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my she has 34 mm carbs and its jetted main 158 and pilot 58 that just dont sound rite to me could you guys give me about what it needs to be jetted at or what yours is jetted at

Those are big carbs, what type of mods do you have and what's your elevation? What doesn't sound "rite", have you ridden it and checked the plugs, or does it smoke a lot, or any other info?

 

Scott

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yea it smoke quite a lot and the plugs are really really black and it bogges on bottom mods are pipes no air box v force reed and spacers podesign air intake ported milled head and bored 40 over thats bout it

well hell.

 

The reason your plugs are black and it smokes so much is due to your jets being to rich. Do a wide open throttle test, run wot, kill it and if they're black adjust your main jet down to where they are a dark chocolate color. Then let it idle and check them, and adjust your pilot likewise.

 

I'm not too familiar with jetting those big carbs, but with a little trial and error you'll get it right on.

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Only one way to find out, you can't hurt a motor by going richer. If your plugs are black and oily, thats only for one reason, well, unless you mix a 10:1 premix, that might be a problem.

 

Hell, throw in a 300 and see what happens. I'd never say I'm an expert by any means.

 

One thing, you need to run your machine at wide open throttle in the highest gear you can get it in at high rpms, and kill the motor to check the plugs. This will rule in or out on your main jet. If its not oily, and its only oily at partial throttle, you might only have a pilot jet problem.

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Those carbs are too big for your mods, I know that from experience. I had the same carbs....I was running 162 mains w/ 50 pilots...sounds like your pilots are too rich, not the mains , but do a wot run in 6th gear for 5-10 seconds and check the plugs for the mains....My carbs were also sent w/ 58 pilots and were way too big....Even after I got the jetting as best as I could, I was still 8hp down from stock carbs on the dyno...the carbs are just too big unless your dragging and doing a radical port job or stroker.....Good luck

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damn man adjust them down there already 158 cant go t much farther

lol i was think maybe like adjustin them to normal bout 260 300 somehwere in that ballfeild

One thing, when you go up in carb sizes, your main jets will get smaller due to the size of the carb. I was at 310 with my stock carbs, I run a single 35mm now and am at a 180, with dual 34s you may be at 160 or something like that. Make sense?

 

Banchetta knows his shiznit when it comes to jetting too, I'm sure he's right. 34mm carbs are big honkers and generally can be overkill for general riding/mx.

 

Take it easy and let us know when you get your compression numbers.

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