1995 TZR 125 - misfiring under load

[Stephen Kelley]

Hi guys, i'm new to the forum, and i really need some help with my bike.

I bought this TZR 125 a few months ago, the fairing were all smashed, but it was a good runner. So we've repaired the fairings, and now it will not run properly.

The first problem is that it will not start off the button, but will usually start off a bump, which is no big deal because its easy to bump. But since we've repaired and sprayed the fairings, the damn thing will not run. When its stationary on the side stand it will tick over and run, but not rev freely. But when i try to ride it it revs to about 4k and misfires and after a few seconds it will cut out completely.

Ok, so.. things we've checked:

Spark is fine

Carb is fine with new standard jets

Petrol tap is working fine, seems to be fueling correctly

Inlet manifold checked to ensure no leaks, new gasket and sealer just to be sure

Powervalve seems to be working correctly, goes through its self adjustment thing when ignition is turned on and turns when revved

What we havent checked.. because we don't know how:

Electrics - coils, cdi etc. Mechanical stuff we're fine with, wiring we aren't so good.

Timing (not sure if it can be adjusted)

And anything else we should have checked but isn't on this list hasn't been checked because we either didn't know about it or didn't know how to check it.

Things we haven't checked because we either think its an unlikely cause of the problem or a big job that we hope it isnt:

Head gasket, i know it can cause misfires if its losing compression. (We haven't done a compression test as yet because we can't find our compression tester).

And i can't think of anything else, i've been as thorough as i can manage. We built this bike back up for my 17th birthday (Friday just gone), and as of yet i've not been able to use the bugger!

Any help appreciated

Ste

[yamaha tzr 125 r (1995)]

Hi guys, i'm new to the forum, and i really need some help with my bike.

I bought this TZR 125 a few months ago, the fairing were all smashed, but it was a good runner. So we've repaired the fairings, and now it will not run properly.

The first problem is that it will not start off the button, but will usually start off a bump, which is no big deal because its easy to bump. But since we've repaired and sprayed the fairings, the damn thing will not run. When its stationary on the side stand it will tick over and run, but not rev freely. But when i try to ride it it revs to about 4k and misfires and after a few seconds it will cut out completely.

Ok, so.. things we've checked:

Spark is fine

Carb is fine with new standard jets

Petrol tap is working fine, seems to be fueling correctly

Inlet manifold checked to ensure no leaks, new gasket and sealer just to be sure

Powervalve seems to be working correctly, goes through its self adjustment thing when ignition is turned on and turns when revved

What we havent checked.. because we don't know how:

Electrics - coils, cdi etc. Mechanical stuff we're fine with, wiring we aren't so good.

Timing (not sure if it can be adjusted)

And anything else we should have checked but isn't on this list hasn't been checked because we either didn't know about it or didn't know how to check it.

Things we haven't checked because we either think its an unlikely cause of the problem or a big job that we hope it isnt:

Head gasket, i know it can cause misfires if its losing compression. (We haven't done a compression test as yet because we can't find our compression tester).

And i can't think of anything else, i've been as thorough as i can manage. We built this bike back up for my 17th birthday (Friday just gone), and as of yet i've not been able to use the bugger!

Any help appreciated

Ste

hi im new to this i have just bought a tzr 125 1995 and i have bump start as my starter button doesnt work the starter motor seems like it worker butt not turning enough with the engine i hope we both sort it as i just made a forum abt my problem thinkin someone may have some advice.