I was reading the manual but the suggestions are very broad, they range from 13x5 to 18x5 so I wanted to know if anyone knows what type of prop this engine likes. It will go on a .60 size Extra. What about 3 blade props?

G'day Mate,
Try a 15x6 or 15x7 APC, & see how it flys, experiment is the way to go.

My old Cermark Sukhoi (circa mid-'90s) flies great with a 13X8, 14X6 or 15X6. The 13X8 is a little fast for me, the 15X6 has a bit too much braking for my taste, so the 14X6 is a great compromise.

If you're going to spend your time hovering, you might want the 15X4. Good luck,
Dave Olson

If definately dependson the type of flying you will be doing. General sport flying and a 13x6 or 13x8 will work but for 3D stuff I would look at the 14x4W APC or 15x4W APC.

It's weird how everyone tends to recommend something in the 14x_ or 15x_ area but the manual will mention up to 17x_ and 18x_ diameters. I guess I'll go with popular knowledge.

G'day Mate,
This is taken directly from the 91FXring manual,
Sport
15x8,16x6~8,17x6
14x7 (3-blade)
Aerobatic, 13x11~13,14x10~11

It does not mention 18" props

You're right I thought I'd seen 18" but still there is a 17"... Anyway I think I'll experiment in the 14-15 vicinities.

A lot of times the size and type prop will depend on the plane, not just the engine. As stated you need to try different props in the expected range and see which works for you. I had a Cessna with an OS 91 and started out with a 13 X 6, but when I put floats on it I had to go to a 3 bladed to get clearance ( your answer about 3 bladed ). I ended up with a 12 X 6, 3 bladed and like it so well that I left it on after I took the floats off.

On mine the 3 bladed gave more breaking then a 2 bladed but it ended up being just what I liked. Like said, you need to try a few different ones to see what feels good to you. Just be carefull and don't over rev the engine. Just me, but I like to run an engine a couple hundred RPM under the recommended RPM.
ENJOY !!! RED

i have used 15x8 for years, i also use a 14x9 3blade on my extra each pull it around flawlessely for aerobatics