Slight Issue

The fuel is clean. The engine was a little crudded with castor when I got it. I cleaned the outside to a nice finish. Has no scratches. It is rather random (it seems) when it does it. Needle valve is not spinning.

What washer and tube are you talking about? Prop washer? Tube on the needle valve?

The tube and washer to seal the NV. It's likely gravity. Or a crankcase leak.
You have bladder supplies, why not feed it with pressure.

That is worth a try. I had been running this engine rather rich. It felt as if it had not been run much. Same for the Hopper. Made me excited. Newest Cox engine I have owned. I need to polish the crank of the Killer Bee. That should really help it along.

Rolla

Like this. It ran like you said until Mr. Rusty put it on there, then it leveled out and wound up. This particular KB has not been run yet.

Godsey3.0 wrote:That is worth a try. I had been running this engine rather rich. It felt as if it had not been run much. Same for the Hopper. Made me excited. Newest Cox engine I have owned. I need to polish the crank of the Killer Bee. That should really help it along.

Rolla

Don't get too carried away with the polishing. That's one of those things for when you're trying to eek out the last bits of hidden horse power. Meticulously balance your props, hubs and all, if you want the most out of your engine.

Are you using an old metal tank, or using brass tubing? Sometimes brass tubing will get a crack that leaks some air. It will run with your setting until the hole is uncovered then draw both air and fuel causing it to lean out as you describe. Copper tubing is better.

Geoge

I'm with Matt re the self adjusting N/v
If you mark the nv (I pinched the top of mine with
A pair of pliers) you'll see it moving at v high revs.
I'd put money on it.
If you look at my tube killer bee you'll see it doing
Just that against the tacho before I realised what was occurring.

It is not the Needle Valve turning. The fact that when I open it up it goes too rich disproves that. Last run I watched it and the NV is not turning. The tank was used on Space Hopper and OS Max 10. Both were fine. I soaked the engine in alcohol. The NV was a little gummy. Space Hopper's NV was frozen. Jeat and fuel barely get it loose.

Side question; on a Tee Dee, are the threads on the outside of the metal venturi or around it? I guess I l should ask does it thread into something or around it.

Thanks a Bunch,
Rolla

P.S. I will try the tubing and washer. Later. Very early right now. Sun has not risen. Chilly outside.