Go to www.hobbypeople.net , click on engines, locate the Magnum 52 and you should be able to down load the basic instruction sheet. It will tell you how to adjust valves, do a break in, how to tune the carb, etc.

Also locate a old timer who has some experience with 4C engines. An instructor out at the field may help. Ask for help!

While the 52 may not have much compression, it should have some. If the valves are adjusted correctly, and are moving up and down (could have a broken valve spring for instance), try putting a little oil into the cylinder via the glow plug hole. If the ring is stuck that may free it up.

Also there is an O-ring between the carb and the intake manifold, make sure it is there otherwise you are sucking a lot air into the engine and without fuel it will not fire.

There are lots of things that can prevent the engine from firing. Hard for us to tell what is wrong at such a long distance of the internet. Could be a gummed up needle valve for all we know.

Get help locally.

Cheers,

Chip