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quick 90 carb Q

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Is there a clip on the throttle inside the carb to adjust the throttle needle position? I KNOW there's a clip, but is it adjustable?

I don't think the previous owner messed with the jets, but we added an FMF and a UNI filter and the sparkplug is still black and lightly sooted :banghead:

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yes there is, but i left mine in the middle. i moved it to the leaner position and it was overheating, so i'd leave it in the middle position, but go up a size on the main and pilot

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Maybe thats what I should adjust... the needle. I have a twin air filter w/ airbox de-snorkled. Modded the exhaust insert. Went up on the main and pilot. I have a bog that I cannot get rid of. Played with the fuel/air screw to no avail. Maybe the needle is the ticket. Ill try that tomorrow.

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I have a bog that I cannot get rid of.
is it in the bottom end...like when your on the gas hard and let off then back on it hard??? thats what my ttr 125 does and i cant figure it out...i might have to give that a try also :banghead::applause:

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is it in the bottom end...like when your on the gas hard and let off then back on it hard??? thats what my ttr 125 does and i cant figure it out...i might have to give that a try also :banghead::applause:

Yep thats it. I think its partly just a non pumper carb 4-stroke glitch. But I think It can be made better.

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The reason I don't feel like messing with the jets is that it really seems to run PERFECT like it is. starts first kick, no bog anywhere, with instant throttle response. He doesn't spend much time at WOT, because of the way the trails are here, so maybe the clip adjustment would work. I'll play with it the next time we dig into the carb.

What I'm wondering is why am I running rich instead of lean :banghead: Stock jetting with a better airfilter and exhaust shouldn't run rich :applause:

BTW, we still run the snorkel. I know of at least twice that it has saved his engine🤣 One river crossing and one skinny, DEEP puddle 🤣

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RyanK

The previous owner must have put in a bigger jet (main or pilot)...or drilled the stock main jet out. You are right. With opening up the breathing you should be running lean instead of rich. I don't have the original carb on mine, but I think the stock main is a 90 if I remember correctly. Order a 95 and play with the airscrew a little bit if you think it's a main jet problem. If you are curious about whether the other guy drilled out the main, just measure the new jet with the one that's in there using the shank end of small drill bits.

You mentioned that the bike doesn't get much WOT, so I would probably check the pilot jet first, since that's the jet he probably runs on most of the time. I think the stock pilot is 112.5. If you already have a 115, you could go back to the 112.5 and see if the bottom and mid range throttle response is still crisp. If it is, then that might fix your problem.

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Yep thats it. I think its partly just a non pumper carb 4-stroke glitch. But I think It can be made better.
hey thanks ill have to give a try...hopefully it works.

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RyanK

The previous owner must have put in a bigger jet (main or pilot)...or drilled the stock main jet out. You are right. With opening up the breathing you should be running lean instead of rich. I don't have the original carb on mine, but I think the stock main is a 90 if I remember correctly. Order a 95 and play with the airscrew a little bit if you think it's a main jet problem. If you are curious about whether the other guy drilled out the main, just measure the new jet with the one that's in there using the shank end of small drill bits.

You mentioned that the bike doesn't get much WOT, so I would probably check the pilot jet first, since that's the jet he probably runs on most of the time. I think the stock pilot is 112.5. If you already have a 115, you could go back to the 112.5 and see if the bottom and mid range throttle response is still crisp. If it is, then that might fix your problem.

Thanks Mitch. I'll check it out the next time I pull it apart.

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Hey I figured out my hard starting problem. Pilot jet was plugged. I sprayed carb cleaner and air thru it but it was still plugged. I could see light thru it but it was plugged. Took a little piece of wire thru it and wala out comed the crud. Starts perfect now. Adjusted the fuel screw and no more throttle bog. All is well.

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