Sputtering Stock 250R - 1989

[gac]

I need help. I have a stock 250R bike and it's sputtering in the upper middle and high end of the rev. I just cleaned out the carb and everything inside is stock. I have started to go down in main size and raised the needle - but wondering if any of you have experienced other - perhaps electrical issues? This bike has run stock for 14 years - not sure why I would need to rejet. Other than a piston a few years ago - she is stock

[Roostin250R]

your running the stock 34mm carb? and stock jetting from the factory? I assume it always ran good with this jetting until now? could be a number of things from bad gas to a dirty screen in your fuel petcock or a partially plugged vent tube on your gas cap overflow. not likely ignition unless maybe a loose wire somewhere. They usually work or they dont. If all else is in order, your carb may be just plain wore out. The stockers tend to do that after 15 years . I had the same problem with my 89 a few years back. It was just time to replace the carb.

[Aallron]

I just had the exact same problem on my 89 TRX250R, but the next morning it wouldnt start ... stator was the problem. It is just something else to consider.

[Dave83]

Check the stator and the couunterbalance bearing holder.The holder can break and allow the pickup to move and screw with the timing.Also,plug gap.

[RUNMYTA]

If it runs fine until the upper RPM's without a miss then starts to break down it is your coil and plug wire. Trust me I spent hundreds of dollars and a month of headaches just because a buddy gave me an "bad" used coil to try