I have aquired a used Thunder Tiger .61 pro. For some reason it will not pick fuel up. I've cleaned it and everything and can't get it to pick fuel up on its own w/out priming it. Once it loses its prime it dies. There are no obstructions in the carb and it has excellent compression. Any ideas?

Check all your fuel lines for holes or cracks. Check your tank for the same. Is the carberator sealed where it meets the crankcase? Is there any dirt or stuff in the needle valve assembly? Good Luck, Dave

Disregard.

What is it mounted on, test stand, airplane or what? How are you priming it?
You are sucking air somewhere. Assuming the tank is airtight and hooked up correctly
the first thing I would do is change the fuel lines, the next thing is to check that the carb is seated firmly onto the engine and locked down tight, next check the o-ring on the needle valve and make sure it is providing a good seal.


Regards,
doubledee

Be sure your low speed is not too lean, blocking the fuel feed tube in the throat of the carb.

Rule #1 Never assume anything!

Rule #2 Go over the basics.
- Is the muffler tight?
- Is the Back preassure line attached and free of holes?
- Are all of the lines attached and run properly?
- Are the lines free of holes and securely attached to the fuel tank and nipples?
- Is the Fuel tank stopper tightened down?
- Has the tank been pressure tested?
- Is the Clunk in place with no bends?
- Is the tank mounted properly (even with or slightly abouve the carburator)?
- How long is the fuel line from the Tank to the Engine? Anything over 6" and a pump may be required?

Once you can confirm all of the above - then you can look at the engine for leaks etc.

All good suggestions. I would first, after checking for a tight fuel system (no air leaks) set carb barrel to the just closed position. Close main needle and then close idle needle until it just stops. DONOT use any force. Turn idle needle out 1 1/2 turns. Turn main needle out 1 3/4 to 2 turns. With no glow on open throttle just a little and put a finger over exhaust and crank engine. You should get fuel up to carb by doing this. If you get fuel to carb, try staring engine ( glow power on). If you donot get fuel I would think you have an obstruction in the main needle body. If so clean needle body and try again. Good luck. I have three TT Pro .61s and all run great.