Does anyone have any tach readings for a ST 75 that is fully broken in? There are no postings for this engine in the tach forum.

Mine is not fully broken-in, but great and cheap engine.
When it takes ten more flights, i will post tach readings. I use APC 12x6 but when break-in finished i will put in an APC 12x7

Best regards

Great!

I'm breaking mine in on a 12 x 7 and keeping it below 10k for now. Only 3 tanks have been run through it.

We break the engine in at full throttle with a 12 x 8 propeller. We start out very, very rich and gradually work the mixture to peak RPM.

When the engine's had about an hour's run time on it, we'll have leaned it to peak RPM and see mid- to high- 12,000's.

Fly with an 11 x 9, 12 x 7, 12 x 8 props. 12 x 6 or 7 aren't too bad, either. It all depends upon what your plane needs to fly the way you want it to. If the engine turns in the mid- to high 12,000's, you'll be OK.

Thank you Bill. That's excellent info.

I was seeing 11k after third tank, but felt uncomfortable leaving it there throughout the whole tank (14oz).

I'll be putting it in a 7lb Dirty Birdy, 15% Omega with additional 3 oz castor, APC 12 X 7 (break-in and flight), and an Enya #4 plug. Seems to be a good combination with no detonation.