RC-max-mod

I have a Plane fitted with a 40cc Gas engine with electronic ignition and Walbro Carb.
The engine is a few years old and looks well used but has good compression. I dont think it has been used for a while.

The Problem I have is that I can't get it to run for any longer than a few seconds.
If I Choke up the Carb(finger over the air intake) and get the engine wet with fuel, It starts up easily but only runs for a few seconds before dieing.
If I partly close the choke flap after it starts, it runs a little longer.

I thought that it might be some problem with the diaphragm pump maybe? It seems to burn up the fuel thats is alrady in there and the die.

Any help would be most appreciated.

RC Extreme power

My Feedback: (24)

This might help

http://www.rcuniverse.com/forum/m_6399651/tm.htm

Milton

karolh

Seems like the engine only runs until the prime is burnt off indicating no pumping action from the carb. Install an appropriate carb repair kit and a new diaphram and you should be good to go.

Karol

AirWizard

My Feedback: (3)

You might check the low needle and make sure that it is on the rich side to start with/

bob_nj

My Feedback: (62)

I agree with karolh.
I had an engine do exactly what you are describing. I also put a kit in it and it still would only run on the prime.
Long story short, I didn't replace the screen in the kit because the one in the carb "looked" fine.
Turns out it wasn't fine.
The screen was the problem, and after replacing it, the motor ran like a top.

Check it and let me know