Hi again,

The manual for my OS 91SII recommends a 14x7 prop for scale models. I'll probably get that or maybe a 14x8 for my GP Spacewalker. Sound right? And what prop have you used to break in your OS 91SII?

I guess I should be in the engine forum with this. But while I'm at it, the manual states that the carb is adjusted at the factory with fuel containing 20% lubricant and 10% nitro. Should I stay with that? I've been using 18/15 Wildcat on my other OS four strokes.

I run my spacewalker/os91fsII with 10% wildcat fuel and a 14x6 prop. Perfect for me.

I use a Master Airscrew 14x6 on mine, I also have an O.S. 91 surpass. I use Wildcat 2-4 stroke fuel with 15% nitro. Seems to work just right.

I'm using a 14x6 with 10% nitro PowerMaster fuel on the OS 91

Thanks guys. Three 14x6's in a row. I brought home a 14x8 Master Airscrew from the LHS today. I guess I'll try it. As I said above, I've been using Wildcat 15% nitro (18% oil). I've been running an OS 70 and 52 with it, and haven't had any problems. I guess I'll stick with that.

Do any of you recall what prop you used break for in? (If you got your engine new.) Did you use your 14x6?

Go with the guys , the 14x6 is perfect. If you go with the x7 or x8 you will not do those perfect landings the SW is famous for.
You can break it with the 14x6 , if you want to be extra carefull use a 13x6 for the first few tanks but not really necessary. If you really love your SW do the run in on a test stand.......

Thanks kqtob,

I definitely will put it on a stand. Sounds like I'll need a 14X6.