DISABLED VET NEEDS HELP AND NEEDS IT BAD BOLENS ST120/ 3212G

[ACHTUNG]

My Bolens ST120 (3212G) with a Briggs and Stratton 12 HP would not start this spring, and additionally had a batttery draw, so I had a new stator and resistor installed by my local small engine repair garage for $160. Now a new frustrating problem has arisen. it is somewhat intermittant, and therefore is driving me nuts.

When I got it home, started up beautifully, and backed her off the trailer. I switched on the PTO enagaging the blades, and VROOM, I was mowing. For about 30 feet. Then she began to stall. I put my foot on the brake/clutch, and it came back to life. Now when i start it, it stalls when i back my foot off the clutch pedal. I've tried every combo of in gear, out of gear, PTO on, PTO off, etc, etc.

Here's where it gets INTERESTING and confusing at the same time: I noticed this round rubber grommet on the deck that IS DEPRESSED WHEN YOU HOLD DOWN THE CLUTCH. (see pics) I figured maybe I could bypass the clutch JUST TO TROUBLESHOOT - NOT FOR PERMANANT. underneath, it has 3 wire leads coming from it. One large one in the middle, and two smaller ones on either side. I unhooked the middle one, and VOILA, it ran again WITH MY FOOT OFF THE CLUTCH - for 2 rows of 40 feet. Now, same problem - back off the clutch - in gear or not, PTO engaged or not, and it stalls dead - just like a dead man switch. Could it be the repair man crossed a wire or what? This is frustrating - i prefer the PTSD!! In short it starts and runs great, as long as I leave my foot ON that clutch pedal. If not - stall. I sure could use some advice. I'd like to have some info to bring in with me. I can't afford them blindly searching on a disability pension.

UPDATE: WEIRD TO WEIRDER, BUT IT MIGHT HELP: As i was sitting on this thing trying to figure this out, I noticed when i adjusted my ***** in the seat, it affected the aperformance. i noticed that the safety switch undert he seat would make the engine stall when DEPRESSED - WHICH IS OPPOSITE OF HOW IT'S SUPPOSED TO WORK. So I disconnected the leads, and it ran fine for a good long while. Not perfect - it sputtered and spat, but ran definately better. Could there be some sort of connection between th wires for the seat safety switch and the wores under the rubber grommet switch i described under the clutch pedal? MY GOD HELP!!

 

[scott47429]

sounds like either the clutch safety switch or the seat switch and if i was a betting man i would guess the seat switch if it has one

 

[Rivets]

Definitely the seat safety switch. Look under the seat and you will either see a small push button switch on the chassis or wires going to the underside if the seat. This switch is a normally open switch which must be pushed in by your body weight to allow the PTO to work properly.

 

[ACHTUNG]

Definitely the seat safety switch. Look under the seat and you will either see a small push button switch on the chassis or wires going to the underside if the seat. This switch is a normally open switch which must be pushed in by your body weight to allow the PTO to work properly.

(not sure how this works, but will send this as a private msg as well as replying in thread - I'm kinda new at this)

I ended up pulling BOTH leads of the safe switch under the seat, and you are right, it did seem to run better. As I said, it sputtered and spat, but it ran better. I am confused by the following though:

1. Before I pulled the leads to the seat safe switch, they were firmly in place, and have never been an issue before.
2. Although it ran better, it only ran a BIT better - not markedly so. At least it didn't stall.
3. AND MOST IMPORTANTLY: When I first got it home, it DID run for 30 feet or so before it stalled. When i put my foot BACK ON THE CLUTCH it revved righ back up. WHAT WOULD ME PUTTING MY FOOT BACK ON THE CLUTCH have to do with the seat switch.
4. MOST CONFUSINGLY: This issue happened whether OR NOT the PTO was engaged! THE PTO had no change, on or off, as to this problem!

As it is, I have the leads to the seat switch disconnected. There are 3 leads under there, and only two - the two outer ones - were in use. the middle lead wasn't in use and there doesn't seem to be any wire for it in the harnes anywhere.

Any other thoughts?

An Appreciative Jim, Remer MN

 

[Rivets]

The seat switch tells the engine someone is there. You can override the seat switch by locking the parking brake (clutch) in place. This is how techs can work on a unit without seating in the seat.

 

[Rivets]

For diagnosis purposes only try running a jump wire between the two outside wires on the plug and see if it runs smoother.

 

[ACHTUNG]

(not sure how this works, but will send this as a private msg as well as replying in thread - I'm kinda new at this)

I ended up pulling BOTH leads of the safe switch under the seat, and you are right, it did seem to run better. As I said, it sputtered and spat, but it ran better. I am confused by the following though:

1. Before I pulled the leads to the seat safe switch, they were firmly in place, and have never been an issue before.
2. Although it ran better, it only ran a BIT better - not markedly so. At least it didn't stall.
3. AND MOST IMPORTANTLY: When I first got it home, it DID run for 30 feet or so before it stalled. When i put my foot BACK ON THE CLUTCH it revved righ back up. WHAT WOULD ME PUTTING MY FOOT BACK ON THE CLUTCH have to do with the seat switch.
4. MOST CONFUSINGLY: This issue happened whether OR NOT the PTO was engaged! THE PTO had no change, on or off, as to this problem!

As it is, I have the leads to the seat switch disconnected. There are 3 leads under there, and only two - the two outer ones - were in use. the middle lead wasn't in use and there doesn't seem to be any wire for it in the harnes anywhere.

Any other thoughts?

An Appreciative Jim, Remer MN

Ok, that helps a bit. Now i see how they're related. As I said, there were 3 leads coming off the bottom of the seat switch, a center one that wasn't being used, and two outer ones with were. When I noticed my Butt was affecting the whole thing, I just disconnected (pulled off) the two leads. I thought I'd have to "Jump" them, but surprisingly I didn't. Next question is this: there isn't much to go terribly wrong with a seat safety switch, and it was never a problem before, so my next question - and you are being a saint here with your patience - should I re-attach the seat safety leads and look for a wiring problem elsewhere? And if so, where? OR...as long as she's running, should I leave well enough alone?

 

[ACHTUNG]

For diagnosis purposes only try running a jump wire between the two outside wires on the plug and see if it runs smoother.

Between what plug? the one under the clutch pedal or the safety switch under the seat?

 

[ACHTUNG]

For diagnosis purposes only try running a jump wire between the two outside wires on the plug and see if it runs smoother.

just to elaborate a bit more - I was confused because under the clutch pedal there are three leads and 3 wires in use. As I previosly stated unplugging the center one helped for about two minutes, so I reattached it. NOW...under the seat, there are 3 leads, but only two wires, and when i unplugged them, with the idea of just jumping them, turns out it ran better without even jumping them.

i am wondering if, in the spirit of doing it right, I should reattatch the two seat safety wires and search for a wiring issue elsewhere?

This is so confusing because before this spring's stator/resistor fix, this was never a problem!!!

 

[Rivets]

Ok let's start over, because I am just as confused. First I am going to explain how everything should work. To start an engine you must be sitting on the seat (seat safety switch) and either have unit in park or foot on the brake/clutch petal (clutch safety switch). As I said before, you can override the seat with the parking brake engaged. After the engine starts you must be on the seat to engage the PTO. if the engine cuts out when the PTO is engaged, the unit thinks no one is in the seat.
Second, I don't know what resistor they fixed. Are you sure that they did not replace the stator and the diode? If they did replace a resistor, can you explain where it was?
If everything worked fine before the repair, we should really start there with everything hooked up the way you found it, and then start from there.