ORIGINAL: w8ye

Looking down through the thread, there were a couple references to Magnum 52 four strokes not having the power of a 46 two stroke.

I've seen a lot of the Magnum four strokes with less than satisfactory power.

These poor performing ones I've personally looked at had the cam timing advanced one tooth. This gave a great idle but took the engine performance down one prop size.

These engines when the piston at top dead center had the cam timing mark straight up and down. Either 6:00 or 12:00. And this was from the factory!

The proper timing position is in alignment with the push rods. Preferably with the mark dead center with the exhaust cam follower hole.

This is very helpful to me as I just bought a Magnum 52 4-stroke for a Balsa USA 1/6 scale Sopwith pup. It specifies a .40 to .50 4-stroke or a .30 to .40 2-stroke and the plane weighs 6.5 lbs. I've not done much in the past with 4-strokes but it seemed that this engine was a pretty good match for this plane. I printed the picture you guys posted so I have that info but how do you tell when the piston is in the proper position..........TDC as opposed to the exhaust stroke??? I used to work on cars but I'm pretty stupid when it comes to model engines and it's been a long time. I would like to take whatever I have to off the engine and look before I even attempt break-in.......that way I'm starting in the right spot. All help, pictures, etc would be greatly appreciated!!!

Thanks
Andy