T250 Jetting

[Tripleking]

I finally have the 71 T250 (with a 73 GT250 engine) running. It idles well, but it breaks up around 5,000 rpm. The carbs are Mikuni VM26-8074s. I installed #35 pilot jet and left the factory-installed #190 main in place. The exhaust is stock, but the air filters are small Emgo pods as the factory air box was missing. I left the large main jets in so as not to lean it out. I figured I could always step it down. The question is, what should I step it down to? The cylinders were bored out 1.0mm. I will recheck the timing as well. Any ideas would be most appreciated.

Thx

[tz375]

EMGO pods in general flow worse than stock OEM filters. Throw them away and find a pair of long UNI filters. UNI will filter better too.

[Tripleking]

OK, but should I down size the #190 jet with the Unis? I was planning on selling the bike and just want to tune it for the next owner.

[tz375]

I would start with main jets two sizes LARGER than stock to allow for the free(er) flowing filter if you fit UNIs.

[Tripleking]

OK, I will look up the oem jets.