fgj

Hi there . having problems with the GMS 47 . It starts great and idol is super. However at full throtle when engine is on the flat or pointing up it slobers and quits. We are on the 6th tank if testing and have tried ---- changing settings on high and low needles--fuel tank heights-- plugs--fuel--carb from another GMS 47--carb off and cleaned, reset needles--still when sittting on idol it is running good, then advance to high RPM and near full throw the enging starts to slober and dies out. Have put a perry pump on to see if lack of fuel would be the problelm, nop, same result. Any suggestions to get the engine going????? thanks Grant
please reply... [email protected]

Dmacsimum

I have the old 47 version when they first hit the market. It has been a real good engine, strong, idles well, and for the price was a great buy! I have heard though the quality and control has been an issue. Some have had bad ones, and others have had good ones. the bad ones don't run right at all, and the owners have cursed them however, the owners who have received the good running engines like me praise them.....
Buy one,
Dennis

Flypaper 2

A friend of mine had a new one that wouldn't quit at idle. I did a pressure test on it and it blew air out of the front of the crankcase as fast as I could blow it in. Sloppy fit between the crank and crankcase. Sent it back.

1Jimbo

My Feedback: (2)

I've been flying r/c for 20 years and never had as many problems with an engine as I have with the two GMS.25's(the new ones). The quality and workmanship is VERY poor, at least on the .25's. The casting is VERY poor. They leak air between the case and the front bearing. The throttle sticks because of the poor machine work to the stop scew slot. It does NOT have good fuel draw in tight turns even if you run it rich, and they do not stop when the throttle is fully closed. Even with my thumb over the carb. I sealed (RTV)every spot on this engine you could think of.All I can tell you is the GMS.25 is JUNK[:@] I thank god Tower took them back.

1Jimbo

My Feedback: (2)

By the way I replaced the two GMS.25's with Irvines. MAN what a world of difference, you get what you pay for with Irvines[8D]

bluesago

I guess I got one of the dogs. I did everything, sealed leaks, ran more fuel through it. It got better, but my patience ran out.

I bought an Irvine. It leaks through the front bearing too. []

Balin

HondaCRX

hey, has anyone ever tryed some rc car tricks on a .47? like porting, knife-edging the con rod, boring out the oil holes in the con rod, etc.

A. Souphound

Having read all of the posts relative to the GMS 47 it appears many of the complaints were fuel related. I recently purchased a GMS 47 with a remote needle valve. I always seal a new engine's backplate, carb and etc with high temp sealer regardless of the engine manufacturer. After running several tanks and flying on the 'rich side' I found the needle valve setting to be VERY sensitive. I removed the remote and placed the needle valve up front in the carb.....no more problems. I have the engine mounted on a GP Dazzler, and the engine has performed super using a 11/6 prop it turns nearly 15K. The muffler on the 'remote model' appears to be 'tuned'. I have read an article where the muffler placed on an OS. FX will turn 1300 more RPM than the stock O.S. muffler. Some of the fuel related problems could also be due to back-pressure. Tower dropped the price on the GMS engines, and I've sent in my order today.

All the best,
Alvin

tree

I have found that the idle needle is tapered to much causing the problem.I had a 40 GMS and it did the same thing yours is doing.I removed the idle needle from my towers 46 and installed it in my 40 GMS ran great.Using a micometer the taper on the GMS was .014 smaller than the towers engine needle

weskel

Could someone post the deminsions of the 1.20 size GMS, I want to buy one, but I need to know the size of it, to include bolt patterns for the mounting and for the muffler.


weskel

Spicoli

Here is a tip for people having problems with the GMS 47.There is a small channel between the front bearing and the carb.Air leaks through the front bearing and the channel.Fill the channel with RTV and air leaks stop and the motor will shut down with the throttle.
It worked for me.