G16 Doesn't Want to Quit Running

[JanisonHunter]

Hello!

I recently acquired a stock Yamaha G16. I do not have any history on it. The cart runs great, but does not want to stop running. When the accelerator pedal is released the cart continues to run for 5-15 seconds. I can usually turn off the switch, tap the gas pedal, and get it to stall out. I just performed a service on it- new fuel filter, spark plug, air filter, oil change, etc. This had no effect on the condition. I pulled the floor and checked the engine stop switch- it appears to be working. I can manually push the button without anything happening, then release it and the engine promptly starts. I also checked the accelerator cable adjustment and it seemed fine- not too tight. Any suggestions on where to look? I have narrowed it down to an electrical problem that keeps this thing sparking or a carb problem. But it is important to note that this thing runs great. A light choke on a cold start and it runs like a top. Any help would be appreciated. I just don't have a clue of where to start. There doesn't appear to be any broken wires or anything like that. And the cart will eventually stop running (10-15 seconds later), but I can usually stall it out in 4-5 seconds by playing with the gas. I haven't had to pull the spark plug boot or anything to make it stop.

Thanks!

[spriddle]

My first thought is pedal switch and possibly accelerator cable but you've checked those two items. Does the throttle on the carb completely close up after it runs for a minute and you let off the pedal? There are two cables: one to the carb is a small one running from the governor. Maybe an issue there where it's not releasing properly. Just a thought and best guess at this point. And it may end up being a faulty pedal switch: clean all the connections to the pedal switch and triple check that it is not sticking. Also, check and clean connections to the ignition module and so on...

Be sure if you run test the cart to jack it up and use jack stands. Be careful around the clutches. These carts can be dangerous and lunge forward very quickly.

[JanisonHunter]

Thank you for the reply!

Is there an easy way to test to see if the carb is sticking open or not closing all the way? This might make sense. Because I can shut off the switch and play with the gas pedal a little and make it stall. I would assume that an electrical problem would be present always.

As far as the pedal switch- I do think it is okay, but I can recheck it. I pulled the floor pan. Cleaned the area really well and put a little oil on it. The plunger seemed to be moving correctly and I could manipulate it with a screw driver to prevent the engine from starting, release the plunger and it immediately started up. I repressed the plunger (manually) while the accelerator was partially depressed and the cart continued to run. I know these have a magneto set up (don't they?) so if it is still getting gas and turning over- it'll keep sparking and continue to run.

[Mike Mac]

If it still runs after the key switch is turned off, the key switch is the start of your problem.

I'm wondering if the selenoid is stuck in the closed position.

After rereading, I think the pedal switch needs more testing.

[JanisonHunter]

How would you suggest starting to tackle this pedal switch?

[smallblock450sl]

If you beleive the "stop switch" is good, could be several other things. Yes, the throttle shaft must be closed. May need to take the airbox off, push the pedal and see if the accelerator cables are not allowing it it return to full closed position. Could be the "engine stop relay" (little cube with a blue top, next to the solenoid), unplug it and see if shuts down. A slight possibility is the "voltage regulator", unplug it and see if it cures the problem. Check the "blue/black" connector (at the front of the engine) into the wire harness for a good connection.

[nobuckbuild]

check the pedal switch circut , there are two plugs in that line one at the switch and another just below the shifter in the engine bay near the frame , sometimes people will jump out the circut there and you test the switch and never see that two feet back its jumped out

[JanisonHunter]

When testing the engine stop relay and the voltage regulator....both of these are behind the box close to battery, correct? If I unplug it and it cures the problem, then that is the problem? Just trying to see how diagnosing these regulators/ switches works.

[spriddle]

Keep us posted on your progress. Too bad you don't have a good friend near by with a G16. You could swap a couple things out to test. Still think its going to be a bad pedal switch or connection somewhere.... but not positive so let us know how it goes.

[cgtech]

Originally Posted by nobuckbuild

check the pedal switch circut , there are two plugs in that line one at the switch and another just below the shifter in the engine bay near the frame , sometimes people will jump out the circut there and you test the switch and never see that two feet back its jumped out

not quite correct, no jumper involved. the plug allows the stop relay to ground out the coil system when pedal is not pressed (& kill spark). if you just unplugged it (blue & black 2 wire plug at front base of engine) the coil would always be able to work. because the stop relay cant ground out the coil if its unplugged. this is where i would start diagnosing tho. the main solenoid only applies power to the starter/generator, it has nothing to do with the ignition system (which must still be active if the engine is runnning). the pedal switch is not gonna keep the engine running if the key is off & the keyswitch wont keep the engine running if the pedal switch is off, both of those would have to be stuck in the on position at the same time to cause this problem, not a likely scenario.