Ok got a brand new trainer with a megatech m46 engine. Filled it up and started the bad boy. Ran for about 15 seconds and when I removed the glow igniter the engine quit. AFter a few more unsuccessful tries to start up the engine the next thing i know is the piston has jammed up and when the piston is all the way on the top (compression stage) it becomes almost impossible to continue the cycle.

So i removed the glow plug and put in two or three drops of fuel to lubricate it. And it became a bit smoother. Then I hook up my electric starter and after three or four spins the the piston jams up again. But this time it's not that badly jammed up like the first time but it dosen't allow the electric started to move it. So before trying anything else I thought I would post here for help.

Thanx.


(*Forgot to add this earlier*)

-During the first time when it ran for 15 seconds there was no smoke whatsoever (muffler blocked ??)

-When I turn the turn the prop in the opposite direction the carb spits fuel out (normal ?)

-Some bubbles in the fuel line (I heard that's bad : so how do i get rid of it ?)

If you remove your glow plug, does it spin freely?

not all that freely as it gets a little tight when the piston is completely up.

Plus some things i forgot to add.

-During the first time when it ran for 15 seconds there was no smoke whatsoever (muffler blocked ??)

-When I turn the turn the prop in the opposite direction the carb spits fuel out (normal ?)

-Some bubbles in the fuel line (I heard that's bad : so how do i get rid of it ?)

Is the tanke higher than the carb? That may flood the engine.

ABC engine tend to be real tight at TDC when new. This will get better as it breaks in. Try removing the plug and running it with the starter a bit.

It sounds like it is real rich. Try it at the factory needle setting.

I have seen ABC engines that are unbelievebly tight when new. A weak starter may not be able to turn it. Use a chicken stick.

Keep trying it. It should get better. Just be sure to not let it flood and locak due to too much fuel.

The above advice is basically sound. I would recommend that you do remove the plug then turn the engine over by hand. When you get the piston stuck or at TDC, move it gently back and forth and see if you feel any slop. If it is tight, with no play, then I would recommend that you start the engine and run it for the full tank alternating from max RPM to super rich and gurgling just using the mixture screw. You may want to do this twice but after the second time, set the engine to max rpm then back off 300 rpm by making the engine rich then fly the plane!

One thing you may check is if the washer is on the glow plug. If so, maybe you can get an extra head gasket, run it with the extra gasket until the engine is broken in, then go to one gasket!!
Just a suggestion!

Tom

thanx for your advice people.

i will try removing the glow plug and turning it around..

Tom : THere is a washer on the glow plug

Another thing is that I removed the glow plug and connected it to the igniter and when it turns orange it makes a hisssss sound.. is that normal ?

Yes, the hissing sounds if the fuel being burned away from the coil.

As stated, if it is seizing, you are getting too much fuel in it. Make sure the tank isn't letting fuel flow in when it is just sitting. I have one plane that does that. Keep the tail low till you are ready to start it.

You could also seek help from the guys at your local flying field and they can show you how to start it. If you get too mucy fuel in it and spin it with the starter, you can bend the rod. Not a good thing.

Sounds like this is your first engine. I would seek help with it. Save the engine and the plane if they help fly it too.

ok i don't know what the problem was but i reset the needle valve settings again and changed the battery in the glow igniter which didn't make much of a difference and voila it started ..

Ran half a tank and it's still real hard at the compression stage.

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Anyways another question i had was at idle the plane shouldn't move and should stand still.. Let me know if Iam right coz at the lowest point the plane moves so i gotta make a little throttle settings.

Has any one thought of ABC have no rings. After broke in it will free up a tapered cylinder make compression. After a few tanks of fuel it can be idled down!

also, try putting on a second washer on the glow plug and running it a bit. Also, set the tank level with the carb because what can happen is fuel is being forced into the carb by backpressure and gravity, basically flooding the engine. when you turn the prop backwards it spits out the fuel because there is way too much inside. If it is really hard to bring the piston back down from tdc rotating it in the normal opperating direction, that again points to too much fuel. Two strokes have a fuel system where when the piston is moving up, it draws fuel in through the carb. when it reaches tdc, the intake closes, meaning that on the downstroke, it is compressing the fuel air mixture, so that when the piston reaches bottom, the exhaust can only go one way because of the force of the fresh mixture coming in.

ABC-type engines are very tight at top dead center when new. It's important not to just turn them over to feel how tight they are. In some cases you can break or damage the engine by doing that. It'll be tight with or without the glow plug installed.

Thanx for your help guys.. I appreciate it