20 Most Recent 1989 Yamaha FZX 750 Questions & Answers

Sometimes a chain will come off a sprocket and get wrapped up at the casing. The casing usually will get cracked or actually broken. A replacement casing from the parts department comes without a full serial number. The 1FM designates the case to be a replacement casing. Legally, the dealer was supposed to punch in the original numbers from the owners title. The bike is special in that it is now 20 years old and is now considered an antique in most states.

Top rating for this answer? Thanks!

Saftey circuit issue! check clutch switch, side stand switch and wiring these are connect to the neutral light switch and the 3 are part of the saftey circuit, circuit is designed to cut the bike out if the stand is down and you kick it in gear also to stop the bike turning over & jumping forward when you hit the starter and its in gear and the clutch isnt pulled in.weak stand spring my not be pulling stand onto the stand switch correctly there fore no making the curcuit, switches just make and break the curcuit.

You will need to have it checked by local deal no easy fix to test your self

Sticking floats or worn float valve needles or incorrect float height, tap float bowls to see it overflow stops (sticky float), remove and clean float bowls and fuel inlet passage with carb cleaner and compressed air, check float valve for wear to the rubber tip. Reset float height by slightly bending the metal tab on the float to adjust the closing height of the valve measure from the carb bowl mating surface to the top of the float when fitted then re adjust 1mm at a time higher untill fuel doesnt over flow.

sounds like the floats are stuck. cleaning carbs should do the trick. its a good practice to start up motorcycles and let them warm up from time to time while being stored.

can it be push started?..if it cant and the rear wheel doesn't move then you have a siezed motor or the starter gears are stripped.if it can be push started guess what ? its your starter.

Better, get a new one. If you must remove slave cylinder, take out internal circlip, remove seals, wash in carbontetrachloride or similar, air dry, refit new seal kit lubricated with dot 40 and slide home, refit circlip fill and bleed air, topup, simple yea

Half a turn is too much - 1/8th at a time.
Check for air leaks at manifold - both at crankcase and at carb ends.
Does it run (idle) on its own, or do you need to keep on the throttle?
Have you checked the other end (the exhaust!) as well? A blockage there will be as bad as a lack of fuel at the front end.
Make sure you have everything in place - air filter, etc. - as with those little 2T engines, they are far more susceptible to thigs like that than a bigger engine.

Sounds like you have too much crankcase pressure.
That may be caused by excessively worn rings or valve guides, a hole in the top of a piston, or a crack between a cylinder wall and the crankcase.
All of which are pretty serious. The leak at the alternator is just a blown seal but the crankcase pressure must have been high for it to blow. first, carefully inspect the breather hoses from the crankcase and the cam cover to atmosphere. if they are kinked or plugged, that will cause the symptoms you describe. On some bikes there is a hose from the crankcase to the intake box. Be sure this is not blockes. Some bikes have a PCV valve, check that.
good luck.
Squim

10W 40

You most likely have an air leak in the intake tract. Check and make sure your vacuum hose or hoses are attached also check for air leaking into the intake behind the carbs. When the bike is running, spray carb cleaner between the rubber boot and the engine. If engine changes rpm you found your leak.

check starter and the solinoide and all wires are in good condition etc ! check startdr button ok too ! P...