Craftsman Tractor Ignition

[lefty]

Craftsman: 917.272761
Serial: 082003C016353

I got this with an intermittent issue that I've narrowed down to the ignition switch. I've removed the switch and can hold each side of the connection in my hands and when I wiggle it, I can hear the after fire solenoid clicking away as something makes and loses contact. It's a 4 position switch: off, lights, run and start. There are 7 prongs on the switch: B,L,S,M,G,A1 and A2. I've done some research and educated myself a bit on what all those mean except for A1 and A2. I'm assuming one of those is the afterfire solenoid.

I want to test the switch because as much as I fiddle with it, I can't isolate the problem. I know it exists in the switch, the connector on the harness, or the actual contact between them. Part of me just wants to get a new switch and see if that's it. It's not much money for the switch. Would that be the proper protocol at this point in the game?

Thanks.

[KE4AVB]

Those are accessory positions. On this mower A1 powers the after fire solenoid and the optional hour meter. A2 is lighting. With you moving the wires around it is likely that one of the Packard terminals has a broken spring hinge causing a loose connection.

Now here is a question if you get the engine to start up does it stay running?

[lefty]

Actually, looking at this (photo link attached) There appears to be a couple grey alignment tabs on the switch that don't correspond to anything on the harness plug. Almost as if this is the wrong switch for the plug. Should this be seating up nice and flush?

https://photos.app.goo.gl/28XWL6i4utNhPf7R8

[KE4AVB]

Those are fine. I first time I ran into that I thought that too recently on a switch but the new switch had them too. I don't know why they started add those stops. I reckon it make us to ask questions and by new switches not knowing that it is normal.

532175566 Switch image

[lefty]

Those are accessory positions. On this mower A1 powers the after fire solenoid and the optional hour meter. A2 is lighting. With you moving the wires around it is likely that one of the Packard terminals has a broken spring hinge causing a loose connection.

Now here is a question if you get the engine to start up does it stay running?

I'm told that it will stop during operation. This is a problem that has been in play for a couple seasons. Last year, the owner was able to wiggle the key and get it to operate for a good amount of time. When it would stop, he would wiggle things around again and get more hours out of it. It came to me with some carb trouble today and a service. So I thought I would tackle the electrical problem while it was in my garage. What you describe sounds like it makes a lot of sense. If I were to fix that, are we talking about a whole new wiring harness or is there a workaround. I was gently wiggling each wire on that plug but the terminals don't seem as if they're made to come out.

[lefty]

Trying to find an after market carb for this as well.

Briggs 31H777-0202E1
Serial: 030725Z

I have the one with the Walbro Carb: LMT 0233 697204

I found one for the Nikki but the Walbro number doesn't come up as anything. I can't find a part number. Not sure if it's just me but I can't get to any Walbro site either. I get some weird message when I try to get there.

I need at least a bowl gasket, would like a needle just to be safe. I'll add a shut off as well as a safeguard.

[KE4AVB]

According the IPL that engine came with a Nikki PN 792358 which has been superseded to 594593. Sounds like someone just stuck a Walbro on it.

Okay dying while is a secondary problem. First the terminal is replaceable. It is GM/Delphi PN 2965867. Just the PN for sources. Usually available pks of 25. The secondary problem is that the engine isn't charging or has also a loose connection as it directly feeds the solenoid from the stator (alternator) while the engine is running.

[lefty]

That would actually make some sense. It looks like the nikki has a 90 degree fuel inlet, which would make a lot more sense as it would be pointing toward the fuel tank. The Walbro has a strait inlet that points about 45 degrees forward and the fuel line has to almost double back to connect. Am I correct to assume that you would prefer to see the nikki on there rather than rebuilding the walbro? And does that hold true if it was a cheap after market nikki?

[Skywatcher]

Hi Lefty

Hope you are staying safe and healthy.

These engines came with either the Nikki or the Walbro carburetor, so either will work. If the Walbro carburetor is installed, then fuel line # 791805 which has a 90º bend formed in one end should be installed between the fuel filter and the carburetor. As for the key switch, yes these can be finnicky lottle so and so's. What I have done before now is to completely dismantle them, taking a picture with a digital camera or a smart phone at each stage so you have some reference for how it goes back together.

Wash all the internals out with electrical contact cleaner or brake cleaner, do not use carburetor cleaner as this will dissolve some of the plastic parts. Scrub all the contacts with a stiff bristled nylon brush (a tooth brush can work) and dry with compressed air. Next, apply a thin coating of silicone grease or silicone dielectric compound (NOT RTV SISICONE) to all the contacts and reassemble the switch making sure that all the springs and other little bits all go back the right way around into their respective places. Once reassembled. run a full continuity test between to various terminals to make sure everything is working as it should.

As for the letters on the switch terminals, my understanding is this:

B = Battery
L = Lights
S = Starter
M = Magneto
G = Ground
A1 = Accessory terminal # 1
A2 = Accessory terminal # 2

I believe that one of the accessory terminals stays hot during cranking while the other one does not. If I understand KE4 correctly, A1 stays live while cranking and A2 does not. As this is a 4 position switch, your connections should be: (correction requested if needed, thanks)

Position # 1 Off = M + G
Position # 2 Run = B + L + A1 + A2
Position # 3 Run = B + A1 + A2
Position # 4 Start = B + S + A1

Hope this points you in the right direction,

Sky

[KE4AVB]