Ok you mvvs experts, here is the problem. I have a new mvvs and looks like a real sweet engine, well made. I put 15 minutes on her as specified in the manual for a break in. The idle is great as well as the top end. Transistion is good as well. I put two 8 minute flights on her on a ddust. This engine has a mini tune pipe. The problem is if one keeps her at 1/2 throttle for 15 seconds or longer then guns her she will quit, a rich mid section. Again top end seems fine as well as the bottom, it does not load up on the bottom end. Could it be it needs a little longer running time on her?. The only other thing is the the neoprene coupler between the pipe and header is about 3/4 on in inch, could this be too long, or is the stock header too long?

Thanks in advance
Peter.

MVVS engines are pretty tight when they come from the factory. I think that 15 minutes run-in time is pretty optimistic.
I've sometimes had glow plugs do strange things like this, but I wouldn't get too excited until the engine gets a couple hours
run time on it. Ross

Hi!
Being the Swedish MVVS distributer since 1992 I can say that MVVS engines doesn't need any lengthy running in time, just run a tank on the ground and then set the carb...and go flying. Fly it a little rich leaning it out tank by tank for the next 5-10 tanks.
When you can't give power without the engine quiting from half throttle, the idle needle has to be set. It is either set to rich or too lean.
It the engine stops instantly when you give power ...the idle needle is set to lean.
If on the other hand the engine blubbers and spits fuel ...the engine is running too rich.

The new MVVS carb is a wast improvement over the old one, so if you have the old carb with a idle needle with a thick blunt tip, I recommend getting the new carb or either get the new idle needle kit that is a replacement for older carbs.
Regards!
Jan K
Airracing products
http://hem.passagen.se/airracing

Thanks Guy's

I had run two tanks on the ground for a break in and then two in tbe air, so it has over 30 min. on it. I have lots of engines and have no prob. setting any of them up. With the rich mid section, I had thought it might have something to do with the mini pipe. I'll run her some more and see if the matter clears up. I don't know if it's an old style carb. I just purchased it and it has the blue head, sure is pretty

Peter