help Rich or Eric

[smrmx]

I got a 1995 yz 125 that someone put a 2000 cylinder on it after talkin to Eric I put a 2000 piston with a 1038 wrist pin bearing.Problem is bike still won't start.cylinder is brand new from dealer.Have good blue spark and is getting fuel.It tries to hit off and on but just won't run.any ideas you guys are the only people I trust when it comes to bikes.

 

[todd36]

If it has good compression, nice blue spark and the timing is right I would look at the fuel system. What does the plug look like after trying to start it?

 

[JD_MXRacer]

fine then i wont share my very useful knowledge :fft:

 

[MXSparx]

You can share. We'll just make you Rich for a day :)

 

[Rich Rohrich]

As todd36 suggested, you have to start with the basics.

Make sure the reeds seal properly, verify the ignition timing (if possible) , make sure the cdi connections are clean and tight, verify the coil has a good ground, make sure the plug wire is clean and undamaged, make sure you have adequate compression, and make sure you are getting enough fuel to start it but not so much that the plug gets doused and fouls.

Once you are sure you have those things right it will tend to start. ;)

 

[smrmx]

I have checked all those things. I have checked cdi and stator with donor bike . but I wasn't sure because of the cylinder if that was the cause.1994-1996 crank same 1996-2000 cylinder same so I think it should work just very strange.
I don't think I overlooked anything but not sure.

 

[smrmx]

I figured it out the old owner put a 01 stator and flywheel on the bike.flywheel key is in different place.I retimed it and it started right up.


thanks


:ride: