i finally got the thing to run, not sure what it was but its fine again, with the same old plugs that caused problems before. now im thinking that maybe it has an air leak. i checked everything obvious, fuel lines, carby mount, hsn mount, tank, head, but i noticed that it takes many pulls of the starter cord, with the exhaust plugged to get fuel all the way to the carby. and then when its running, as it gets warmer/less fuel it starts to run lean and uneven. i have to turn the idle down so it doesnt explode it almost seems. i am running the low needle a tiny bit rich(1&2/3 turns in from being flush) hsn is set quite rich(nearly 2 turns out) and its set so that when cold it idles without trying to move. has lots of compression still(10 tanks old) and can still feel it with the flywheel test, and on the pull cord. im at a loss right at the moment. any help would be great. thankyou.

Please try the FAQ page. We have several on getting R/C car engines set up and running..

http://www.osengines.com/faq/product-faq.html