I posted this before but I’m new and posted it in two places and got it pulled. Sorry.
I have a 96 YZ250 that I purchased at the beginning of summer this year. It has always sputtered badly after starting then after warming up idles poorly. It kills very easily and is super hard to get started even when warm. The other day I went for a quick ride for about 500 yards when it just died. It made a hollow noise when giving it gas and acted as if the choke was on – it was not. Since then I can’t even get it to fire off – it will turn over just not fire off.
Here is what I have done to troubleshoot – not necessarily in order:
1.Pulled and cleaned the carb - jets were clean/clear and the needle is set at the middle position.
2.Checked the floats – They are at spec and look almost new.
3.Replaced the reeds
4.Replaced the spark plug and cap
5.Checked spark against the head – pretty good but could be better
6.Tested the coil resistances per the Clymer manual - In spec
7.Tested the stator coils per the manual – In spec
8.Pulled the flywheel and cleaned the stator and checked connections
9.Pulled the silencer to check for obstructions – repacked
10.Checked the kill switch – OK
11.Cleaned the filter – Didn’t really need it but….
I am getting spark albeit a little weak, I am getting gas because I can smell it and see it on the plug. I don’t think the jetting would cause it to suddenly stop working after working for months. It may run like crap but just stop??? The stator plate did not appear to have moved. I would think that I could advance or retard it to the extremes and still have it run, maybe not good but still run. The compression seems good. I didn’t test with a meter but it will blow your thumb right off the spark plug hole when you kick it. Maybe that makes no difference, I don’t know. The only thing I can think of beyond that is the CDI unit. Maybe the spark is just hitting at the wrong time????
I’m really getting bummed about this so any help you can give is greatly appreciated.
Dave. :bang: