I have several of these. Sraet easy have lots of power but after about a gallon of fuel they idle poorly. They die at idle on landing and I can never taxi back to the pits. Have tried many carb settings adjusting both needles. They seem ok on the ground but then die at idle. Are these carbs a litle weak in the O ring area/ Or what?
1) Poor compression 2) Crank bearings got lose after about 1 gal. of fuel. 3) Needle valve leaks fuel and hard to adjust. 4) exhaust and intake valves leak. for $40.00 more I could have bought an OS 52. Sent engine back to Hobby People, Have not received it back yet?
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
0.004" - 0.010". My Magnum 52 runs and idles great, although it seems to have low compression, at least when compared to OS 4-strokes.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.
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