4 stroke from 2 stroke fuel
 

I've been running PowerMaster for several years now in my 2 strokes. I like it fine. The past year I have aquired my first 4 stroke engines and love them. But the LHS sells the YS 20/20 blend and it is pricey stuff. Can I just by the 2 stroke stuff, 10% nitro, 18% oil and then add some caster to bring the oil content up to the recommended 20%? And if so, where do I buy caster oil?

RE: 4 stroke from 2 stroke fuel
 

You should not have any problem using regular 2 stroke fuel. That's all I ever use and only 10% nitro. Cool power or Byrons.Been doing so for many years.

RE: 4 stroke from 2 stroke fuel
 

Yes, you can use your 2-stroke fuel with no problem. If you want to run extra castor for break-in, that's fine, but you don't need to add lube for general use. The 20/20 is usually reserved for YS engines that require all synthetic and like the high nitro content. Don't need to spend so much money on other brands of engines, they do fine on castor/syn blends.

RE: 4 stroke from 2 stroke fuel
 

I prefer 15% nitro in my 4-strokes, but aside from that I don't use anything special.

RE: 4 stroke from 2 stroke fuel
 

You said 4 stroke and then mentioned YS 20/20 fuel. IF your 4 stroke is a YS engine, then I wouldn't use any castor in it, as I simply don't like castor in my YS engines. It can gum up the regulator. If your 4 stroke is any other brand then adding castor probably isn't necessary, but then won't hurt anything either. I'm like Minn Flyer, I like 15% for my 4 strokes.

RE: 4 stroke from 2 stroke fuel
 

The nitro can be anything you like but I have been using Power Master 15/18 for everything. You don't need to be adding any oil unless you buy a brand that has less then the 18%. Power Master just calls there 20/20 YS because at one point YS stated 20/20 for there fuel. I mostly run YS and the PM 15% works just fine. When I had to buy Wild Cat it was a 15/16 blend so I added two ounces of Klotz oil to the gallon just to be on the safe side. Smoked a bit more but the engines were OK with it.

RE: 4 stroke from 2 stroke fuel
 

Like others here, I use 2 stroke fuel with added oil. I use 15% nitro because I'm at high altitude but 10% nitro is fine. I bring all fuel up to 20% total oil with castor oil because I like clear pink oil on my paper towels when I clean up. Somehow, that results in engines lasting decades without any rebuilds. I use Sig castor oil which is available at some LHS or the top grade pharmaceutical (medicinal) stuff that is 100% castor oil with no additives.

RE: 4 stroke from 2 stroke fuel
 

I have read that you don't want to run castor oil in a 4 stroke as the castor burns on (the carmel color) it effects the tolerances in the valves.....

RE: 4 stroke from 2 stroke fuel
 

I run Coolpower 15% in everythign whether it is 2-stroke, 4-stroke, YS, OS or whatever and have had zero problems.

Iliek the 15% in 4-strokes but I have ran them on 10%. There is a little bit of power loss and you have to be a little more careful about the idle mixture but most will run on it.

RE: 4 stroke from 2 stroke fuel
 

Yeah, I've read that too. But my experience shows otherwise.

RE: 4 stroke from 2 stroke fuel
 

It doesn't effect the valves or any of the tolerances. Over time you will be able to see a build up on the valve stem if you look inside the exhaust port. It takes a long time though and effects nothing. When it's time for a rebuild you can clean this off but it's not on any of the seating area. Castor just leaves that nasty looking burnt on coating all over your muffler and any other part that tends to heat up enough to burn it. I saw 42 mention that Castor gums up the regulator diaphragm in a YS engine, this can happen if you leave the engine setting around too long. I have had it happen on one engine but my planes get flown all year long so it isn't too big of a problem. The fix was to just open up the regulator and clean it.

RE: 4 stroke from 2 stroke fuel
 

My LHS sells PowerMaster 15% with 18% oil. Lets say I wanted to add another 2.5 oz. of oil to the gallon to bring it closer to 20% oil content, what kind of oil should I use? How do you mix it in? Dump it in and shake the can?

thnx

RE: 4 stroke from 2 stroke fuel
 

At 18% you don't need to add oil. If for some reason you can't fight the urge you can add about 2 ounces of Castor or I use Klotz. Klots is a blended oil of synthetics and 20% of the blend is Castor. I only add extra oil when I can only get Wild Cat 15% and that has only 16% blended oil. I used the WC during the shift in the sale of Power Master but now that PM is being sold again through Hobby People I'm back to using it again. I'm still running a YS 1.10 that I bought new when they first came out, that was about 10 years ago. I have run the engine twice a week about 4 flights a day on PM 15% and the engine runs and looks like new. Other then the year I wasn't able to get the Power master that was the only fuel run in this engine. Adding oil when you don't need to is just a waste but if you want a thicker smoke trail then by all means, go ahead and add.

RE: 4 stroke from 2 stroke fuel
 

If you do decide to add some oil just dump it in, shake it up and let it sit a while then one more good shake. High shear mixing is not needed to add just 1-2% oil.

RE: 4 stroke from 2 stroke fuel
 

I like the way you keep things simple.

By the way, I'm in full agreement. I use a 15% with a castor blend.

RE: 4 stroke from 2 stroke fuel
 

Same here...Cool Power 15% in all my 2 and 4's and they run perfectly with zero issues.

RE: 4 stroke from 2 stroke fuel
 

coolpower heli 15% here, 0 problems.