OK, I'm stumped. I've got a Craftsman 46" lawn tractor (model 917.272121) with an 18.5HP Kohler (CV18S). A couple of weeks ago I go out and start... make that try to start it and nothing. I jump it and get it running, warm it up, depress the clutch/brake, put it in gear, and as soon as I let the clutch/brake up, it dies. The battery still has enough juice to start, so I begin fishing for problems.

I check the kill switch under the seat, nothing. I then find the switch interlock push-in (153664) and figure out how it works. A little duct tape later and I've now got it running. Mind you, this is just so that I can isolate the problem. I drive it around and conclude that I'll be buying a new switch interlock push-in. Then it happens.

I reach for the attachment clutch switch to engage the blades and it dies on the spot. Argh!

The next day I put a new battery in it, and I've got a new switch interlock push-in on the way, but if it's not the switch interlock push-in then I'm going back to the drawing board.

Anyone have any ideas? My choices are buy a bunch of parts and try them one at a time, or buy one, wait a week, test, fail, buy another, wait a week, test... well you get the picture.

Thanks,

Slick

 

Go through a troubleshooting online query with sears craftsman site. Or google it. It should narrow it down. I was having a similar problem with mine, and it was a choke issue.

 

one other thing you might try it to disconnect the batery.turn key to off position and remove key.then after this is done lift the front on the mower(a jack will do this nicely)and see if you can turn the blade by hand.the bearings may have siezed up and put too much drag on the motor.

 

If it's shutting off as if the ignition is being killed, then I'd suspect the plunger connecter on the seat switch. You can isolate this by clipping one of the wires going to the seat switch connector. (I assume you'll be doing this anyway, to replace it). If it works properly, then that's the problem, provided the switch itself is working correctly. If not, post back with results and we'll go from there.

 

Thanks for the responses so far! Here's a little more information that might help narrow down the problem.

BTW - www.craftsman.com has been down for maintenance for the last 8-10 days. I'd love to find an on-line trouble shooter if anyone knows of one.

OK, I checked the seat switch and ruled that out. Then I started trying to isolate the variables. I unplugged and re-plugged a variety of connectors to see what I could make happen. Nothing seemed to make a difference, so I pulled the mower deck off and guess what... it still doesn't work.

Once I have the engine running and engage the blade switch (attachment clutch switch) the engine dies immediately. I'm thinking it's an electrical issue, or the electric clutch is locked up. I'll be pulling the clutch off tomorrow so I'll know more then.

Thanks,

Slick

 

Sounds like a safety switch problem. Could be in the pto switch itself.

 

Operator Presence Relay!!!!

The mystery has be solved. I cracked it open and it was rusty. Cleaned it up and whammo! I'm back in business. It was pretty much shot so I ordered a replacement and that solved my problem.

Thanks,

Slick

 

Wow, I bet it really need smowing by now! Thanks for the update, and glad you got it fixed!

 

Could you be more specific on what fixed the problem? I am having similair issues - not all the time, seems to be after the engine has been running 10-15 minutes, so it could be a switch.

Thanks

 

The relays get rust inside and the contact points don't make connection. Cleaning the relay or replacing it would be the fix in this case.

I don't think your problem is the same though, since you siad it will run 10-15 min before stopping. Will it start back up, or does it have to cool off first? Does it have spark just after it dies?

 

I have a similar problem, already bipassed the switch under the seat.If thats what you mean.
Runs well until I depress the clutch or engage the blades. even in neutral, then it dies.

 

Where is the OPR , dont see that in the schematic?

 

Wow, I really wish I would've found this thread much earlier. I had a bogging, stalling, backfire and finally dieing out problem. I bought it used so once I began having problems with it (in the middle of this (the first) season i had it) I gave it a tune up (oil change, air filters & fuel filter). No joy. I then tested the safety switches, duct taping them down because I have no continuity tester (the switch when engaging the mower blades and the seat switch). I was still getting sputtering... ugh. I then replaced the the 20a fuse, fuel tank, the fuel lines and hoses along with another fuel filter, I also remembered that I forgot to change the plug. All this between having to buy a new plunger assembly to raise an lower the deck, a new deck belt and blades, I was about ready to give up. Finally I cam across this thread. After removing the Operator presence relay the machine ran like a top. I immediately ordered PART NUMBER: 109748X. Thank you! I owe Slick a beer.

I have a LT 1000 lawn tractor model 917.272061