72 panther with a 292 single electrical question - Snowmobile Forum: Your #1 Snowmobile Forum

emrides · 01-17-2013, 05:30 PM

I have an old 72 panther with a 292 single. I'm trying to make sense of the electrical system (some bonehead pulled it all apart - cut wires, no battery.) Out of the motor, it has got two yellow wires and a black wire sticking out (it's an electric start) I read around 10 volts ac coming from each of the yellow wires at idle. From my wiring diagram I understand these wires go to a voltage regulator, which I misplaced somewhere (great) and I will have to re-purchase. Any suggestions there? I am thinking a generic electric start voltage regulator if I can get away with it, although it seems the one that came with the sled had a (25 amp?) fuse, I suppose I could wire in a 25-30 amp fuse right? Anyway, the black wire is supposed to be grounded and there's a green wire that grounds the regulator and a yellow/black wire that goes to the b terminal on the ignition switch and another yellow/black wire that links to the positive battery post. So... The black wire which is supposed to be grounded bonehead linked up to a switch which when thrown kills the engine - the switch grounds the wire (and coil I assume.) I checked this, with the wire just hanging out motor not touching anything, the darn thing runs but ground that thing? Yep, it sparks and the motor quits. That can't be normal right? Or is it. Do I need to ground this wire to hook up a battery, voltage regulator and lights. Does the lighting coils somehow integrate and allow for running and normal shut off? What's going on?

**RJ Gleason** · 01-17-2013, 11:17 PM

Nope, that black wire is the ground for the ignition and should be connected to the key and kill switch or tether.
The rest of the system [lights and battery] ground through the chassis and to the motor.
It is a very simple system to wire up.
Both yellow wires must connect to the regulator/rectifier first and then to the switches and battery.

emrides · 01-18-2013, 02:14 PM

So the black wire coming from the engine which you say is the ground for the ignition, is correctly doing its job? When grounded, it shuts the motor off. Is that what you're saying?

-and also, thanks for the quick response.

curtludwig · 01-18-2013, 09:19 PM

Thats exactly right, grounding that wire is how you turn the engine off.
The kill switch and ignition switch are normally open switches, so you run them to that wire and to ground so when you flip the switch it grounds the wire and shuts down the engine.

emrides · 01-24-2013, 02:11 AM

Thanks for that confirmation.
Hey, I replaced welch plugs (finally) in the carb according to you deadsledwrencher.net site and the thing runs like a bear. All this is after buying a new carb for the the darn thing. It came with a carb which looks it was off a 72 EXT - #HR109a, although, my service manual says EXT's have a pair of 'em. I bought an HR70B which looks almost exactly the same really, had to rob a choke shaft off the older carb and ball and spring off another so choke stays open and closed. Probably should've just did the welch plugs on the original carb but I didn't know it was that important of a service until I read you site. Maybe I'll rebuild the other carb to see if there's a performance enhancement, although I seriously doubt it, the only difference seems to be this bit of brass cover over the little horn-like protrusion in the main opening of the carb. I guess thats where the gas shoots out of feeding the motor. Maybe it would atomize the fuel better? I sometimes ponder (but not for long) rigging up some manifold to have both carbs feed the single, probably would blast my motor to bits and would take some serious effort on my part. It'd be easier to get an HD to HR kit, the other carb being an HD60A carb which appears to be off a various JLO's, that way I could have crappier gas milage...I think I'll leave well enough alone and maybe ebay the spare carbs. Tracing the wires and maybe getting the thing to start via electric starter is gonna feel like enough work I'm sure. Thanks again for the info.

curtludwig · 01-24-2013, 08:53 AM

The different numbers indicate different jetting in the carbs. I presume there is a master list some where of what jet sizes you get with which carb, or maybe theres some code in the number but I've never seen it explained. Generally sleds run best with the carb they originally came with.

Ski-Doo's Super Olympique had a dual carb on a single cylinder at one point, I can't remember the year but mid to late '60s anyway. Actually my Husky chainsaw has 2 throttle plates, at high revs the second throttle plate opens to provide more air, it doesn't add more fuel though.