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Engine basics => Engine set up tips => Topic started by: Bill Hodges on February 17, 2006, 08:18:34 AM

Title: OS Max 20
Post by: Bill Hodges on February 17, 2006, 08:18:34 AM

I have an old OS Max 20 that I mounted on our club trainer.  It is not the FP.  Could someone enlighten me on what fuel to use in this engine?

Bill Hodges

Title: Re: OS Max 20
Post by: RandySmith on February 17, 2006, 09:26:11 AM

HI Bill

If you get SIG fuel, the 25% castor  would work well in that engine

Randy

Title: Re: OS Max 20
Post by: Bill Hodges on February 17, 2006, 12:51:22 PM

Thanks Randy.  I just happen to have a couple of gallons in the shop.

Bill

Title: Re: OS Max 20
Post by: Chris Gilbert IRL-1638 on March 06, 2006, 06:45:02 AM

Hi Guys,

I dug an OS max 20 out of my attic, but I've no idea as to what propeller to put on it.
First flight was 9x4, followed by a 9x6, with disasterous consequences (more firewood)

Any advice?

Title: Re: OS Max 20
Post by: Steve Helmick on March 06, 2006, 11:39:32 PM

Most .19-.25's run happily on a 9-4. I'd suggest trying APC, Taipan and Graupner "GRP" props. "GRP" stands for Glass Reinforced Plastic. The fiberglass makes them stiffer, more efficient, and more brittle. But they hold up a lot better than wood props to grass fields, and are generally pretty consistent from sample to sample.  8) Steve

Title: Re: OS Max 20
Post by: Chris Gilbert IRL-1638 on March 07, 2006, 12:31:37 PM

Thanks guys. Will have to add some 9x4s to my next shopping list.