genuine thumpstar 124cc (50-style frame) stalling issues

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user 20441

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hi guys,
so i got this all genuine thumpstar, incl (fake?) mikuni 22mm carb.
starts really well, runs nice on choke but once getting warm ,it starts cutting out/sputtering.
these symptoms can be counntered with a little more choke 1/3 to 1/2 choke.
most likely i'm running lean but want your opinions.
setting for pj is 15 ,mj is 97.5
allso have no means to get to the mixture screw since it's at the bottom of the carb and its too damn close to the freakin' hot engine :p neither with a 90* angle philips screwdriver, not enough space to fit one...
 
solved the stalling issue by putting a bigger PJ, from 15 to 17.5.
now just need to lift the needle a notch and see it gets better response.
rear suspention needs pressure, can i just add air or do i really need nitrogen to keep it cool?
 
Hey mate.
You should be able to get a small Phillips bit with either a small shifter or a spanner to adjust the mixture screw.
Some tyre places can fill the piggy back chamber up for you with nitrogen. Air does work but isnt really recommended.
 
i put a philips bit on a rubber tube wich is flexible enough to reach the air screw.
as for the rear shock, i tried putting about 7bar pressure onto it ,but that doesn't really make any difference.
from what i recall from a previous (big) bike, it needed about 10 bar of nitrogen...
at 7 bar it's still more or less a pogo stick in the back...it's not leaking or loosing air pressure...so don't know if its broke or not...
 

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