Betelguese

Hello All,

I have a TT GP-61 and I'm having trouble tuning the engine. I'm using a 11x7 prop and 15% fuel. What's happening is all my adjustments are out of wack. I notice that when I tilt up on full throttle, it'll run for 3-6 seconds (increasing in RPM) then quit. I've started adjusting the screws not knowing what I'm really doing and cannot correct my problem. If anyone has any suggestions or literature it would be greatly appreciated.

XJet

First you need to make sure of the following:

1. the engine fuel system is plumbed correctly.

This means that the fuel line to the carburetor must connect to the pipe that has the clunk (weighted tube) on it inside the tank. Also check that this pipe isn't split inside the tank or it will suck air when you lift the nose.

Check also that the second line from the tank is connected to the pressure nipple on the muffler. If there is a third line from the tank, make sure it's plugged and airtight.

2. make sure the engine is tuned properly.

Open the main needle valve half a turn from its current setting and start the motor. If you raise the nose then the engine should pick up some RPMs but not stop. Adjust the needle (with the nose elevated) so that the RPMs reach a peak, then open it again just one click.


Tell us how that works for you.

pe reivers

to add to Xjet:
check the pressure nipple on the muffler. It should be connected to the tank vent, and it should be OPEN., not clogged.
The tank fill line should be plugged off with engine running.

XJet

Keep an eye on the fuel line when you hold the model nose-up. Are there air-bubbles in the line?

estradajae

I'm not sure if you mean is that you don't know how to adjust the engine properly?

did you just started to turn the needle valves trying to guess how it works??

If it's that, you need is a instruction on how to tune your engine....or you meant anything different?