20 Most Recent 1988 kawasaki VN 750 Vulcan Questions & Answers

Either the clutch slips or the gear jumps out. Chech your free travel in the clutch lever the end should move an inch before feeling clutch tension. Drain the oil from the gear case and observe any metal fragments. anything larger than powder is serious damage and will get worse. Worn gears, bearings fragmenting will destroy all the transmission as the chunks circulate in oil. Flush with a quart of motor flush , Naptha, or diesel fuel. and drain completely . REFILL to mark with proper specified gear oil.

1. Remove the airfilter box and try to rev. it up but dont yank it up rev it up in a 3sec time interval from 0-9000rpm. If it revs up replace your airfilter it might look ok but the material it is made of ages and with damp in the air closes up the micro holes in it and chokes the engine as soon as you rev it up. If you have an airbox don't fit those smaller individiual airfilters you would have to get it jet dynoed, what I am saying is fit the same type air filter back on or you will have fuel air problems.
2. Remove the exhaust manifold from the head, start it up and rev it up in a time interval of 3sec from 0-9000rpm. If it revs up your exhaust is blocked and you either have a wasp stuck in your exhaust outlet or it is aged and blocked. Try closing your mouth and nose with your hands and breath in or out, this is the same with your engine.

3. If this does not rectify your problem you will have to look at your carburator float levels or your coil packs. Let me know if it work or don't so that we could fault find your problem this is the easiest and the firts steps to follow.

http://www.cyclepedia.com/motorcycle-vin-decoder/ Free and Easy!

sometimes automatic cam chain tensioners freeze up or run out of adjustment. if it's frozen up you can replace it with a new one. if it ran out of adjustment you can replace thecam chain because it stretched out or install a manual cam chain adjuster because they usually hve a little more room for adjustment.

Hi.

There is no "diagram" showing the whole routing of fuel lines in the bike. You need to use different diagrams in Fuel System section of the service manual. Fuel system section starts at page 15 in service manual, but what you really need starts at page 40. I have posted fuel service manual at the end of comment.

There is one forum where users discussed the routing. One user has colored the diagram from service manual to indicate lines routing. Here the diagram:



Here the forum, I quote:

"The red and yellow are the fuel lines that go to the petcock. The green one you left unmarked also goes to the petcock. The line with a question mark is a vacuum line that connects to a part in front of the battery along with the larger lines to the cylinders."

Here the service manual in PDF format.

Regards.

Ginko

sounds more like ring issue
poor some oil in cylinders , wait 5 minutes recheck (make sure you install plugs) if pressure is up it's rings if not probably valve (or melted piston)

no the camshaft profile is all wrong.

hot or cold you dont mention which, but make sure the fuel is getting to the engine is the fuel filter blocked ?, air filter clean ,are you getting a good spark?

Caburetor:
1.servicing caburetor,lool at feul jet.
2.there is a gap beetwen feul et and it stoper then jack up the stoper of feul jet.do it within cerefully.
3.testing by using a few feul in the bottle and plug in with hose pipe to caburetor.(doing this without assemble caburetor cap)
4.make sure when the flooter going up the feul jet will stop the feul.
5.make sure the flooter do not damage or hole(need replacement)
6.make sure when the flooter going down, a feul will going in that caburetor
7.than all clear.assemble it again and ready to put back at there place.

no , just figure 150-200 miles per tank

the whell base is 1585mm and the seat height is 750mm, these are all stock specs.

Hi Todd: Sounds suspiciously like it would be brake fluid. Check to see if it is connected to the rear brake master cylinder. (that's the thing that has a shaft that is connected to the brake pedal) Motorcycles like Grade 4.

There's a black plastic knurled knob under the left side of the gas tank that adjusts idle speed.

fuel comes out of air filters????!! no, definitely wrong

Your clutch is either out of adjustment or it's fried.

CHECK WIRING CONNECTIONS ARE NOT LOOSE .

Hi.

I have just sent you a comment on a different thread. I see that you posted the same question on separate thread. I am also posting here as I do not know if you are following both thread. Better to keep the problem on a single thread. Below my previous comment:

Hi.

There is no "diagram" showing the whole routing of fuel lines in the bike. You need to use different diagrams in Fuel System section of the service manual. Fuel system section starts at page 15 in service manual, but what you really need starts at page 40. I have posted fuel service manual at the end of comment.

There is one forum where users discussed the routing. One user has colored the diagram from service manual to indicate lines routing. Here the diagram:



Here the forum, I quote:

"The red and yellow are the fuel lines that go to the petcock. The green one you left unmarked also goes to the petcock. The line with a question mark is a vacuum line that connects to a part in front of the battery along with the larger lines to the cylinders."

Here the service manual in PDF format.

Regards.

Ginko

Just measure the voltage at the battery with the engine idling - in a normal system you should have around 14.2 volts. If its lowerthan that you will need to measure the voltage given by the stator, it should be above 14 volts AC. if you get that then the rectifier is defective, if you get less it's the stator itself.
Beware, the stator should be the 6 wire version, the cheap chinese copies, with 5 wires, are *******, they don't deliver more than 13 volts so it can't charge the battery.