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New and need some help

2297 Views 10 Replies 7 Participants Last post by  trapper1306
hey guys im new here but ive got a question, i have a 1987 trx250x that isnt running right, it has a popping/breaking up efect from half to full throttle.. everything has been thoroughly gone through, air filter clean and carb was cleaned twice. it seems to come down to the carb isnt jetted right. but the problem is the jet thats in there has no size on it so i have no baseline to start off and know what size jets to buy..

i was wondering if anyone can give me a rough range of what size jets to try in this carb to get it running good heres the mods: uni filter, coffmans race exhaust, hc piston, high lift cam, head ported, stock carb.. the pilot jet is a 35..id also like to rejet it with the airbox lid off for better performance. thansk in advance for anything you guys got!
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thanks a ton guys! ill update you guys after i get the pats in! cant wait to get this running again
sorry to bump this thread back up but thought id update you guys! after cleaning the carb 4 times and trying different jets and needle positions finally found out the accelorator pump was the problem! it was engaging to quick and flooding the motor, took it off and bent the lever a bit and put main jet from 125 to 130 ruinning amazing now :D
yeepper plug is looking good! i ran it for months with a 125 jet in it, we figured why this happened was the emolsion tubes were clogged with dirt, leaning out some of the fuel and allowing it to run until some of the dirt broke loose dumping more fuel and causing the problems, after cleaning the carb completely it became extremely fat and worsened the problem, until finding the ac pump problem which fixed it! :D then took the air box lid off and boosted the jet size a bit more and its great! this was all done with my friend who builds motors of all kinds from llawnmowers to quads and dirtbikes to our 850 horsepower big block engines in our dirtcars, so im sure its done right, gunna be great to get back on this thing and ride it!
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