OMP yak engine and prop question
 

I used to fly a OMP yak 65 with a 91fx engine. The prop was an APC 15x4w. Now this engine is damaged and I am replacing it with an OS 91 four stroke that I had laying around. Whats the equivalent prop for this engine for similar performace? I would not mind buuying a new engine whats recommended in the new 2 strokes? Perhaps a 120AX? Not been flying glow for almost 2 years so little out of touch with it.

RE: OMP yak engine and prop question
 

The 91 4S would be a little weak on the 65 yak but the new 120 ax would be the ultimate ticket! I have my eye on a 120 ax myself. As for props on the 91 4s I'm not sure but would guess maybe a 14-4 to 14-6 might be good.

RE: OMP yak engine and prop question
 

Mike whats the recommended prop for the 120AX?

RE: OMP yak engine and prop question
 

i was wondering the same thing. i just ordered the O.S. 120AX of my new yak 65 arf and im not sure what prop would yank this plane around really nice for some sick 3D.

RE: OMP yak engine and prop question
 

Believe it or not the new 120 AX will swing a 17-6 with authority. That's what I'm using on my setup. Huge difference from the .91 FX.

RE: OMP yak engine and prop question
 

Mike, what prop would you use on the Yak with a YS 110? How dose the OS 120 compair to the YS 110 for 3D?

RE: OMP yak engine and prop question
 

I use a 16-4W with 20% fuel on my YS 110 and Fusion combination. I get instant throttle response with this setup. Many folks also use the 16-6 with the YS 110 and like that combo a lot as well. Many of those folks do run 30% nitro as well. Hard to compare but I'd say the OS has more total thrust but the YS has faster throttle response.

RE: OMP yak engine and prop question
 

AFSalmon, I read on an earlier post you were using a 17-6 with the O.S. 120ax. Have you changed or was this a typo. I'm fixing to order some props for my 120ax Yak combo.

RE: OMP yak engine and prop question
 

You are correct! I did make a typo above and just corrected that. I use the APC 17-6 prop on my OS120 AX. I have found though that a lighter high quality wood prop such as the Vess 17-6 performs much better than the heavier nylon props.

RE: OMP yak engine and prop question
 

Mine flies nicely on an APC 17x6 with a 120 AX. Bags of thrust and a pretty good throttle response. The engine is still new so I am running rich and have yet to play with the slow running settings.

RE: OMP yak engine and prop question
 

ys 110 16x5 30% nitro on my fusion . same thing going on the yak 55 (omp)