i have had many os engines and i love them. i recently bought a rb s3 for my truggy and i hate it. it doesnt hold idle very well at all but rips pretty hard from mid to high i know how to set my needles so do u think i have a lemon. i have heard rb motors are just as good as os so what do u guys think

For some reason I too have always found OS engines far easier to tune than NOVA's or RB

So it might just be a tuning issue ??

os motors are just easy to run but they dont have the speed.

Yeah I know!

I own 4 RB engines & they are all great. 0430, 0425, 0510, 0630. I have no probs with any of them. Set the needles to base factory setting. Run it up to high RPM & get the main needle to about 80%. At this point the engine should hang on a higher RPM for about 4 secs before settling down when you come off throttle. Tune the low needle just enough to get the " hang " to go away. then fine tune the high needle & you should have a good strong engine that runs about 230 deg on a #5 plug with outdoor temps in the mid 80's. If you can't get your motor to run good doing this you need to do the soapy water test to check for air leaks. Also you need to make sure your fuel tank seals fully by doing the blow test.