Carburetor Help?

[Miller52]

Hey guys I have a Demon X XLR140 and when i ride it i can have it in any gear from 1st to 4th and when i am barely on the throttle just putting along to almost half throttle it spits and sputters and i cant think of why. the main needle thats hooked to the cable? idk. also i had another question because i normally ride my quad and have never been very used to a twist throttle can i put a thumb throttle on my pit bike easily without having to shorten the cable or anything?

All help is really appreciated, Thanks!

 

[my67xr]

welcome to Miniriders,


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sounds like your Pilot Jet could be blocked. ? what carby is on it ?


and yeah, you should be able to fit a thumb throttle, i have done it before.
it is normally the other way around though.
quad owners fit bike throttles

 

[Miller52]

sounds like your Pilot Jet could be blocked. ? what carby is on it ?


and yeah, you should be able to fit a thumb throttle, i have done it before.
it is normally the other way around though.
quad owners fit bike throttles

not for me its not the other way i cant get used to the twist i have ridden for 18 years on thumb and its a molkt carb but idk what size its stock

 

[my67xr]

i would be pulling the carby down and blowing it out thoroughly.
if you pull the carby off, and then remove the fuel bowl, and dry the fuel bowl gasket/seal asap to stop it swelling.




on the underside you will see the Big brass Main jet in the centre,
and the Pilot jet slightly towards the front, down in the tube shaped recess.
remove the pilot jet and blow it out well, maybe poke a strand of wire from a wire brush through the hole to make sure it is open/clean.
also where it screws into the carby , if you look down into the threaded part, you should be able to see light into the carby bore.
there is a tiny hole that can block up in there too.

blow out all the ports in the carby with compressed air if you can.
remove both the jets, and also the mixture screw,spring and gasket/o'ring if it has one there first.


there are 2 or 3 ports on the air filter side of the carby intake,
blow compressed air through there and you should be able to feel it come out from one of the jet holes in the bottom of the carby.



the base setting for the mixture screw when you refit it is between 1.5 and 2 full turns out

you will need to adjust the mixtures once it is all back together and refitted.