Hey fellas,

Currently running a MVVS .40 on my .40 sized stik and i'm having flutter problems because its just going too fast. Seems like any throttle position past 1/2 and the engine screams with power. Its been tached at 17.5 on the ground. I'm running a 10x4 on the engine because that's what was on it when i bought the plane from a guy getting out.
What prop should i be running to lower my airspeed but maintain my power? I tried the mvvs website, but they don't recommend any props.

Flatspins, I ned a little more information. Is the MVVS .40 A Quickee 500 or a regular MVVS .40? If the engine is a Q500, you can try an APC 9X7 or a 9X8, I prefer the 9X7. Also, APC makes a special pylon prop, 8.75X7.50, which also is very good.

If the engine is a regular .40 I always use an APC 11X4.

Its a Q500 .40. I always thought the higher pitch gave me higher speeds, wouldn't i want to go up in diameter?

What kinds of performance do you get with those 9x7's and 9x8's?

The Q500 engine is not really the best for that type of plane. The Q500 is made for high speed and high RPM's. If you want to slow it down, try a 11X4 or a 12.25X3.75 APC prop.

As for RPM's, I would get about 18K-19K with the pylon props.

Hope this helps.

Hello!
The MVVS Q-500 6,5cc engine is made to rew ...try a APC 9x6,9x7or a 9x6,5 propeller. The 9x8 is a little to large....at least thatīs my experience.On my MVVS Q-500 engine (engines) I get apr 17500 rpm when running 0% nitro fuel and Rossi 6 plug and a 9x7 APC prop.
Using the 9x6 APC I get apr 18500 rpm. This is at sealevel.
All these props give a speed of around 200-220km/h (130mph) using a small (140cm span) Little Toni or Polecat pylonracer at 2,2kg.
Usin a 10x4 is too small prop for hovering,sportflying and racing and just about everything else...if you fly at sealevel!
For hovering manuvers try a APC 12,25x3,75 or a 11x4 or 12x4.
For a trainer, like the Kyosho trainer ....use a 11x6 APC. For a low winged sportairtcraft use a 10x6, 11x5 or a 11x6

Regards!
Jan K
Sweden