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Discussion Starter · #1 ·
Hey guys, I have the tboltusa 20mm carburetor. Stock it had a #35 pilot jet and it bogged a lot and I was told to put a #38 pilot jet and I did and it’s still anywhere from a little more than half throttle to full throttle it’s like you’re hitting a kill switch where the bike just shuts off it doesn’t even spotter it just has no vacuum and it’s stalls if you ease into it slowly it’s fine, I originally had a 19 mm carburetor from Amazon and it works great it has no bogging but I wanted a bigger carburetor for a little more power and I can feel the power increase I just need to fix the bogging issue. Does anybody know what’s going on? Thanks guys.
 

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As the carb sits on your bike right now, what slot is the jet needle clip in, what size main jet is in it, and is the pod air filter clean and properly oiled?
 

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Discussion Starter · #4 · (Edited)
As the carb sits on your bike right now, what slot is the jet needle clip in, what size main jet is in it, and is the pod air filter clean and properly oiled?
It’s is a #89 main jet and the needle clip in on the top notch so it’s in as far as it can go It’s the air filter that came with it it doesn’t have to be oiled as far as I know.
 

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Relocate the clip in the 3rd slot (middle), where you have it now is leaning out the mixture for mid-range. Try going up to a #90 or #92 main jet, and see if the hesitation in the mid to upper throttle range lessens and/or goes away.
 

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Discussion Starter · #7 · (Edited)
Relocate the clip in the 3rd slot (middle), where you have it now is leaning out the mixture for mid-range. Try going up to a #90 or #92 main jet, and see if the hesitation in the mid to upper throttle range lessens and/or goes away.
Ok, Also if I go anywhere from idling to full throttle or even to half the bottle it bogs the same way the only way for it not to is to just ease into it, Even with the bigger pilot jet The bogging from Idol to even 3/4 throttle doesn’t change but I’ll try the main jet also
 

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Discussion Starter · #9 ·
How about posting up a video of the bike running and you working the throttle so everyone can hear exactly what is happening.
That’s the thing I’ve never been able to upload a video on here for some reason but if the bike is idling and I instantly go to full throttle it acts like there’s no engine vacuum to pull fuel into the engine and it dies but if I’m at quarter throttle and go to full throttle it’s OK with that for the most part
 

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What is the point of going from idle to full throttle? These carbs do not have an accelerator pump and cannot be wicked to wide open like a big bike with a pumper carb.
 

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Discussion Starter · #12 ·
Its pretty easy to do.....That would really help. It's a 4 stroke not a 2 stroke. Are you riding the bike to test it?
tmas
No im not when it’s under load it’s worse. In its above 3-3500 rpm and you go to wot it’s fine but if your at idle and go to wot it stalls if you hold it to long, same goes for when riding, I ordered some main jets so I’ll try a #90 and see if that helps
 

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You might want to try re-reading this post more thoroughly and establish a baseline to work from when making the fine-tune adjustments.

And, again, I ask, what's the point of trying to go from idle to full throttle?
 

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Maybe this can help, your pilot jet operates 0 to 1/4 throttle, and your main jet operates from 1/4 to full throttle. If your having problems running properly above 1/4 throttle then it will be your main jet. If you upgraded your carb and have an aftermarket air filter, then you might be getting too much air to fuel which means your main jet is to small and you need more fuel. good luck with your bike.
 

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The jet needle on the throttle slide plays an integral part in the 1/4 to 3/4 throttle range, that's why you have to also make adjustments to the clip one slot at a time, either up or down, while fine-tuning.
 

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I don't know your carb, but, I call that a lean bog. I would tune your air/fuel screw to nearly full RICH...for me that means screwing it IN, to nearly seated...adjusting the idle screw at the same time so it doesn't stall. Then see if it's any better. If that doesn't help, try going to the next bigger PILOT jet...try it again...repeat.
That's all I got.
 
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