G1 will not idle

[b_colwell]

I have done and replaced everything I can think of and this Yamaha 1986 G1 will not idle slow. Runs great when driving, let off the gas and it will idle for a few seconds then die(unless i have the throttle stop screw screwed way in).

I have replaced the oil seals, on the air test it will hold 5 Lbs for a couple of days. I have replaced the carburetor, I have replaced the reed assembly. It pumps oil.
I have tried adjusting the Pilot screw. I set it to factory spec. one turn out. I have tried it at 1 turn, 1.5 turns, 2 turns, three turns, .5 turn, seem to be no difference.
I have set the exhaust butterfly so that it is just open when the throttle is closed. The muffler should be OK since it runs great at full throttle.

The only thing I have not replaced is the air chamber, have not been able to find out what it does.

I would appreciate any suggestions on where i go from here.

Boyde

[mikeasis]

Golf carts do not idle. there is no idle circuit in the carb. they are meant to shut off when you let off the throttle and restart when you press the throttle. I know its weird and takes some getting used to. the air chamber is just that....an air chamber. In some literature ive seen it called a boost bottle but i thnk most g1's did not even have them

[b_colwell]

Yes I realize that the G1 is meant to shut off when the gas pedal is released, however if I disconnect the black and white wire as described in the shop manual it should idle. It is the shop procedure to set the idle rpm to 1000 with no belt or 1200 rpm with the belt engaged.
I believe from the service manual that it is meant to idle if the shut off switch is disabled.

Thanks
Boyde

[b_colwell]

Thank you for the lead into the Air Chamber, used the term Booster Bottle, as suggested, did some research and I understand its function better. I am going to try removing it from the carburetor side and plugging the pipe to see if this has an effect on not being able to idle low.

Any help with my problem will be appreciated.

[b_colwell]

Well, I unplugged the Air chamber/Booster Bottle and plugged the pipe going into the intake(Carburetor Joint), there was no difference, still will not idle.

As an experiment I screwed the Pilot Adjusting screw all the way in, no difference, runs good at medium to high RPM, runs OK at idle for a few seconds then dies, no difference.

I checked the old carburetor, screwed the pilot adjusting screw all the way in, counting the turns, it was at 3 and a bit turns out.
I duplicated that on the new carburetor, no difference.

HELP!!!!!!!!!!!, I do not know where to go from here, please a suggestion.

Boyde

[mikeasis]

I'm guessing your by passing the switch at the pedal trying to get the cart to idle. Golf carts aren't meant to idle i don't think there is an "idle" circuit in the carb.

[smallblock450sl]

If you want a G1 to idle for testing.....unplug the black/white wire as noted. Then turn in the throttle stop screw, not the air mixture screw.

[b_colwell]

I think I discovered the issue. BTW, yes I could turn the throttle stop screw in until it idled, but too fast,the cart would run away on me, and it travels too fast down the field without any pressure on the gas pedal. Can only do that if it is up on blocks.

I examined the spark plug, lots of carbon, indication that it is running too rich, too much gas, not enough air. Air leaks typically cause it to run lean, too much air not enough gas. So no air leaks, screwing the pilot screw in or out causes no difference, so my not enough air problem is caused by something else. Also, I found my compression tester and tested that, 120 PSI.

So it idles fine without the air cleaner.

Brand new air filter is in it, with a new foam sleeve over the filter. I removed the foam sleeve. That was it. I was able to dial the rpm down so that it will idle without taking off.

Thanks for everybodies suggestions and advice.

[b_colwell]

Just some further information. The air filter did help, but I did find the real problem after more research.
Here is the story: My weed eater would not idle this year, it ran and idled fine last year. This got me thinking, when my chainsaw will not idle, I clean the "spark Arrester", a part of the exhaust. I removed the muffler from the weed eaterm cleaned the spark arrester and viola, the weed eater ran perfectly. The light bulb in my head came on. The golf cart has a muffler, it is 2 cycle, it is old. So I removed the muffler from the golf cart, built a fire in the backyard fire pit, put the muffler in the fire, kept a hot fire burning all afternoon. There was smoke and flames pouring out of it for hours. After 4 or 5 hours the smoke from the muffler stopped.
Remounted the muffler, it now idles and runs perfectly.
Thanks for your help.