Originally Posted by franchi

Hi All:

When I got my MVVS D7 running as it should, things went to Hell in the air.

I adjusted the engine to what I though was a great setting and launched the plane. The thing ran like a sewing machine for I/2 tank and then became grosslyover compressed to a point where I decided to dump it to save the engine from potential damage. The second flight was the same story. The third time that I fired up the engine, I pointed the straight up while holding the plane. The engine went over compressed as it did in the air. I have no thoughts as to why this would happen!

The engine runs great on a test stand with almost no exhaust residue, very light yellow, and very little smoke.

The plane is a Tom Tom with built in tank, I will return to the test stand tomorrow to see how well the engine runs. If it runs well on the test stand, I will attach a profile tank on the outside of the fuselage to see if this makes a difference. I have seen this done before where the owner did not wish to dig the fuel tank out of the fuselage.

I pitted for my mate's Ollie .15 today and it ran very well. I also had great luck with my OS .40 with a Davis head.

I still think that I need a correct con rod with a bit of offset on the larger end.

Suggestions and/or comments?

Best wishes,

Franchi