GMS .47 running too rich
05-12-2003, 12:46 PM
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GMS .47 running too rich
I have had this engine for awhile and burned probably 3 gallons of fuel.It has always ran great,until Saturday.Top end was great,but it was loading up bad on the low end.I had the low end screw turned at almost a full lean setting and it was pouring smoke out of the exhaust.It would hesitate for a few seconds when going from idle to full throttle.It just bogged down from low to high.It never deadsticked,but hesitated at the wrong times!Like when going into a low hover or pulling out of a low harrier.It idles great also,but I guess I need a little help of the lowend problem.PLEASE NO FLAMING 
I don't want people telling me to buy an OS,TT or another engine. I have three GMS engines and have nothing but good luck with them. Thanks in advance!
I don't want people telling me to buy an OS,TT or another engine. I have three GMS engines and have nothing but good luck with them. Thanks in advance!
05-12-2003, 01:08 PM
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GMS Carb
Went thru this last week , a friend showed up w/a GMS 47 that was running about like yours with a low/ lean setting on the bottom end. You are running off the top end. I shut the low end down(carefully not to damage the needle) and opened it up to about one and a half turns and then set the top end at two turns appx. Started up and adjusted trom there, it was fairly close. Set the high end first and then idel about 15 secs. accelarate and you will know if if you need to lean or richen the low end. Repeat as necessary. That little GMS impressed me what a bargin at 49.95 with a junker trade in!!!
05-12-2003, 03:33 PM
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GMS .47 running too rich
First, take the carburetor apart and clean it thoroughly. Make sure all the parts are present and accounted for.
Now, close both needle valves and open the main valve 2 complete turns. Put one end of a CLEAN piece of fuel tubing on the needle valve inlet, and the other end in your mouth. Set the carburetor to an idle. Blow into the tubing and slowly open the low end needle valve until you can distinctly hear air escaping. That will give you a starting point that is scarily close to right.
Now, close both needle valves and open the main valve 2 complete turns. Put one end of a CLEAN piece of fuel tubing on the needle valve inlet, and the other end in your mouth. Set the carburetor to an idle. Blow into the tubing and slowly open the low end needle valve until you can distinctly hear air escaping. That will give you a starting point that is scarily close to right.
05-12-2003, 03:38 PM
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GMS .47 running too rich
Rule #1, replace the glow plug (please spend the extra $$ and get an OS 3 or OS 8)
Rule #2 Try a fresh NEW gallon of fuel.
Rule #3 Clean and inspect carb, inspect and/or replace fuel lines. Check for loose bolts or anything that can introduce an airleak or fuel leak.
Rule 1,2 can account for most engien problems. An occasional bit of gunk in carb is another reason. Good luck.
Rule #2 Try a fresh NEW gallon of fuel.
Rule #3 Clean and inspect carb, inspect and/or replace fuel lines. Check for loose bolts or anything that can introduce an airleak or fuel leak.
Rule 1,2 can account for most engien problems. An occasional bit of gunk in carb is another reason. Good luck.
05-12-2003, 09:34 PM
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GMS .47 running too rich
Thanks for the info guys.I kinda figured I should clean the carb,I have replaced the fuel lines from the clunk all the way to the carb.Replaced the plug(tried two new ones) One thing I forgot to mention,I have a muffler from a OS .46FX on it ,instead of the GMS tuned pipe.Think that could have any bearing on the problem?
05-20-2003, 07:38 PM
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GMS .47 running too rich
Ok,I have had about enough of this engine now.It runs rich no matter what I do.It does not make since that is a air leak,then it would run lean.I have tried every kinda plug known to man.I have cleaned the carb,sealed the engine with RTV and even put a carb from my other GMS that runs fine.Now what would be the next alternative?
05-20-2003, 10:22 PM
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GMS .47 running too rich
Buy a TT!
Kidding!, just kidding!
Try taking the carb apart, maybe there is a gap between the housing and the spraybar? Somehow the fuel must be getting around the needle.
Kidding!, just kidding!
Try taking the carb apart, maybe there is a gap between the housing and the spraybar? Somehow the fuel must be getting around the needle.
05-21-2003, 02:19 PM
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GMS .47 running too rich
Yep, why didn't you tell us you were using a non-standard muffler in the first place? It is possibly that you have TOO much backpressure from your OS muffler and this is causing your low end to be too rich. Try removing the baffle if it is still in there. Also, try swapping mufflers from your other GMS engine.
Also, did you check to see if you have a headgasket? An engine with a poorly sealed head will suffer more visibly at idle than at full throttle but would probably cause more of a lean condition than a rich low end.
Also, did you check to see if you have a headgasket? An engine with a poorly sealed head will suffer more visibly at idle than at full throttle but would probably cause more of a lean condition than a rich low end.
05-21-2003, 07:09 PM
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GMS .47 running too rich
I used a bearing from my local bearing supply. The new one sealed a bit better, and made it possible to actually shut down. Easy to do too.
05-21-2003, 08:08 PM
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GMS .47 running too rich
I did the Boca bearing swap and also silicone everywhere and my .47 would shut down!
There were also alot of times when it shut down during transition from low to high. Many dead sticks.
I sold it because of this. Never could get it to be reliable. It made SUPER power but,,,,,, I could not get it set. I may buy another one one day and see what happens.
ZB
There were also alot of times when it shut down during transition from low to high. Many dead sticks.
I sold it because of this. Never could get it to be reliable. It made SUPER power but,,,,,, I could not get it set. I may buy another one one day and see what happens.
ZB
05-22-2003, 04:55 AM
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47
My GMS 47 has the low speed needle almost all the way in to get it lean enough on the bottom end. Others have them out over one full turn out to get the same. Looks like Chinese quality control strikes again. 
Todd
Todd
