We'd consider a 15x8 prop as much too large, and 7,400 RPM at full throttle as much too slow. We'd be surprised that you're not overheating the engine at that RPM.

We tend to prop the engine so that it will turn 11,000-12,000 at full throttle when leaned to peak on the ground. The engine will be running in its best power band, and will give you the best throttle response when propped to run in that range.

We tend to run APC 12x8 or 13x6 or 7.

We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)

DID YOU KNOW that our web pages now all contain FAQs? (Frequently asked questions) Please drop by and take a look! We hope you'll find the information helpful and valuable to you.

Sincerely,

Bill Baxter, Manager
Hobby Services
1610 Interstate Dr.
Champaign, IL 61822
USA

Phone: 217 398-0007
Fax: 217 398-7721
Email: [email protected]
Web: http://www.bestrc.com