I guess you're saying that a different pipe would give better performance? What would you recommend. I find it is very torquey on the bottom end now (more than necessary). I would be willing to sacrafice some of this for more horsepower on the top.

Ken

 

If you have a lot of torque on the bottom, you can gear it to use that torque for better top end. You could go to a .175 main and probably be safe. 20:1 is rich, you could go to a 32:1 and be safe as well. A pipe will make a big difference. There are many good pipes out there. The sparks TT pipe runs very well as does the esr trx-5 pipe.

 

fatty has done me good with my 250 and i hear some 310 guys find it to still make some power. paul turners hi-rev wasnt exactly cheap so i stayed away from that. what pipe are u running now? if your are still running the stock pipe id say their is a major factor. also sounds like your tuning is off. i would stay away from lugging the motor in high gear like u did before. 1/2 throttle in 6th gear(over drive if you're still running the stock sprockets) definately cant be friendly. with my mods below i run a 148 main and a clip down on the needle with 32-40:1. i put a little less oil than the measured 32:1 mixture prefix on the ratio cup. do a run in 4th gear WOT and kill the bike and pull the plug.

Here are some plug reading sites:
http://www.buckeye-illinois.com/sparkplugs.htm
http://www.amiles.com.au/rmr/SparkPlugReading.htm

My fav: http://www.eric-gorr.com/techarticles/sparkplugs.html