Holy Grail Carb

[Mark Bullard]

Back in the day the Perry Carb and Pumper work this way by replace the back plate. This was used a lot on ducted fans motors. But not everyone could set one up. Robart came out with a pumper for airplanes that I installed on the first 7.5 outboard I ever built because of where the fuel tank was mounted in a Hotshot. The first run was a very lean motor. So decided the fuel tank was to low and I installed the Robart pumper and the problems when away. Now the barb fitting that when into the back plate was a check valve. I do not know if there still made or not.

 

[John Beardslee]

Back in the day the Perry Carb and Pumper work this way by replace the back plate. This was used a lot on ducted fans motors. But not everyone could set one up. Robart came out with a pumper for airplanes that I installed on the first 7.5 outboard I ever built because of where the fuel tank was mounted in a Hotshot. The first run was a very lean motor. So decided the fuel tank was to low and I installed the Robart pumper and the problems when away. Now the barb fitting that when into the back plate was a check valve. I do not know if there still made or not.

Hi Mark,

My .55 and .91 YS heli engines all run on crankcase pressure with a pump system. They have an inline check valve and the plastic tanks are captured between the frames (carbon) but it still bulges a lot. We use a tee fitting with a pinch clamp to bleed off pressure when we complete a flight.

Thanks, John