MVVS .91 break in
 

I have this engine and have put close to 2 gallons of fuel through it, it runs well on 0% nitro fuel
and 20% oil 10% castor. I just have one problem I still can't lean it out, running a 14x 8 wood prop I only get 8200 rpms if I lean it any further and lift the nose it shuts off. can I expect more from the engine. It is putting out lot of smoke still. Will it get better?


Jeff

RE: MVVS .91 break in
 

Jeff,


This engine should be capable of significantly more than that RPM on the first break-in tank.

It actually needs no more than 500 cc of fuel to be fully usable, after break-in.

And as to break-in, it must be done as described [link=http://www.rcuniverse.com/forum/m_1850473/tm.htm]here[/link].


Please check that the cylinder sleeve in the engine is perfectly aligned with the intake bypasses and the exhaust port.

Although MVVS engine are made from tough materials and gain RPM significantly (400-600 RPM) within 6-10 hours, it is not what I expect for your engine, with the current RPM.

With the MVVS #3250 pipe, on an APC 14x8, this engine should show 9,700-9,900 RPM and even with the #3255 muffler, or #3267 Pitts, it should show more than 9,000.

I believe something is not completely right with this engine, unless it is a VERY heavy 14x8.

RE: MVVS .91 break in
 

Hi
I am about to break in my MVVS 91 in a Pattern plane. The people I bought it frm ( Just engines) recommend running it in with a conventional exhaust rather than the tuned pipe I will fly it with. In the break in thread you link to it suggests using fule with 25% oil in it. Do you make up the balance with Methanol or can you use nitro?

M

RE: MVVS .91 break in
 

Mike,


Paul and Jenny are right!

Break-in is much easier to perform with a normal muffler.


Install the pipe later.

RE: MVVS .91 break in
 

Hi
Okay I had already figured out the common sense in using the normal exhaust. The fuel I sue should it be 25% Castor and 75 Methanol or do I need to make up something else.

Mike

RE: MVVS .91 break in
 

Mike,


That's a good mix for break-in.
Adding 5% nitro will not hurt anything, though.