hi guys
I have a problem with my engine(ahf 50 3d heli) when Every time I use my heli its good but for next ride my engine getting struck and Iam lubricating it with oil every time .
I am using rapicon fuel
 Is it a problem with fuel are I should take any precaution after the every ride?

How long between flying sessions ?

What oil do you use for after-run lubrication ?  And what quantity ?

How to do you get it to be "un-stuck" ?

Basically, Rapicon seems to have a rust inhibitor, so you should not need additional after-run, unless you are storing it for long term (months).  It could very well be the "oil" you  are using as after-run that is causing the problem.

thanx for the replay
iam using normal bike engine oil
iam opening the engine and putting oil in it and so it gets free
its getting stuck for next ride ......
iam flying for 15 min ,i dont know any precaution after fly....will ther be any? if so plz tell me
should i remove the fuel pipe from corb?

You have not made it clear "how long between flights" you take.  Do you fly every week ?

Also, do you mean that engine gets stuck between two flights, even if you fly twice in a single flying session (on the same day) ?  Sorry, but your description of the whole thing is pretty confusing.

For brands like Rapicon, if you fly every week, there should not be any need for additional maintenance (like putting of after run oil etc).  If anything, just clear out the engine at the end of any flying session/day, by running the starter once after the last flight with the fuel intake closed.  The engine should remain free for the next flying session/week.

If you insist of after-run oil, the trick is to out in a few drops and whirr the engine once with the starter. Use ordinary Singer Machine Oil.

sry for my last mesg
ohk the thing is my engine is getting struck for every flight
i mean yesterday i had tried but it havent worked so put some oil ,it got loosen and started well and my flight is good
but when i try to start today it again got struck 
i didnot removed the fuel pipe from corb is it the problem?

i suppose it is a case of " FLOODED ENGINE".......

next time after flying empty ur tank before taking it home.. and post result

The issue is still unclear.  As Vishwa said, one possibility is that the chamber is getting flooded with fuel. In that case, you only need to open the plug and turn once with the starter, and the excess fuel will drain out through the plug hole. You can also hold the heli so that the engine is on top and the exhaust/muffler is directly underneath, and try to turn by hand, the excess fuel should drain out through the exhaust (which is a bit difficult on some helis, as you have to turn the clutch shoe area).

The bigger question in that case is, why does it get flooded after every flight.  So what we need to focus on is, how do you stop the engine after flying ? 

And do you close the fuel line going into the carb when you re-fuel ?

i will stop my engine by closing the muffler hole 
and as u said in my muffler ther is lot of oil being inside ,its comming out when i put my heli upword( ie the tail part is downword to ground)
thanq guys for helping me with this 

i havent tried to stop the engine by cutting the fuel pipe,so i will try that and see wat happens next
i think as u both said the oil is being in chamber so the piston is not turning....thanq for this help
and where comes to fuel filling. i will fill my tank by removing the corb pipe and i will fill it up

u have a issue in shutting ur engine off...

when u close the muffler exhaust... u stopt the exhaust and the engine stops... but on the same time u are adding more pressure in ur tank through the pressure feed.. hence the engine gets flooded up.

stop the engine by pinching the fuel tube and empty the fuel tank.... u will have no problem..

thanq vishwa...

The right thing to do is to program "Throttle Cut" on your radio, which is tied to a switch.  Then flicking the switch would close the carb completely, there by shutting down the engine.

thanq anwar