Briggs V-Twin electrical problem

[Chuck52]

I tried searching for threads about electrical wiring, electrical problems, etc, and didn't find anything useful, so if anyone knows of previous applicable threads please point me to them.

My MTD rider, with a 21hp Briggs V-Twin started just fine Saturday and ran about 20 feet. It then died as if the plug had been pulled, and though it cranks strongly it doesn't even burp. I figured one of the wires the mice had chewed earlier had proven tempting again, but there doesn't seem to be any more damage than before, which I fixed with electrical tape. The electrical systems on these things is a mystery to me....I don't know where the spark even comes from! Is there a coil, or a coil substitute that could be dead? I'll be tracing the wires to see if the rodents found something new to eat, but the fact that it cranks eliminates such things as the seat safety switch, doesn't it?

Chuck

 

[mostly_gas]

Just went through this with neighbor 18.5 Briggs. There is a wire on the coil that grounds out the ignition. Removing this wire will remove any problems with mower wiring. Check for spark. If no spark and ground out wire removed, it is time to troubleshoot. Air gap between the steel laminations and the magnet in the fly wheel s/b .010-.014 and no rust on magnet and coil assembly. If still no spark then coil is probably bad. If you get spark with wire removed, then you have a wiring/safety switch issue.

 

[Chuck52]

Thanks for the reply. If it's not that wire, it's probably another....just gotta get to all the wires and run them.

At least it's better than my friend's troubles. I was telling him about my machine because he has the same thing except it is labeled Troy Bilt, and it has a few more bells and whistles. He said a couple weeks ago his wife came in from mowing and said the mower was making a lot of noise so she shut it off. He checked it out and it was smoking, even from the oil fill tube. Seemed to have no oil, so he filled it and it started right up but was clanking a bit at first before it settled down. Then his wife asked him what the liquid coming out the side was. He pulled off the side metal and saw a hole in the side of the engine casing with oil pouring out! He let it cool off, then cleaned the area and stuck the piece of metal that had cblown off back on with a goodly patch of JB Weld. He says it still runs a bit rough and has lost some power, but he's mowed with it that way for a month.

Chuck