Magnum 52 4 stroke engines

My father has a Magnum .52FS and I have a Magnum .91FS and they both run like champs at all times. His seems to be lacking in compression in his opinion but it runs great so its not a big issue. I have an OS .52 that has a lot of compression and runs about the same so go figure. I would check your adjustments both high and low end mixtures.

Maybe change teh glow plug? If it is the same one used for break in it muight be shot.

I have a magnum 53 4 stroke and never had a minutes trouble with it. Idles perfect and runs great. I run it on 30% heli fuel. Have it on a Dazzler. Eddie Fulmer AMA 63713

My Magnum 52 FS runs great. I use OS F plug. I did try a thunderbolt and could not get it to idle. Also, I did notice a power loss after about 1 gallon. Valve adjustment cleared that up. I think I do need to change o-ring on low end needle. It seems to move too easy. I also put a piece of large fuel tube on the high needle but, I do this with most all motors.

You might want to check the valve clearance. I think it should be

Greg

snip, HI All, One thing I have found with four strokes is not to give it a compression test with the throttle closed. It will have very little because it has not sucked in any air; Only has air that it can get from the crank case. Check it out. Happy flying, Gene

Some folks, including me, have noticed that the high speed needle is a loose fit and if you touch the needle while the engine is running you will notice a large drop in rpm. If you find this is the case replace the O ring with a better fitting O ring, or what I did was add a second O ring to stabilize the needle valve.

Ed

George and Jo Jenn> I have several of these. Sraet easy have lots of power but after about a

This same problem is covered in this months RCM magazine. See the engine clinic column by Clearance Lee.

Have you tried adjusting the valves yet? Also have you tried a new glow plug. After break in, both of those will need attention.