hi i have a little control line airplane and it has a Cox single piston engine on it. And for the last 3 hours iv been trying to get it to start and it refuses to. It was running fine yesterday after i had to mess with it for about an hour. its still new..iv only had the plane since December. and i havent flown it more then 20 times. Can anyone give me suggestions as to how to fix this problem? Iv tried everything i can. Thanks
Fox

Is the element in the head still good? Did you run it lean and burn it out on the last flight? What engine is it? [8D]

the element in the head thill glows...exept for the top ..umm..2 or 3 milimeters (about half a turn dont glow) what do you mean by lean and burn out? And its a Cox Sure start .049. But it sure dont start. lol
Fox

We could tell you more if you could tell us how it doesn't run. You may need a new glow head. Cox engines start and run best if the glow plug really lights up. There is a copper gasket between the head and the cylinder; If not, get one and put it in. Check your needle valve. Sometimes the tip of the needle will break off from vibration. If so you need a new needle and need to get the broken tip out. Another possibility is that the reed valve which lets fuel and air into the back of the engine is stuck or has a piece of dirt in it. Check and see if the back plate is on tight. It may have vibrated loose enough to cause a leak in the crankcase.

All of the above are easily fixed. The connecting rod joins the piston in a ball and socket joint. This joint will loosen with time, and left alone long enough the rod will beat through the top of the piston (speaking from experience here). I imagine your rod needs to be reset. Carefully turn the propeller until the piston is at the top of the cylinder. Now gently wriggle the prop back and forth a little. If you can wiggle it much with the piston staying in place, the piston needs resetting. Cox makes a tool for this, but if you can find someone who knows about engines to help you, best do so. It is easy to ruin the piston trying to reset it (experience again).

Hope this helps.

Jim

hmm..how it runs... Basically it just refuses to start or act like its starting or anything for a long time. Then itll start and run and from then on itll start everytime. But it takes atleast a hour befor it gets to that stage. im not sure if that helps or not..

I think i found the problem! i took it apart and the anchors for the exhaust pipe (i believe it is) were boken on the bottem corners. Is that posibly what is making it not start? or maybe its the air intake..i dont know. im not an engine person hehe. But if i superglued it back together (considering its just plastic) do you think itll fly..atleast till i get a new engine? This is a really cheap model so its not like its going to kill me if it wrecks. In fact. the whole front nose is broke where it nose dived and the engine came out the front. (i dont know what happened...it just after takeoff, went strait up and strait down) Anyhow reply if anyone knows what im talking about..