Last week I posted some problems about my evolution 40. It seems to have an air leak somewhere and I was going over everything and found NO LEAKS anywhere. All lines are new. All bolts are tight. Tried an old and a new glow plug. RTV'd the carb and back plate. I tore the engine down and checked the bearings. They seemed ok as they were smooth feeling and didn't have any noticeable play. Well tonight I got the engine back together....after RTVing everything and fired her up, hoping that the air leak had been cured. NOPE still acting up!!!!!!!!

I pulled the fuel line that runs between the carb and the needle valve off, and placed my fingers over the venturi and the fuel inlet. Then I gently rocked the piston in and out of compression and heard a sucking sound. Listening carefully I decided that it was coming from the bottom of the carb....or behind the prop. I went and got some soapy water and discovered bubbles were coming out from behind the prop. I HOPE I JUST DISCOVERED MY PROBLEM AND CAN REMEDY THIS!

So engine gurus, Do you think this is my problem? Or is it acceptable to have a little air come out of there? Will a new bearing cure this?

Or are there any other solutions you might have besides the obvious leaky fuel lines or loose bolts?

This engine has gotten on my last nerve and I really only want to have to take this turd apart one more time.

Thanks for all the help!! You guys are awesome.