Crash:

Check here:

http://www.rcuniverse.com/showthread...00#post1243829

Another fellow with the same engine /carb combination.

The block carb had the largest bore K&B put on the 40s, except for the model 8360 engines with the Perry pump and Perry carb.

But if you can't get it to go no matter what you do, and it does sound like an air leak, you can bush the bore of the carb and make it a lot more tractable with larger props.

Also, I don't know what oil the Byron fuel has, but the ringed K&Bs demand some bean - if the Byron is all synthetic get some Omega 15%. My K&Bs purr happily on it. Or you can try adding 4-5 ounces of castor to your Byron and try it. But the engines also like the 15% nitro. Specially with that big bore carb.

And you might try going to a 10x6 or 11x4 prop.

But as I said in agreement with Rudeboy, it really sounds like an air leak. Pull the carb and check its O-ring, and the backplate gasket. Could be leaking either place.

Or do you see air bubbles in the fuel line? That could lead to an entirely different can of worms.

HTH.

Bill..