cbr954rr

I am training a guy that has a thunder tiger 61 on his plane. He nosed it in the last time we flew and we had to make some minor repairs to it. Since the repairs the motor wont idle below 3000 rpm. It just slowly just drops the idle untill it quits. The repairs were very minor just had to repair around the nose wheel block it busted the firewall so we put a piece of ply behind it and used corner stock to reinforce it. We have tryed to replace the fuel lines including the clunk line in the tank. It is set on the rich side both low and high end but leaning out does not help the problem. We have checked the carb and made sure it was seated. We took the carb and the needle valve out and cleaned them out. It just seems like it starves for fuel. If you put your finger over the exhaust outlet it will stay running for a little while longer. The motor will not draw fuel on its own you have to put your finger over the carb or exhaust to make it pull.

any ideas?

KidVermin

My Feedback: (3)

Don't you just live for little challenges like this ?
You've put in a new plug, right?
The spray bar is located as when new ?
Even though the carb is seated, try some gasket sealer goop. Sounds like you're sucking air somewhere.

bkdavy

My Feedback: (1)

Did you completely disassemble the carb, or just pull out the high speed needle? There might be some small obstruction in the spray nozzle thats causing it to lean out too far at idle. Take it completely apart, clean everything, then try again. I've had planes that did that, and was amazed at how small a piece of dirt or plastic has to be to block the fuel flow at idle.

Trying a new glow plug is also a good idea.

Brad

skiman762

also I would pull the tank apart and check the hoses make sure they didn't get cut where the attach to the tubes
it's amazing what G forces can tear or cut

burgh_guy61

My Feedback: (11)

All good advise listed..one obscure thing i have seen happen that fits right into this is;
Check the nipple on the exhaust to see if it got blocked. Only 2 times i have seen this happen
Once was locktight blocked it the other was dirt somehow blocked it. Just wanted to offer this also
as your describing the exact same symptoms.