ftjets

I was advised to add the provided head shims on my OS 91 SZ-H hyper w/pump when using 30% nitro. I forgot and have already installed the engine. Should i remove the engine and install them? I probably know what the answer is but you know i had to ask. [&o]

BarracudaHockey

My Feedback: (11)

With 30 percent, I would or you risk pre-ignition, which in the long run will be harder to fix than dropping the engine and sticking a shim in there.

ftjets

Roger that. Somehow i knew that would be the answer but i had to ask. Thanks for the advice. On the other hand, one hobby shop only had 30%. If i was able to find 15%, would i be safe? I will be doing much hovering and basic forward flight for awhile. I really don't need max power. Or should i just bite the bullet and get it over with?

BarracudaHockey

My Feedback: (11)

15's fine the way it is but make sure its heli fuel or has atleast 18 percent oil.

ftjets

I thought about it and can't imagine why i settled for 30% just because it's all they had. I'll return the 30 and order 15%. I've always flown with 15% heli fuel and had plenty of power for my flying. Can't imagine doing the 3d thing for awhile. Thanks for the help.