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Help with GMS 47 engine adjustment

Hope I provide all the info relevent if not let me know. I have a GMS .47 engine. Its got about 1 gal of 15% glow fuel run through it (the engine is not that old). There are no bubbles present in the fuel lines while engine is operating. Problem: the engine cuts out at anything higher than half throttle. This happens whether there is a glow starter attached or not. I've adjusted the low end throttle is that the engine responds well to low and mid range throttle changes. Once its at half or higher throttle setting the engine simply quites. It doesnt speed up and quit. It just dies. I've tried adjusting the high end throttle from about 1.5 turns open to nearly full open in 1/4 turn increments. The problem persists... So whats going on??? Greatly appreciate the help...

Reply to
Jet Red
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On 10/22/2003 7:05 PM Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:

It sounds like you are running out of fuel. I would check your fuel system from the tank to the engine (make sure there are no sharp bends, pieces of lint blocking the needle valve or clunk), and make sure your pressure line from the muffler to the tank is OK also. Several of the aftermarket mufflers do not provide adequate back pressure to the tank. I have a couple of Pitts mufflers I have had to block off one of the ports to get adequate pressure.

Reply to
Ted Campanelli

I don't have a filter inline with the clunk. I suppose its possible the needle might have some small debris caught in it. I'll check... By the way, I recently took my tank out and checked the clunck and fuel lines. All good. Haven't checked the internals to the needle however... Thanks

Reply to
Jet Red

I had a similar problem with a big super tigre. It turned out to be debris in the spray bar! Once I cleared it out she ran like a charm. Also examine your high end needle carefully to be sure a burr hasn't developed on the end of it.

Reply to
jeboba

Try backing out the idle screw (make it richer). Set up the high end before the idle. Then after each idle adjustment, reset the high end again.

Reply to
Harry Kolomyjec

I had similar problems with my GMS 47. Turned out I was making adjustments in to large of increments. I think I started it at about

2.5-3.5 from full in and started adjusting from there. I also leaned my low adjustment a bit. It was very frustrating, but once I got it right, it ran great. I actually prefer this engine over my OS 46 FX. Keep working with it.
Reply to
Dean

OK this is rediculous!!! I've tried everything... now I cant get the damn thing to run at all!!! it runs with glow starter attached only... that usually means it too rich on the low end! so I lean it out 1/8 of a turn at a time! then it won't start because its so damn lean its not getting any fuel... theres no in between! this is too hard.. it shouldn't be this hard there must be something else wrong!!! halp.. any ideas???

Reply to
Jet Red

Have you tried another glow plug?

Reply to
w4jle

Just for giggles, change your glow plug again. You did do that first, didn't you? Stuff happens, and the "it runs with glow starter attached only" line sounds familiar.

Reply to
John Alt

Have you treid to get experienced help? Ther is definately something wrong and the fact that it used to run at low RPMS means something you did caused the current problem.

Try replacing the glow plug and running a small fiber through the spray bar (after you remove the throttle barrel. Also, try pressurizing the tank with the barrel removed and the main needle open about three turns. You dhould get a good stream of fuel through the spraybar. If not, then you still have a blockage in the carb. You DID rinse out the tank before installing it, right?

Reply to
Paul McIntosh

What type of glow plug are you using? I had a little trouble with my GMS 47 until I put an OS #8 plug in it. Has been running great ever since.

John VB

Reply to
jjvb

Those of you that recommended checking the glow plug... Thanks you much!!! I changed out the plug last night and put in a long, medium heat plug with an idle bar and after some needle tweeks it runs great... Man what a relief! I thought I was loosing my mind there for a while. No obvious visual problem with the old plug but that just goes to show you. Thanks again to all for your help...

Reply to
Jet Red

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