I am having problems with a k/b engine.

I have fiddled around with the high and low end needle settings for 30 minutes. The closest I can get to getting this engine running properly is with the low end needle valve turned in as far as it will go. Even then it acts rich. For example When I go from full throttle to idle it takes 30 seconds to slow down When I go from idle to full power it gurgles and spits. If I turn the low end needle out at all the engine will stop as soon as I remove the glow battery. What could it be.

Here's my setup.
Byron fuel with 10% nitro
brand new K&B1L Glow plug
APC 10x5 prop

Engine is a Has K/B inscribed in the carb and it is a 40 sized engine. Thanks

Start over!

Set your low speed (If it's in the center of the throttle arm?) out flush with the throttle arm retainer nut.

Set the high speed about 3-1/2 turns out.

Start your engine and adjust the high speed

Then make another attempt at the low speed.


Enjoy,

Jim

did that. The only way I can even keep it idling without a glow battery is with the low end all the way in. That setting is way too rich. Doesn't idle down.

There must be something damaged about your low speed screw? This carb is no longer used. You might look at the Mecoa site and then over into K/B and then parts. See what parts they still have?

Jim

I would try a Fox or K&B idle bar plug or put a Perry on it & stop your troubles. MAX H.

A perry? What do you mean? Where would I find one for a K&B?
I have the K&B with the old square carb.

If it takes 30 seconds to slow down to idle you engine is drawing air from somewhere in a BIG way...

Try www.conleyprecision.com K&B's have a old & new style so you will need to measure venturi . Also check with Bill Robison he is up on these old girls . MAX H.

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..