Can anyone help me with my MVVS? I bought it because the docs. say that it'll do 17K rpm with about the same hp as my OS .46, but since I got it the best I've been able to do is 14K regardless of prop size.
Is there something I should check or change or should I just accept that this will never be a racer and use it on a fun fly plane?

Thanks for the help

Craig
[email protected]

Is the engine broken in good, are you using fresh fuel with the correct amount of nitro & oil, have you tried a 9X6 apc prop, do you have the correct glow plug installed. A little more info would help to solve the problem, if infact there is one which it seems the rpm is some low.

Is this a standard .40 engine or a .40 Quickie engine. ?

A .40 quickie engine with tuned minipipe should do a 17000 rpm with a 9*7 prop.

bobi

I'm sorry, I should have been more specific and at least told you what engine it was...
It is a .40 GFS-R, front carb side exhaust using stock exhaust.
The fuel I am using is Omega 5% (as recommended). I have tried both an O.S. #3 and #8 plug and a K&B cold plug with no difference. The engine has been broken in and has about 20 - 30 flights on it (at least 2 gallons of fuel).

And love it. Just starting to get with it now as I have 3 flights on it. I broke it in on the ground - about a tank's worth. Mine is still running rich on Omega 5% and APC 10x6 prop. I have the mini-pipe (not that standard silencer) and it easily turns 14,900 rich (300 to 500 rpm off max). I suspect with a bit more run time I will tune it to 15,200 - 15,300 (maybe more) on the ground. It turned a 11x4 APC at 15,300. I suspect it would turn a 9x7 at 15,700 or so. I think the racing version will hit 17k plus, but not this sport version of the engine.

By the way I was testing on a 65 degree day with about 30% humidity. I am at 1,000 ft.

Mines a keeper for sure. It beats all my .46's (when they are on standard silencers).

Mike

Hello!
The MVVS.40 GFS/R engine(6,9mm carb) with standard silencer on a 10x6 APC and 20%castor oil and 0-5% nitro will rew 12700-13200 rpm at sea level using a Rossi 3-4 plug and standard headshim.
On the other hand the same engine using the short
minipipe (there is a long minipipe too)rews apr 16500-17000rpm using a 9x7 or a 9x6,5 APC prop.
The MVVS 6,5cc Q-500 engine( 9mm carb) rews apr 17500rpm on the same propsusing a Rossi 6 glowplug.
If you use the longer minipipe expect more trust at lower rpm (10000-15000 rpm.
If you want low noise, get the super quiet silencer which will also give you better throttle respons.
Better still is to get the new "butterflyvalve carb" from MVVS made for the 3.5cc-8.0cc engines.
MVVS engines are delivered with either a Rossi 3-5 glowplug or a Nova Rossi 5 or 7 or their own cold or warm glowplug. The cold plug are use in the bigger engines (3,5cc and up).
Experience have showed that ENYA 3-4 or OS 8 or a Rossi 3-4 glowplug work best if you run on low nitro contents(0-10%nitro)
So ...what prop do you use? What fuel do you use?

Regards!
Jan Karlsson
Importer of MVVS engines
Sweden