I have blue head MVVS 8cc
The needle valve get open during flight.
The prop is balanced. I try to extend the spring and put silicon pipe on the out side of the needle but it's still changed
in flight and made me crazy.
Do someone have this problem? What can be done?
I like what this engine give.

Barkai,


Try putting a piece of silicone fuel line on the outside of the needle housing, so when the needle is at its running position (about 2-2.5 mm open), it will just butt up against it. It should hold in place then.

Put it on dry, not wet with oil.

Thanks
But I did it and this was not good enough

Barkai,


I have seen this once, on one of my customer's engines.

He used a Dremel tool to grind the ends of the spring flat, so the spring presses against the nut and the needle handle surface, with better contact. He also used a length of Teflon pipe tape, to make the needle thread-on with a little effort.


I will send you a PM, later this evening, with details that will enable you to contact him.

Thanks a lot

http://poletovani.webzdarma.cz/speed...%20koleno1.jpg