917-271080 16hp Craftsman Riding Mower stalls immediately on clutch release.

I have a 16hp Craftsman that starts fine. It also seems to idle fine, maybe just a tad rich. I have rebuilt the carb with new gaskets, needle valve, and cleaned it out. I have checked the plug as well.

Everything seems fine until I let out the clutch and then it immediately dies. This happens even if the unit is in neutral. I can't seem to find the schematic for the wiring. Is there a bypass on the ignition switch or somehow it must know after it's running that it's ok to have the clutch out, right?

Any help is appreciated!

 

Plug the seat switch connector on tighter.

 

I also have pulled the connector off the seat switch which disables any grounding of the magneto circuit except the G to M on the start switch when the unit is turned off by ignition switch. It still dies immediately on releasing the clutch or trying to activate the PTO to drive the snowblower.

 

I am not sure I understand your reply. This unit has a normally open to run and when you get off, it grounds the magneto. So plugging in the switch better would only make it more sure of shutting off if the operator gets off because it would be sure of grounding the magneto.

 

Unplugging it doesn't disable it. There is a switch built into the connector which automatically grounds the magneto as soon as it gets unplugged... which is why I suggested plugging it on tighter. The connector lock tab tends to "relax" over time and let the connector back off just enough to allow the internal switch to think it is disconnected.

 

Sorry,
Not on this unit there is not.
There are two wires. They go directly to the seat switch and there is definitely NOT a hidden switch on the connector on this unit.
Interesting that you should insist that since I am sure I have the model number correct, having just checked it. But nevertheless the diargram clearly marked with this model number doesn't exactly fit the actual unit I'm working on. Maybe it's a early model or something.
Further checking shows that it does not want to idle either. The choke position on the throttle is with it up and as you push it out of choke it's in pretty much full open throttle. I had not really tried to run it at very slow RPM till today. I pulled the filter and there is plenty of gravity feed gas from the filter to run even a car! The gas appears clean and free of water and the fiber filter is not swelled as it would be if there was water. I'm guessing the volume would be 1/4 gallon a minute or better. The gas shut off on the bottom of the bowl seems to work. It definitely shuts off the unit if disconnected and 12V on it makes it pull the selonoid in it inside.
Maybe it's time to do a compression check? Timing is all electronic right? It has no mechanism to advance that I see. Perhaps pull the carb again and once more make sure all is ok but I don't see how anything is messed up there. The float is intact. There's a new needle. There is no adjustment on the float. Throttle valves are all intact and no leaking around the shafts.
Thanks for helping.

 

Oh, I also checked all belts and idlers and pulleys. Everything spins easily. I can turn the transmission drive pulley easily.
Correct me if I'm wrong, but this unit everything stays UNGROUNDED on the M terminal of the switch unless a safety is activated.

 

Ok, well. Two more things. One, the schematic for this unit is way off.
So far off I would warn anyone not to use it without double checking.
I took the wiring harness apart and clipped the wire ties so I could trace the wires.
As it turns out, it was indeed the switch on the seat. It's wired so that you can be off the seat and it will run but not if the brake is not set. If your on the seat, the clutch can be out and brake off and it will run. And you must be on the seat for the power accessory to allow it to run if activated.

Now another problem shows its head. Surging

I will open a new thread for this.
Thanks for taking time to read and answer.

 

Is the seat switch connector grey? I still believe you have what I am thinking. You can't see the switch.

 

How are you supposed to work on these tractors if you can keep them running while your off it?

 

Slugworth, normally there is an override switch on the brake that opens the safety circuit via the seat to allow getting off as long as brake is on.

 

lol..

Learn something new eveyday!!!

Put the parking break on and you can get off it

Thank's...