I use a GMS .47 in my Mid-Star
I just bought a GMS .76 for my Dirty Birdy. The .47 has been running real strong with a great idle. Hope to have the same results with my .76

I love my GMS 47, it starts easily, transitions to full throttle smooth and fast, spins the same prop 1000 RPM more than my OS 46FX and best of all it only cost $59.00 with an old engine trade in.
Todd.

I have the .76 on a Kangke Extra. Very happy with the engine. Easy starting anf good running. Using an APC 13x6 with 15%. I'm currently experimenting with different prop combos for this plane.

I have a GMS 47. It runs good but it wont shut off.I am getting 15000 rpm with a tuned pipe and a 10x6 APC.Same setup with a 46FX I get 15400 rpm.I'll stick with my OS

10x6 on a 47??
I'm surprised you have not blown the Rod.
I'm running an 11x7.5 Scimitar on mine and I can almost hover it. Put the Factory muffler back on and I bet you'll get better results
PS
That 400 extra RPM's costed you like 100.00

love my .47...it'll pull my ultrastick 40 outta sight with an 11x4. can't beat it for the price!

I've got the 47 on my Ultra Stick 40 & it pulls it like a Bear! I'm using an 11/6 prop & it will hold it in a hover as long as I can hold it and has unlimited vertical.
The only thing I dont like is w/ the throttle completly closed it still wont quit. I have to pinch the fuel line to shut her down. Oh well, I cant complane, I only paid $49 for it brand new!

I along with 2 other RC flyers paid $75 for the new Raptor II engine introduced on RC Online about 3 yrs ago. The Raptor II ran into production problems so the dealer (Sky Hobbies) offered our money back or a GMS 47. We all took GMS 47's. I never used mine but the other 2 installed them on Hanger 9 Adnance ARF's. One of the engines connecting rod broke at the bearing where it connects to the crank. Later found out the rod was welded at the point where it broke. The other guy tolerated his GMS for a few months and re-installed his 46FX. Mine is sitting right here in the box. The head is still gold, the shims and muffler are still unused. I fly 2 Dazzlers: one with 46FX and the other with a 46SF. The now defunct GMS 46 (now the Tower 46) is an exact duplicate of the OS 46SF.

FUNFLYER- What prop are you using to get a 1000 rpm more than an 46fx? and what rpms are you getting

I've had 3 GMS 47's they wear out fast
I have went thru 7 muffers, they break at the transition where the header & muffler join, not enought metal to put up with the vibration caused by poorly balanced cranks. And yes all my props & spinners are balanced. They don't shut off, the carbs jam up or fall apart.

AND the manual suggests the use of a 9x6, which I was never brave enough to try, so a 10x6 is not a problem.

ramcharger,
If you wanted to get rid of it, I'd gladly take it off your hands.
With a MCP.
12x4 APC 14K Tuned Pipe
11x4 MA 16.2K Tuned Pipe
11x5 MA 15.2K Tuned Pipe
11x7 MA 13.26K Tuned Pipe


Spicoli,
If you tune the pipe on the GMS, it'll smoke the .46FX with a std muffler.

I put a GMS76 in a GP Extra 300S .60 and it ran perfect. An APC 13x6 seemed to be the best prop for it.

No longer support RCU

What kind of RPM are you guys getting with the 13x6? nitro%? APC or MA?