twazz

My Feedback: (2)

I have an OS 61 fx w/pump on a Sig Astro Hog. The problem I am having is when I throttle up a lot of air bubbles start flowing in the line from the pump to the carb and kill the engine. I have tried various needle valve settings, have changed out all fuel lines, and have changed out the fuel tank. Please Help!

Rickles56

Must be an air leak on the tank, the fuel line to the pump or the pump itself is leaking air. If not that, then the fuel is foaming up from vibration. Try putting some foam rubber under the tank. If it is touching the fuse formers or other solid area of the fuse all the engine vibrations will be transfered to the tank and the fuel foams up. You can get a brass filter clunk that will filter the air. You should also have a filter inline before the pump, get a filter that will stop air bubbles but make sure it isn't foaming first.

twazz

My Feedback: (2)

Thank you for the information...I will give that a try. To the question...B17's is there anything else...the answer is NO. My grandfather was the belly gunner in a B-17 over Germany. He was shot down, ended up in a prison camp, and eventually freed.

Rickles56

I have a "thing" for B17's, since I was a kid even. I still have plastic models of them. I can sit and listen to the stories former crew members talk about them all day long. The 390th Memorial Museum at Pima Air and Space here in Tucson is manned by ex-B17 crew when they are available. It's always a treat to listen to the stories of the heroism all those guys had. The odds they faced were huge but they always went on the missions.

Hope you get your air bubbles issue fixed!

Bax

My Feedback: (11)

The O.S. Max .61 FX doesn't come with a pump. If you are getting air between the pump and engine, then you have an air leak somewhere in the fuel system upstream of the pump. You may also be getting vibration-induced fuel foaming, which allows the micro-bubble to collect and make bigger ones in the pump.

Your pump may also be bad, and allow air to get into the fuel.