleaned them, inspected the wiring, etc, and put them back on - the resistance for the charge coil is now around 1500. I don't know how I could test it directly, the brown wire disappears into it under the wrapping, I was unable to get the test probe to connect to it anywhere, and for the black I guess it just bolts to the wheel inside and grounds. Any ideas on how to test the resistance at the charge coil itself?
    Some time ago I tested the charge coil when cranking with the DVA, I was getting 42-47 volts. I couldn't get a solid answer on what it was supposed to be reading, 1 site said 30-50 volts, another said over 100. The XL700 manual says I should be getting 115-120 Volts, and if it is below spec, then the charge coil is bad. The charge coil was also listed pretty early in the troubleshooting diagram tree I sent you - and since it appears to be way out of spec, I suspect I need to replace that, would you agree? Looks like they run around $120-$150.......

  • Anonymous Sep 13, 2011

    I cut thru the insulation as close to the coil as I could and retested, same thing - ~1500 ohms. Found a new coil online at Atlantic Jet Sports for $50 - ordered & done. I'll let you know what happens once I get it and install it, it will be a few days now.

  • Anonymous Sep 18, 2011

    SUCCESS!!!!!! :-) Once I put the new charge coil in, the resistance tested 385 - right around where it should, well within limits. I put the rotor/drum and cover back on, plugged the wires in, and did a quick test - a good, strong spark going thru the spark plugs with them grounded against the frame. Put everything back together, cranked it over a bit, poured a little gas down the open carburator, and it fired up! Sputtered for a bit before I shut it off (it hasn't ran in like 6 years - I bought it from someone as a project). But it ran way longer than it would from the gas I poured in it, so it looks like I just need to get it out on water & let the sea foam in the gas do the rest (I had already cleaned out the gas tank, lines, & carb). Thank you SO much for your patience, above and beyond the norm. I VERY much appreciate the time, effort and patience you've given me on this problem. You rock!!!! :-)
    Now I can get it out of the garage and continue on my OTHER problem.... the 2001 700 Waverunner....... Thx again!

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Jeffrey Turcotte

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  • Master 8,991 Answers
  • Posted on Aug 13, 2011
Jeffrey Turcotte
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Hi, have you checked continuity through the kill switch on the handlebar? I don't have the wiring diagram, so not sure which color the wires are. You mention one of the green wires goes up to the handlebars, but which one comes back? Or, if none comes back, then the switch probably just grounds that wire when you flip it off. If that's the case, is the wire grounded regardless of the position of the switch?
If the kill switch is OK, I would try reversing the polarity out of the magneto.

  • 30 more comments 
  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 24, 2011

    Sorry, I was just looking at the schematic. What you would have to do is switch the wires that hook up to the coil. This is just to check if the coil polarity was reversed.
    Since this model runs on a battery, is the battery fully charged? If yes, what you could try is to disconnect the magneto to take it out of the circuit and just see if you can get sparks using the battery.
    If none of these things work, I recommend getting a service manual with the wiring diagrams. I saw one here:
    http://cgi.ebay.com/ebaymotors/1991-Yama...

    It says it has the wiring diagrams, and this is really what you need to make sure the CDI is properly connected.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 24, 2011

    OK, if the coil isn't new, let's test the coil. Take the wires loose and measure the resistance across the 12 volt terminals. The resistance there should be about 1 ohm. If it's less than 0.5 ohms, the coil is shorted. If it's more than a few ohms, it's open.
    Next check resistance between the high voltage output to the negative 12 volt terminal. This should be about 10,000 Ohms. If less than 5,000, it's shorted. More that 15,000, it's open.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 25, 2011

    Sorry, the ignition coil. The one the plug wires are connected to. The 2 small wires should have about 1 ohm across. The big terminal (with the ignition wire removed) when measured against the smaller negative terminal should be 10,000 Ohms.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 25, 2011

    OK, if it measures the same as the old one, odds are both are good. So next let's check AC voltage at the ignition coil while cranking the engine. There should be some AC voltage--not sure exactly how much. I'd say at least 0.5 VAC. There is probably none. I assume you have checked the fuse that is stuck in the cover, yes? So the next part to look at is the part that sends the timing signal to the CDI. There is a pick up coil at the crankshaft that senses a little protrusion on the shaft. There are actually 3 coils under the starter gear, but 2 of them are for the generator and the other is called the pulser. Look in your book to see which wires to the CDI come from the pulser and check the resistance of the pulser coil. Hopefully your manual says what it should be. I would guess a few Ohms.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 26, 2011

    Yes, sorry. Two different tests now. Backing up from assuming the ignition coil is good, first checking the signal to the ignition coil. You can leave it plugged in. Connect your voltmeter to the primary terminals of the ignition coil. Set the voltmeter to VAC and crank the engine. Record the voltage. Next, find the pulser coil in your manual and identify the wire colors. The pulser coil is under the starter gear with the magneto. Disconnect the wires from there and with your meter set to ohms, measure the resistance across the pulser coil wires.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 27, 2011

    OK, that's correct. The engine can run off the battery until depleted in case the generator isn't working. Sounds like your pulser coil is OK. On the ignition coil, you can measure that with the leads on or off the coil. Having both numbers would be good; however, I need to know the AC voltage. 11 volts is probably the DC voltage, right? Does your meter have an AC setting? Also, the engine must be cranking during this measurement.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    OK, the 11 VAC seems high, but the zero when connected is bad. It should not change that much when connected. And we have already tried switching the wires on the ignition coil, right? I don't get the sparks jumping from the plug threads to the frame--are you sure the plug is good?

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    OK, and how do the orange and black wires to the coil connect back at the CDI unit?

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    As long as one of those black wires attaches back to the frame, the box is grounded. If not, then you do need to have the box grounded for troubleshooting. It does seem like it's hard to get the wires wrong from what you are telling me, though.
    Sorry this is taking so long. You have had the starter gear off the crankshaft before, right? Going back to the pulser, I wonder if it's getting it's timing signal. I'm not familiar with that gear, but it looks like the pulser faces out toward the gear. Then there should be a protrusion from inside the drum that the pulser sees for timing. Have you seen that and if so does it look undamaged? Is the drum clean on the inside?

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    behind the timing gear there is not only the generator but also the ignition signal that is generated by the pulser. Your AC voltages at the ignition coil are not reading right, so I suspect something wrong with the pulse. As the gear/drum rotates, the pulser sees the timing marker once every rotation. The signal from that is used by the CDI to generate the signals to release the spark from the coil. Sorry, but we're down to the harder part at this point.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    The magneto is not needed to start the engine--only to charge the battery. However, the pulser is needed to start and run the engine. It just happens to be under that drum by the magneto, but has nothing to do with charging the battery. I really don't know what is preventing the sparks, but you have replaced every part of the ignition system except for the pulser and drum/rotor.
    As far as the magneto goes, you have verified the impedances and that is the primary failure mode for those. I have no reason to suspect there is anything wrong with the magneto.
    I'm not sure what you mean by the DVA, unless you are talking about an ammeter. An ammeter would be used to check the magneto current but not to check the AC voltage at the ignition coil. Checking the AC voltage is not a common practice you will read about, but it's something I tell people to do when they don't have an oscilloscope. If I had your jetski here, I would use my oscilloscope to verify the timing pulses from the pulser and CDI. Once you have inspected the pulser coil and protrusion on the drum/rotor, hash a mark on the outside of the drum the location of the protrusion. Then you will know when the timing pulse should occur as the drum rotates. When the system is working properly, you can get the coil to release sparks just by turning the key on and rotating the protrusion past the pulser.
    You can see the inside of the drum here:
    http://cgi.ebay.com/ebaymotors/ws/eBayIS...
    I think that tab on the back must have the timing protrusion on it, but the resolution in the picture is too low to tell for sure.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    pulser pic


  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    I would love to give you some tests for the CDI module, but I don't have the manual. If you have the manual, maybe we can figure it out together. What tests did you do and what readings did you get? Generally speaking, to measure resistances, you need to have everything disconnected. To measure voltages, you need to have everything connected and turned on.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    OK, I get DVA, but I use an oscilloscope instead. However, since you have the DVA, maybe you can see the pulser output. Before removing the drum/rotor from the crankshaft, hook your DVA to the pulser terminals with everything connected. Then crank the engine and watch the meter for a blip on every revolution of the rotor. If you are getting the blip, then maybe we can focus on testing the CDI module.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    Try using this link and look at the bottom of the comment window. Is there a button for "Pictures?" If yes, click that and browse to the picture to post it in the comment window.

    http://www.fixya.com/PostComment.aspx?th...

    A resistance reading can vary with polarity of the meter leads when there is a diode in the circuit.
    Voltages should read the same values put opposite polarity when you switch leads.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 28, 2011

    Cool. Can you run the pulser test again with the DVA set to AC?

    On the table, your have your meter set to kohms, right. We can get thru this pretty easy. The table shows the negative probe connecting to the wires as numbered down the left hand side and the positive probe connected to the wire numbers going across the top. Everything has to be disconnected. You can see for example when testing wire 1 against wire 2, with the probes one way, there should be 20 kohms but when the probes are switched the resistance is infinite. This is due to a diode in the circuit. On the ones that just have a dot, there is a capacitor between the wires that initially shows no resistance and then gradually the resistance becomes infinite. Can you try some of these again and tell me if the readings make any better sense this time?

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 29, 2011

    OK, that does sound like a bad CDI. I don't know if the other one would be compatible, but there is no harm in testing to see if it has the right readings. If it looks the same and has the same wire colors, etc. it is probably the same.
    There is nothing in particular that causes a module to fail, but it is never good to hook the battery up backwards. That is one way they might fail.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 29, 2011

    Sure, what you can do is enter a free question. Otherwise I will not be able to find it. Let me know here when you have entered it, and I will go find it. Will wait to hear from you again next weekend.

  • Jeffrey Turcotte
    Jeffrey Turcotte Aug 31, 2011

    well, it's a good thing you didn't buy a new one, but we're still a bit stuck. Hope there is something obvious when the rotor comes off.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 05, 2011

    from a picture I found online, it looks right-handed. These bolts always have locktite on them. Lock the gear up real good and use an impact driver to get it off.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 08, 2011

    I'm pretty sure they have a puller in the shop, but I think you're on the taper of the crankshaft. Did you try whacking it? Are there some bolt holes you could screw some bolts into? The puller would use these bolts and a bar across the center with a bolt in the middle to push in on the shaft. I always just build a puller for the odd case that doesn't fit my generic puller. Maybe a steering wheel puller will work, depending on how far apart the bolt holes are. From the drawing, it looks like there are 3 bolts (which is similar to the common steering wheel puller). If you can't beat it off and don't have a puller, use a plate with 3 holes for these bolts and thread a big fine-threaded bolt in the middle. You don't need to tap any thing as long as you buy some nuts that fit the center bolt. I can draw you a picture if this is not clear. Yes, it's a pain to have to make tools, but much cheaper than buying them. Don't bother unless the hammer fails to release the rotor, and don't lose the key when it finally comes loose.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 10, 2011

    Good work. So there has to be something on the rotor that gets closer to the pulser than anything else. That will trigger the ignition to let the spark go. Does it look like the rotor was scraping on anything inside? If it was, maybe the timing hack was worn off. Let me see if I can find a pic of the timing hack.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 10, 2011

    OK, those are excellent pics. I think from what I see that the pulser triggers off the key in the crankshaft. The key looks good. How does the pulser look where the key goes by? Is it corroded? If it is, I would take it off and clean it up. While it's off, see if you can find that spec again and check the impedance of the coil. I'm not really sure what the pulser sees that triggers the CDI module, but if the pulser is clean and has the right impedance, that part of the system is probably OK. Check to see if there is anything on the inner hub of the rotor that might be a trigger for the pulser. Sorry I'm not familiar with this engine, or I would be telling you exactly what to look at.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 10, 2011

    Does your manual say anything about setting the ignition timing? If it does, there may be a clue there as to where the problem is. The holes in the rotor are usually used to observe the timing marks while shining a timing light inside.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 10, 2011

    Hey, I was looking for more info on your ignition system and came across this manual. Wonder if it's good for your system?
    http://www.autocd.com/autocd/WV/XL700_F0...

    For example, it has this wiring diagram for ignition. Is yours the same?




    What this shows me is that the the pulser uses it's own shell as a ground for both coils. However, it supplies ground to the shell via the black wire. So, to test the pulser, you measure resistance between black and brown and then between black and white. I think you did this already, right?


  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 10, 2011

    yeah, I was thinking the key would be covered by that long hub too. So it must just be looking at the magnets in the rotor. I don't know how it would know which is which unless it just keeps firing the plugs on every stroke of the piston. I need to see what I can find out in this manual. The timing may be automatically controlled. As you have already discovered, there is nothing to adjust. The screws that hold the pulser down--do they have slotted holes that might let the pulser slide up or down?

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 10, 2011

    By the way, have you tested that thermo switch? Don't bother with the hot water. Just check to make sure the switch is closed at room temp.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 11, 2011

    OK, first try connecting the thermal switch wires and see if you can get a spark out of the coils.
    If that doesn't work, we'll look closer at the charge coil. I'll have to think about why it is reading different now.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 11, 2011

    A very good question. Sorry, my bad. The thermo switch is supposed to be open at room temp.
    So that is probably OK. So the charge coil is out of spec. I wonder if your other machine has the same pulser? I know, that would be a real pain to borrow. What I think I would check next is the impedance of the charge coil at the coil itself. If it's in spec at the coil, we have a problem with the wires or how the ground wire is connecting to the pulser. Let's not buy a pulser when yours may be good.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 11, 2011

    yes, when you saw the resistance rising before, I believe there was a capacitor in the circuit that was drawing some current. Even so, I don't think the charge coil is the problem. I could be wrong. Your pulser coil has a good reading, so it should be sending pulses to the CDI.
    If it is the charge coil, maybe it would show in the voltage test. Do you have those in your manual?

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 11, 2011

    You can get the voltage test procedure from the manual I'm reading for which I sent you a link. Your specs may be a bit different, but the procedure will be the same.

  • Jeffrey Turcotte
    Jeffrey Turcotte Sep 13, 2011

    cut thru the insulation of the charge wire near the coil and check resistance to the frame of the coil. If you get the same number, I would agree that it's bad. I'm just not sure that is the problem, but maybe the CDI needs that extra voltage to fire the coil. You might want to look for a used one, but then you have to make sure it's good--get some kind of guarantee if you buy it on eBay.
    It's unusual for the coil to have such a reading, as they usually fail by going lower than spec or infinite. To go higher than spec, there usually has to be a lot of damage or a problem with the lead wires. If the reading is different from the peeled wire at the coil to the frame, check the connection of the inner wire to the frame--that may be the problem. If the inner wire is buried under the windings, it may be too hard to repair.

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