My first YS engine
 

I bought a YS-91-C for sport flying on a Sig Hog Bipe.

I bought an OS-F plug, a Zinger 14X6-10 prop for break-in and a Zinger 15X6-10 for after break-in.

Now for the hard part, what fuel???

I have been reading for some time now many debates over synthetic; castor; synthetic castor combination.

Every engine expert, every fuel expert, and everyone inbetween all have very different opinions of what is best.

The YS manual states 15-20% synthetic or castor or a combination can be used.

What oil do you recomend and at what percent min. / max.

Also is 15% nitro okay for sport flying, I know most people use 20% but I do most of my flying about 1/2 throutle most of the time anyways.

Thanks for any help in this matter,
Tim

My first YS engine
 

Powermaster YS blend 20/20 is the fuel of choice for the YS line. You have the right plug OS-F. Be careful you don’t over rev with a 14x6 prop. That engine can handle a 14x10.

My first YS engine
 

Use a good quality fuel with a minumum of 18% oil, synthetic will work the best since it will keep the motor nice and clean. Castor has a tendancy to gum up in the regulator.

You can use 15% nitro but you will get much better performance from 20%-25%, or even 30%. Prop the motor so you spin 8500-9000 on the ground.

F plug is a good choice. After break in you will likely need to reset the valves.

Enjoy

My first YS engine
 

AV8TOR,

Yes, the YS 20/20 does seem to be the choice of many. I was hoping to find an alternitive that I could buy locally so I would not have to mail order a full case.

As for the prop it is not a 14X6 but a 14X6-10. The pitch is 10 near the hub and tapers to 6 at the tip.

Thanks to both for the replys, I posted in the "YS engines support" hoping to hear from Dave S. on what other fuels he would recomend, if any.

Thanks again,
Tim

My first YS engine
 

YS recommends 20% nitro and 20% oil in all of it's 4 stroke engines. Many of the top fuel manufacturers sell this blend known as YS 20/20. In warmer weather some of the YS engines will do ok on less nitro. Our recommendation is to go easy on any castor oil in the fuel. A couple of percent is OK, but any more is asking for regulator problems. Those of you with corporate funding may want to try 30% Helicopter fuel. Hard on the wallet, but very addictive!!!!

My first YS engine
 

Wonder,
You have the east coasts largest manufacturer of glow fuel near you. Give S&W a call or look in most of the eastern PA hobby shops. His 20/20 is a true 20/20 all synthetic and is an excellent fuel.

http://www.s-whobby.com/prices.html

Fuelman

My first YS engine
 

Dave,
Thanks for the info. I will go with the 20% nitro 20% oil. I am leaning towards 18% synthetic 2% castor.

Fuleman,
Thanks for the web site, I e-mailed them about shipping cost since they are 5 hours away.

:D :D :D
Tim

My first YS engine
 

Dave

I have a new YS63 and have tried everything to start the engine. Do you have any suggestions?

My first YS engine
 

What does the engine do? I need a bit more info. Dave

My first YS engine
 

Dave:
Back to the fuel. I'm using Cool Power 15% 4 stroke fuel and my 91 runs like a dream. Is this good??
Thanks!

My first YS engine
 

If it works for you, that's fine. If you have problems when the weather cools off, raise the nitro content of the fuel.

My first YS engine
 

I run my YS91FZ on 10% nitro (its very expensive stuff in Britain!) and get 9000 revs on an APC 14x10 at absolute peak. Motor is still not run in, had about 7 tanks through it so I back it off a few hundred revs at the moment.

Harry