Have running problems with a Magnum 52 four stroke, can't get a smooth run on it. I've tried several needle valve adjustments on both high and low end with not much results, just can't seem to lean out in a smooth steady purr. Has anyone experienced similar problems with this four stroke?

Thanks for looking,

Dick

I had simular problems with a Magnum 61 four stroke. You cannot ever decide where to put the needle valve and it generally just runs ruff with out as much power as it should have.

I put an OS 'F' plug in it and all the problems went away. The bigger Magnums that I had ran just fine with the offending plug.

Good luck,

Jim

These engines need a lot of break-in time, is it new? Also try different fuel and maybe a little higher nitro content.I also agree that the os F is the plug for all 4 strokers, but have heard good things about the new YS plug.
Cuda

same here except when i bought mine the guy at my lhs told me i'd better get the os plug.never had a problem.ran great right out of the box.breakin wasn't a big deal either.

good luck
glenn

Also try replacing the needle valve O-ring if all else fails. I have a Magnum .61 FS that will change mixture setting at my fingers' slightest touch of the needle. Changed the O-ring, and problem gone.