Thumpstar 138 won't idle, only starts when choke on?

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1redback

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hi iv got a new o7 orion thumpstar with a 138 cc engine with mikinu carby my problem is it will only start with choke on and even then it runs crap dies when i turn choke off? i have brought new spark plug checked elect connectors,cleaned out carby set it to 2nd notch from top off needle,check exhaust for air leaks etc:confused:
 
It sounds like a blocked pilot jet to me. Has it ever been right or has it been crook from day one, If its been crook from day one get a new carby under warranty as it could be a fault with the carby.
 
idle

will run with choke on but runs crap backfires taking out pilot and main jets from carby today and try and replace them any ideas where i can get mikinu jets from im in perth and how much they cost?
 
nah cant help you with the jet bit.. yeh if it was running fine from start id change your jets and see how that goes
 
Just give the jets a good clean and blow out with compressesd air. make sure you get the pilot jet as well as the main.
 
sounds like its running a bit lean dude... i say that cos by the sounds of it if its only running with the choke on its forcing more fuel in... if you richen it up and give the carby a clean up that might help
 
i only say that cos if its been running and running well then there may be no need to replace things that just might need adjusting...
 

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