Engine runs when key is switched off 310-8

[dschepis@hotmail.com 0]

My 310-8 doesn't stop running when the key is switched off.

 

I throttle her all the way down and turn off the switch.  She'll backfire out the muffler but keep running until I lift the hood and jerk the plug wire ( 10 HP Kohler).  Looks like the seat switch has been bypassed as has the clutch switch.

 

Tractor is new to me but has seen better days.  Just got the old girl running after cleaning out the fuel tank, new lines, inline filter, etc.

 

Should I just put a battery disconnector on to stop the engine? Are replacement ignition switches available?  How does the kill wire work?

 

Thanks

Don Schepis

 

 

[953 nut 59,215]

 

You should have a Magnum Kohler on the 310, if so the magnito will be grounded out by the ignition switch when in the off position, make sure the wire hasn't broken off, if so that would be the problem.

 

If that isn't the problem others may have an idea.

 

 

Edited April 7, 2014 by 953 nut

[wheeledhorseman 579]

I've found the ignition switches can indeed become faulty in repect to failing to shut down an engine with magneto ignition. So if you've checked the wiring and that the switch body itself has a good earth and it's still not switching the engine off, it can be the switch itself. 

 

From the way you describe it backfiring it certainly sounds like an intermittent conection in the kill wire circuit which can be caused inside the switch as well as the wiring to it.

 

Hope this helps you.

 

Andy

[KATO 115]

Welcome to   And yes you should be able to get a new switch if it turns out that

is whats wrong... here a link to Toros parts viewer, just select your year/model number

 

http://www.toro.com/en-ca/parts/Pages/PartsLookupResults.aspx?searchTerm=310-8&BasicSearchFilter=equipment

 

And heres a link to a price assuming its the right year i used ???(1988)

 

http://www.jackssmallengines.com/searchresults.cfm?cx=008737122150761418589:c24nnqwh7co&cof=FORID:11&q=111215

[gwest_ca-(File Mod) 11,388]

Looks like Jacks has a mistake there. Switch is too many $.

Suspect the part number should be 430128 or Stens # 430-128.

 

Garry

[dschepis@hotmail.com 0]

Gentlemen,

 

Thank you all for your input and information.  I do appreciate the help.  Your explanations make sense and I think I understand the problem.  At least now I have a direction to go.  Some of the various terminals are all corroded up and I suspect some of the earths ( THX Andy ) need to be re-established.

 

If I can get her through plowing up a vegetable garden, then I can garage her all summer for a complete tear down.

 

Thank You All Again,

Don Schepis

[Save Old Iron 1,568]

To stop the engine,

 

the M terminal of the ignition switch grounds out the WHITE wire in the harness leading to the magneto. When the white wire is grounded, the magneto cannot produce spark and the engine either stops or cannot be started.

 

 

Another wire may lead from the seat switch to ground the magneto if the operators leaves the seat while the PTO is engaged.

[dschepis@hotmail.com 0]

Saving Old Iron,

 

Thank you,  According to the Toro partsfinder that KATO linked me to, My model and serial number is for a 1991 machine.  It does have the Kohler magnum 10 engine. 

 

Based on the schematic you posted, I get no continuity to ground between the white wire terminal and ground terminal on back of the switch when the key is in the off position ( only difference is my switch has 5 terminals instead of the 6 illustrated).

 

This supports the suggestions that the magneto isn't grounding out to kill the engine.

 

Now I understand memories of touching the metal tab to the plug on old engines to turn them off.

 

Well, I learned something.  Thank You all.

 

Now to chase down a switch

[Save Old Iron 1,568]

The 6th missing terminal may be the ground terminal. On a dash panel which is plastic or ungrounded. a jumper wire from the G terminal to chassis will assure the ignition switch can ground the magneto when needed.

 

You may want to check for continuity between the switch body and chassis ground. If for some reason the body of your ignition switch is no longer grounded, this would cause your symptom regarding the ignition not being killed.

 

.

[wheeledhorseman 579]

As chance would have it I was working on the lower dash panel of my 316 yesterday. Although a 316 doesn't need an earth for the ignition switch these panels seem to have been made in a 'universal' way by masking off the area round the hole for the switch with a bit of tape before the panel was painted.

 

Obviously this helps the serrated washer that sits between the switch and the panel make a good earth connection (when a kill circuit for magneto is needed) but the area had become rusty over the years and I couldn't help thinking that the earthing would also rely on the screws that hold the panel in place as well. Not an especially clever design.

 

Andy

[dschepis@hotmail.com 0]

Andy,

 

I agree on the clever comment. My dash panel is rusted and the area under the bolt heads is painted and is now rusted.  Per save old iron's comment I could run a ground lead off the terminal to the chassis ground and probably will with a new switch.  But based on what I learned here, my switch is crapped out and no longer makes connection for the magneto lead to ground in the off position.

 

I've been working on a sleeve hitch for my moldboard plow this week and finished welding it up this afternoon.  I think I can run a temporary kill switch so that I can get the garden plowed this weekend.  Then I'll start on a more permanent repair.  I was able to temporarily rig the plow yesterday and turned over a few rows.  I'm really starting to be impressed with the pulling power this little old tractor has.

 

Thanks,

Don Schepis

[Save Old Iron 1,568]

Don, just to be clear,

 

do not run a ground wire directly to the M terminal on the switch. If your switch has a G terminal then yes, run a wire from the G terminal to a good chassis ground. If the G terminal is absent, make sure the metal panel supporting the ignition switch is grounded and the "neck" and fastening nut of the ignition switch is in contact with the grounded metal panel.

 

If you run a wire from the M terminal to the chassis, the magneto will always be grounded and the engine will not fire.

[dschepis@hotmail.com 0]

Save Old Iron,

 

Thank you.  I understand. 

 

I picked up a little 20 amp toggle switch today that I was going to patch in between M terminal and ground.  I am only using it as a temporary kill switch.

 

Hopefully I'll get my plowing done this weekend and then I won't need the tractor for a while.

 

I bought it specifically to turn over the sod for a big garden patch and then it will have a snow blade on it for winter driveway use and other hauling chores. 

 

Thanks,

Don Schepis

[bowtieguy 334]

Don...send me a pm if you need a harrow or a snow blade for your horse...your 310 is a HORSE for sure

[dschepis@hotmail.com 0]

Not sure how to PM,

 

I have a snow blade and an 8 point cultivator, but I'd be interested in a correctly sized disc harrow.

 

Thanks,

Don Schepis

[2bcross3 1]

Thank you for the topic replies. Mine started doing the same thing today. Still ran after turning the ignition switch to off. I did find out if I pressed in hard on the key it would shut off. Pulled the ignition switch and found the "A" terminal all corroded. I'll be cleaning that up and checking for good continuity on the "M" wire and good ground.

Tapatalking from my galaxy