I recently installed a new OS .37 in my Raptor 30, the break in and test flights went fine with no overheating. The other day I passes the TX to my son to get the feel of the new set up when all of a sudden the engine started bogging and stopped about 2 feet off the ground. Like a dummy I started trying to tweek the needles and of course that is not the problem, it does seem it idle and start OK. Tonight I tried a fresh jug of fuel with no improvements so I removed the fuel tank to check the pick up line, main line, filter and dissassembled the carb to check for blockage, no problems were found. I checked the OS #8 plug, it is very clean with a bright coil, I have not changes it yet. I have another problem, I cant find my box with instruction book to get my needles back to baseline, I think I left it on the bumber of my truck...DANG IT! If I get my needles back to factory settings, change the plug and it doesn't help, what can I try next? It got dark on mt tonight so I had to stop.

Thank you for your time!
David

Engine starts and will idle, just doesn't want to spool up.

www.osengines.com should have the manual.

I'd start at 2 turns on the main needle.

Sounds like its rich and cooling the plug and putting it out when it comes on to the high needle but without hearing it thats just a guess.

Since it did work I would look for the cause of the motor quiting, maybe a loose or missing carb bolt, loose muffler or pipe, cut fuel line...

Also check for a Crack in the Tank (Hows your Compresson?)

What's going on here??? I fired it up last night and it ran like a hit dog! I did install a new header tank, something I put off for some reason, maybe I got aroung the problem somehow with it? Kinda got me worried about it doing it again during forward flight, guess only time will tell. Thanks for everyones input so far.

David