[alumabrian]

I have a gently used 1642 RER. It starts well with the key but will not shut off with the key. I replaced the ignition switch but that did nothing.

ANY SUGGESTIONS? I am not that mechanically savvy so I am sure it is something simple.

 

[kogafortwo]

When the switch is turned off, it grounds the coil. There should be one wire from the ignition coil (under the recoil or screen cover) that goes to the switch, and then from the switch to a bolt or screw on the engine or tractor chassis.

One of these connections is bad.

 

[alumabrian]

Okay so I found after taking the engine cover off that the grounds from under the magnetos were both frayed. I replaced those and put everything back together. Unfortunately now I am not getting any spark.

I had to remove the magnetos to get the old wires loose. I am sure there is a specific gap to the magnetos and the flywheel. Is that the problem or did I do something other than that?

Help my yard is getting taller!!!!

 

[hardknox00001]

Okay so I found after taking the engine cover off that the grounds from under the magnetos were both frayed. I replaced those and put everything back together. Unfortunately now I am not getting any spark.

I had to remove the magnetos to get the old wires loose. I am sure there is a specific gap to the magnetos and the flywheel. Is that the problem or did I do something other than that?

Help my yard is getting taller!!!!

I would take the small wires loose and see if you get a spark then. If the engine starts, touch the small wires back to where you bolted them. If the engine stops, the wires are not routed through the switch correctly. The switch "breaks" the small wires from ground so the coil will produce spark. When you turn the switch off, the switch completes the circuit of the small wires and removes the spark for the engine to stop.

 

[alumabrian]

Are there wiring diagrams available for Snappers?

My thought then is someone before me rerouted or changed a wire somewhere. It would be nice to know where the wires were supposed to be in the first place.

Here is another thought. I did use a thicker gauge wire to replace the two grounds on the magnetos. Would that cause a problem?

 

[hardknox00001]

The guage of the wire doesn't matter. Guage only matters when you start thinking about how much current you are trying to carry, ie battery to starter = big wire (low gauge number like 2 awg), common circuitry wire where loads are not large = smaller wire (higher gauge number like 18 awg).

As far as wiring diagrams, you might go to the snapper website and click the manuals link and enter your model number in the box and see what you get. I have noticed lately that they do not support their older models like they used to. Several years ago, I downloaded my manuals from there but now none of the manuals for any of my mowers are listed anymore. If the website doesn't do you any good, I guess you will be looking for someone on here that has one and would be gracious enought to make a copy or your looking on ebay.

With that said, magnetos are not extravagent in their wiring. The big wires go to the plugs, the little wire is the ground lead, that's it. Unless you have something I have not seen before......I haven't looked to see what a 1642 is but I have a RER that had the 8hp motor on and when it self destructed, I put on a 13.5hp and it still only had a spark plug wire and a ground.

Just thinking a little, sometimes the alternator wire (mine is dark blue) and the mag ground (mine is black) can be confused, and then there could be an extra wire off the engine alternator for headlights (mine is white) and because the mower isn't equipped with headlights I just capped it off with a wire nut and put that in my brain as "for future expansion" , so physically tracing wires back to the source is always a good thing.

 

[Boyd]

When desperate find a thin piece of wood to pry the spark plug wire off. Or cut a piece of hose and put around a screwdriver,, then pry off the spark plug wire.

 

[alumabrian]

Well let's go back to the beginning.

The mower was running and starting fine, when the battery had a charge. I would pull start the mower, mow half the yard, shut the mower off, and then have no problem restarting with the key ignition.

When I shut the mower off I had to either cut off the fuel or "choke" the engine out. If I used the key switch to shut the mower down, the engine would just (lower) rpms but not shut off.

So far I have replaced the ignition, and the - batterry terminal wire, as well as the main ground from the solenoid to the main ground on the back of the engine. Someone then suggested there was a short in the engine somewhere. So sure enough when I took the engine cover off I found that the grounds from the magnetos were both frayed and one completely cut.

I am assuming that the one that was cut was causing the dip in rpms when I turned the key off. The other one was trying to shut the engine down but couldn't. Now that those are both replaced, I have no spark.

I certainly appreciate the help.

 

[Rescuemo]

The gap between the coil and the flywheel is very narrow, paper thin. Many times I have just used a dollar bill between them to set the distance. It doesn't take much to cause the engine to lose spark, so check that gap first. I had a Briggs engine that had a tendency for the coil to work loose and move further from the flywheel, and it would die in the middle of cutting. Recheck your wiring, and see if adjusting the coil's distance (again--paper thin distance from the flywheel) makes a difference.