alrigh tguys. i have a '97 honda trx250 recon. i plan to put on a t-4 pro circuit exhaust, a K&N air filter, and cu tthe end off of the air intake pipe. right now it runs a stock main jet of 95. does anyone know what i should change the main jet to? also, i have heard of doing a "plug chop" to test for leanness or richness. could someone instruct me on how to do one on a recon, being the autoclutch machine it is. any input would be GREATLY appreciated. thanks.

 

on an auto clutch machine, i think that the plug chop is somthing like you go full throttle (or w/e throttle position you want to check) then u push down the shifter *but do not release it* and at the same time you hit the kill switch. im pretty sure that will put it in neutral and should work. correct me if im wrong somone

 

hondarider300 thanks for the advice. thats what i was t hinking, but wanted to amke sure. anyone else have anything to add such as the main jet size? thanks

 

You will need to increas the main jet one size to begin with....that might be almost to much. I just re-jetted a 250EX (same motor) with similar combo's and the next jet was almost to much fuel, so I opted to drill out the factory to an in-between size, rasie the needle a clip.

Since that pipe will flow better than the one I just worked on, I would say go up one and leave the clip in the 3 position. Plug chop will do nothing for you on a 4 stroke (that is a 2 stroke technique since you need fuel to keep it lubed - most think it is universal technique, it does work on thumpers, but does nothing fro diagnosis) you need to jet it by feel and what the motor wants compared to how you are ridding it. If you putt around, no one would know their bike is running lean their whole life, but racers demand every inch of power - hints best carb setups. Try this, and re-jet according to feel. Print off the jet tech from www.carbparts.com, they will also be able to help you with tech question.

 

i would try around a 100 keihin mainjet.

 

dan250race, thanks a lot. my friend who is pretty good with this kind of stuff said that i might not have to go up any size on the main jet, and jsut mess with the air and fuel screws, and he also gave otu the idea of boring out the stock jet jsut a tad, and THEn fiddling with the air and fuel screws. i think i am going to get a jet one size bigger, and drill out my stock one. if the drilled out 95 isnt putitng in enough fuel, i will upgrade to the 96. tahnks again.

 

the next size up from a 95 is a 98.

 

oh ok thanks

 

call the pipe manufacturer or get on thier website. most have jetting specs. included with the pipes. jet kits include versatile info on elevation, pipe, air filter,etc.........and come with a variety of parts to get dialed in.