ORIGINAL: CGRetired
You can find a range of props for that engine. It all depends on what performance you want. Smaller pitch props (the second number in the prop size) will usually cause more RPM. So, you will have to watch that so you do not exceed the max RPM for your engine. It is not unusual to get 12,000 RPM out of that engine when it is running correctly and correctly prop'ed.
Think of the pitch as changing gears in your car transmission. Lower gears relate to lower pitch numbers. You get more power, faster acceleration, higher RPM, but less speed. Higher pitched props will give you less power, slower acceleration, lower RPM, but higher speed. But, at limits. You cannot, for instance put a 15-10 prop on a 46 sized engine. It will run, but you will never get the thing off the ground.
CGRetired
Thanks for the explanation. It makes perfect sense to me now. Went flying this morning and was intending to try 11x7 and 11x8 but didn't get a chance. Spent most of the time just enjoying the plane with the 11x6 and letting my son and cousin fly my trainer with the buddy box. Next time, I am going to try switching props. Thanks again for the info.
DocWill,
The manual that came with the engine (brand new about a month ago) lists the different "suggested proprellers" on page 15. Then on page 16 under the heading of "Before Starting" it lists the 11x6 as a suggested size. The manual does not give a suggested size under "break-in" so I just presumed 11x6 was the correct one. The engine is broke in now. So I can experiment next time. The manual tells you not to make successive "nose-up" flights for three or four flights. I just followed the directions, because I thought that would be best for the engine.
By the way, after that motor was broken in and dialed in, with the 11x6 on a dry lake bed strip, the Pulse XT lifted off after about 50' and then I could swing around it would pull straight up almost out of sight (well, until my neck hurt anyway)! I am having a blast with this plane.