Several things can cause the problems you describe. 1) If there is a mouse nest in your waterbox, adding water to the nest plugs the exhaust causing the poor running. When it drys out on land it runs fine. Cleaning out the water box will not be easy on that model but a careful inspection of the exhaust outlet may tell if critters are the cause of your problems. 2) Corrosion in the teeter/totter needle inside the carburetor can also cause low power on the water. Try cleaning the carburetor. Warning: be very careful not to modify or stretch the spring on the teeter/totter. 3) Water in the electronics box can cause shorting and low power. Open the electronics box and inspect it for moisture. Leave it open over night to dry it out and put grease on the o-ring seal when reinstalling the cover. 4) One last possibility would be burnt or stripped screw on tops on the the spark plugs (if they are not solid top plugs), fouled spark plugs, or burnt out resisters in the in the spark plug caps. Replace the plugs ($3 each) and the spark plug resister caps($5-$8 each), make sure the screw on domes of the plugs are on tight. with any luck one of these checks should fix the problem you describe.
The "waterbox" is the last large piece of the exhaust before the exhaust is vented overboard. The exhaust gases are bubbled through water to quiet the exhaust noise. On Yamaha's diagram it is part #2 "water lock comp"(you guessed it). If a nest has been built in the box whenever it fills with water and the nest floats it covers the exhaust outlet of the box causing the type of problem you describe.http://www.bikebandit.com/houseofmotorcy...
Often the water that gets into an electronics box is condensation not lake water. the only way to check for this is to physically open the box. I usually just leave the box open to ensure that it is completely dry when I reseal it. If moisture in the box is the problem usually it is fairly obvious but it is worth opening it up and drying it out just in case. I have dumped anything from a teaspoon to a tablespoon out of electronics boxes before.
The teeter/totter needle as I describe it consists of part # 32,33, and 34.http://www.bikebandit.com/houseofmotorcy...
If a little bit of corrosion or dirt gets into this set up the fuel does not flow through the carburetor. Every jet ski I have ever worked on/restored has needed this mechanism cleaned and it is another thing that can cause the condition you describe. I certainly hope that one of these fixes gets you back on the water cause labor day is almost here. Except for cleaning out a can style water box ( the Kawasaki boxes split into halves) most of these fixes usually work can can be done fairly quickly and easily.
Both carburetors have the needle assembly under the cover. If you lay a white sheet under the carburetors to catch any falling parts you can take the covers off the carburetors and clean the needles with the carburetors on the machine. Four screws will allow the removal of the covers. Yamaha's often have enough room to work in the hull this way. If you do not feel comfortable working in the hull remove the carburetors and take them to a work bench. Be very careful not to stretch or alter the tiny spring (part#34) in any way or the needle will not open and close properly. The needles are on the bottom corner of the carburetors and often fall victim to a drop of water causing them to corrode just enough to stop the fuel from flowing. I have carefully taken many jet ski carburetors apart and cleaned them, successfully putting them back together using the same gaskets and parts and had them work perfectly. If you notice damage to the needles or tear a gasket you may have to purchase an expensive carburetor rebuild kit (around $45) at the dealer. I think the carburetor cleaning should fix the problem.
Try checking/resetting your High and Low speed jets.
700 - Low Speed – 5/8 +/- ¼
High Speed – 5/8(M), 1-1/8(P) +/- ¼
Source:http://server1.sbtontheweb.com/forum...a...
Turn the low speed screw in till it lightly seats , then turn it out 5/8 turn, that is your starting point. It should run fine with that setting. If it does not quite feel right you can turn the screw in or out up ti 1/4 turn to tweek the performance (jet skiing in Denver at 5000 ft as compared to sea level 0 feet). Same with the high speed jet, screw it in till it touches lightly then back it out 1-1/8 turn. That is the correct setting for the high speed but you may have to adjust it up to 1/4 turn in either direction to fine tune the ride. If everything is working as it should ( clean carbs, good compression, good spark, etc.) the standard settings should make your boat run the way it should at sea level. Both carburetors should have the same settings. I copied and pasted the settings and do not know what they meant by M and P. Like wise Front and Rear is wrong. If any thing, it should be L and H for Low and High speed screw. Both carburetors low and high speed screws should be set the same (5/8 low and 1-1/8 high). I do understand the amount of work it is with duel carbs. My 750 Kawasaki is the same way. Fortunately the standard settings worked first time, no fine tuning necessary. I live at 950 ft elevation.
Both carburetors, high jets, should be set at 1-18 turns out from seated(not inches out). Both carburetors, low jets, should be 5/8 turns out from seated position (not inches out). I worked on a friends dirt bike carburetor that had the mixture screw out 6 turns. The main jet had fallen into the bowl and the vacuum piston spring was incorrectly installed. When I fixed the issues and put the mixture screw to the standard setting for that machine ( 1-1/4 on the mixture) it ran perfectly. If all the issues with your carburetors have been dealt with you should be running again on the standard settings (turns out from closed).
Lets go back to the beginning. Have you replaced the spark plugs and the Spark plug caps? It sounds like a fouled or partially fouled plug and possibly a bad spark plug cap. If you are having problems with leaking gaskets/oil on the outside of the carburetors, clean the carbs again and replace all the gaskets and diaphragms with new. Some kits include new springs for the needle assemblies, consider replacing the springs too. If they are altered in any way they can cause a carburetor to malfunction.
50 :1 is the correct ratio to run your boat on Pre-mix.
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I'm sorry, you'll have to be a little more specific for me. What exactly is the "waterbox"? I'm looking online at exploded diagrams, the only thing I see large enough for something to have built a nest in is called the "Water Lock Comp", and is the large metal cylinder in the back compartment opposite the battery. Is that what you meant?
Also, I see nothing in the carburator diagram called a "teeter/totter needle". Can you please tell me exactly what that is?
As far as the electronics box goes, it is dry - again, it runs just fine when not in the water. If you just sit it in the water and try to start it up the problems begin. I don't even get far enough to get anything wet - LOL. There is no hose spraying water or anything I can see that is getting the electronics box wet in the least so it is fine.
The spark plugs and the ends are brand-new.
Well the water box was fine, I took it out completely and flushed it, nothing floating around in there.
The electrical box was also fine and dry, as I was sure it was because as soon as you take it out of the water and put it on the trailer, fire it up for a few seconds to pump the water out it goes back to running fine, I knew condensation wasn't going to be dried out of the box that fast.
As for the carburator, I need a little more clarification. I think from the diagram that carburator 2 is the one towards the front of the waverunner & carb 1 is towards the back, correct?
I did notice that on carb 1 43, 4, and 9 were missing - the adjust screw for the throttle. Could this be why it will not idle?
As for the parts you mentioned, 32,33,34 - do I have to take the covering off (35,36) to get to them?
Well I took both carburators off & completely cleaned them. The front one seemed fine but the back one seemed to be a little plugged both under the needle valve as described and also there was some gunk under the plate on the opposite side (part # 18) which I cleaned up. Made sure everything was clean & blown out, gas flowed freely everywhere. I put it back together, once again it started & revved up just fine on dry land, I headed to the water with high hopes. But as soon as it slid off the trailer into the water starting/running it was the same story. It would fire but you can't get it to rev up without it sputtering & dying. It will not idle either, you have to just keep bumping the throttle a little bit and "goosing" it along to keep it running. I DID finally manage to get it to sputter along long enough that I got it past that point and could hold the throttle wide open (as I did 1 time before) - and as long as I held the throttle all the way it would run, but not nearly with the power it should and not very well. Very "doggy".... maybe 20-25mph tops, bogging down when turning or if I dared to let off the throttle even a little. A time or 2 it did seem to try to "surge".... it would suddenly start to rev up and I would get a rush of thrust but then it would bog back down. Of course, once out of the water and no longer under load it would run ok again after a few seconds of getting the water flushed out. Other than the diaphrams (#35) seeming a little dry everything looked fine in the carbs. Could those be the prob? They really only looked dry because I took it apart & they set out for a bit..... at this point I'm wondering if it is just some carb calebration that is off? When under load it just isn't getting the gas it needs? I cleaned out the tank & blew out all the lines previously, new fuel filter, so gas is getting to the carb no problem. One other thing I have noticed when taking the spark plugs out they seem more oily than I'm used to seeing. Could this be because it just isn't firing & burning the fuel cleanly, or is it getting too much oil into the gas? I would think not because of it revving up fine when on dry land/not under load. Anyway, any other suggestions?
Can't find that site as the full link isn't posted..... and I'll need some further explanation as to what you mean by the above.
I found the settings athttp://www.autocd.com/autocd/WV/XL700_F0...
I'll check/set them per the manual & test again.
I need a little clarification on the carburator settings. When it says "Low Speed - 5/8 +/- 1/4 (turns out) - does that mean after screwing it in until it is seated back it out 5/8 of a turn, +/- 1/4 turn or 5/8 of an inch, +/- 1/4 inch? I found another site that had the same specs but said "back out by the specified # of turns"..... so I'm guessing # of turns, correct? (Anyway, the low speed jets were WAY farther out than that..... like 4/5 full turns - more like 5/8 of an inch, which is why I'm asking for clarification).
Also, in your description above, what does the (M) & (P) signify? Is that which carburator? I have another diagram that says 5/8(F), 1-1/8(R) - is that Forward & Rear, with Forward being towards the front of the jetski?
Also, if it mentions plural (screwS) - but doesn't show on the diagram, I assume that means the same screw on both carburators, correct?
Sorry to have to be so specific, but it is a job & travel to get to a place I can put this in the water to test, so I like to make sure I am absolutely correct before I go to the trouble. Thx.
The diagram also shows
Ok that definitely confuses me with what the manual is saying. It has a section that says "High Speed Screw: 5/8(#1), 1-1/8(#2) +/- 1/4 turns out"...... and then the next line says "Low speed screw: 5/8 (#1) +/- 1/4 turns out".....
Another one I see has totally different boxes for high speed & low speed screw settings. In the box for Low Speed, it says 5/8 +/- 1/4, in the box for High Speed, it says 5/8(F), 1-1/8(R) +/1 1/4.
So it appears to me that for both carburators, the low speed screw on each should be set to 5/8 turns out. My confusion is on the high speed, it appears that everywhere (even in the settings you pasted above) - they list BOTH 5/8 and 1 1/4...... so what does it mean that they list 2 different settings for the high speed? It seems to me that it has to be diff between the 2 carbs.... either way, the high speed screws were both fairly close, but the low speed screws on both carbs were out about 4-5 full turns each. Hopefully I can test it out this weekend & let you know what I find.....
Well, I set both carburators as stated, it runs/revs up fine on the trailer, I took it to the lake this afternoon, same thing. Soon as I put it in the water I can't get it to run more than 5-6 seconds, and can't get it revved up. I ALMOST made it out to the no wake buoys befor finally giving up. I would start it (it starts right off) - baby it goosing it ever so slightly for 5-6 seconds limping my way back before it dies. (Same thing heading out, it does it immediately when in the water). It just simply will not run/rev up when it is under load.
Well, I only cleaned the carbs before, should I go ahead and put a carb kit in each one?
One other thing I notice, the carb sure does seem oily on the inside when I take the intake off.... and the spark plugs seem awful oily as well. I'm guessing because it isn't running well the fuel isn't being burned up cleanly..... is it possible that it is getting too much oil mixed in the gas? Would/could that only happen under load?
Yes, I have brand-new spark plugs, but have not replaced the caps. It runs fine when not under load so I figured it was getting a good spark. It isn't oil on the outside of the carb I'm seeing, it is on the inside. When I take the intake cover off the 2 wire mesh filters are very oily, and when I take the spark plugs out they are also very oily - the part that is down inside the cylinder. It's like an awful lot of oil is getting mixed with the gas but maybe that is normal, I don't know. I will order carburator kiits tonight and check back with you once I get those in and re-test it.
Well, sorry its taken so long, but I finally got the carb kits & rebuilt both carbs, one was a little dirty inside, but nothing bad. Anyway, I think I may have stumbled onto the problem - its one I've wondered about before & mentioned.
First.... I put the newly rebuilt carbs on (just the carbs) -hooked up the fuel lines & linkage, and fired it up. Purred like a kitten, and revved up just fine. Now this is important to note - when I would let it idle, and just nail the throttle, it would instantly rev up without a hitch, no problem at all. Of course I didn't run it very long..... let it cool off awhile, did it again, same thing, no problem, not even a hiccup.
So then I put the carburator cover on, (where the oil lines connect and go in) and the screens & intake (the screens are clean, getting plenty of airflow). Then when I started it, not only did it idle rougher, but when I would try to rev it up, it would sputter a little before revving up, and not really rev as high. Just like it does when in the water, only not as bad. But not nearly as smooth as it did without the carb cover/oil on. Remember I mentioned before things were awfully oily, and the spark plugs seemed to have alot of oil on them when I took them out? Well..... could it be it is getting too much oil mixed into the carb? Is there a way to adjust it? I'm thinking, as a test, disconnect & block off the oil lines to the carb and just mix the oil in the gas and see how it does...... what should the ratio be if I do that?
I finally gave up and took it to the mechanic. They said it is the intake reed valves.
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