Having a problem with this combo recently. After the fuel tank reaches around half full (or half empty for you pessimists) hard up elevator manuevers cause the engine to die. Full down elevator either inverted or not is no problem. Only upright level flight at half throttle or above and then pulling hard up elevator. When the tank is full, it does not do this. The only thing I can think of is the high G force is cutting off fuel supply but I would think the pressure from the Saito's muffler into the vent tube would keep that from happening. I figured I would field this one to you experts out there. Thanks for any input.


On a positive note, I have probably logged a lifetime of deadstick landings...Twist always floats in perfectly

Jerry

It's conceivable that the high "G" is pulling the fuel back into the tank so strongly that the muffler pressure is unable to overcome it.

In your shoes I would immediately switch to a Uniflow setup which is almost trivial to do.

This should help immensely.

Maybe you should take the fuel tank apart and look for a pin hole in one of the lines !! ENJOY !!! RED

How would a pin hole factor in?

Wouldn't the effect of a leak be somewhat consistent at all attitudes?

He only reports fuel starvation during hard up elevator with half a tank.

After taking the whole front of the plane apart I found that the vent tube inside the tank had turned 90 degrees and was no longer pointing towards the top of the tank but to the side of the tank. I could find no other issues with the setup. Could this be the culprit?

Yes. Same thing happened to me once. I corrected the vent tube and problems went away.

Bingo. Problem solved. Ran three tanks through it with no issues. I still don't know how the vent tube rotated 90 degrees. Thanks for all the advice.