I just purchased a Tower Hobbies .75 ABC engine. The Manual recommends castor /synthetic mix. I have 2 gallons of Cool Power 15%, which is all Synthetic. Question... Do I add castor or just run it a bit rich, or give away the 2 gallons and get Omega 15%????
p.s. I use CP MV 15% in my Saitos and they seem to run well. Thanks, Monkey Gutz

Yes, you *can* add some castor.

The problem is that For break-in you probably want to raise the castor level to at least 6%-10% which will mean that your total oil content will increase to 24-28% by volume. This would do for break-in but would be unnecessarily messy and rob you of power for general running.

One thing to consider however is that the 75 is an ABC with quite a bit of pinch and (like all ABCs) should always be run using fuel that has some castor in it.

Yes, some folks do run their ABC engines on fuel with straight synthetic oil -- but those engines won't last as long and are at far more risk of damage from a lean run than engines that have a little castor passing through them.

If I were you, I'd just go out and buy a jug of Omega.

You can buy a pint bottle of Klotz Beno or Sig castor at the hobby shop to add to your cool power to use it up?

If you are just going to do it once or twice, buy some castor oil at wally world or the discount drug store. Usually the drug store stuff costs more if you are going to use it in every gallon of fuel.

Thanks for the quick replies, guys. I called up the LHS ( where I got the fuel) and asked if they had any castor. The answer was maybe in a week or two. I told them what was going on and they said come on down and swap out. So now I have 2 gallons of Omega 15%. Hopefully alll is right with the world now.... Thanks again... Best Regards, Monkey Gutz