Another stupid safety switch question

917.288525 Craftsman.

I bought this off of someone I don't know (cheap). Apparently his dog like chewing on mowers, because he chewed the seat plum off of it. And he also chewed the safety switch wires. I got another seat off an older craftsman that has a two prong switch. There's three existing wires from the mower, Grey, green and black.

Funny thing about all this, is sometime the mower starts right up. Something it just turns over and over. When it starts right up, it now runs great. I mowed with it for about 20 minutes yesterday and had no problems, until I killed it and tried to start it back.

The engine, Briggs 331977 0010 G1, I cleaned the carb. The needle and gasket were fine, afterwards. I can tell it's getting gas, because after a few seconds of cranking, droplets of start coming back up towards the air filter. I thought I first it wasn't getting spark. But I think my spark tester isn't working. Because I touched the wrong thing when I was cranking it, and it knocked the "far" out of me.

Seems to me, that if it was the wires to the safety switch, it would never start. But then again, it starts sometime with them all being cut. Seems like if it was the coil going out, it would die after warming up.

I'm stumped.

For it to start assuming all switches are working. The pto (blades) must be off. If the parking brake is set then seat switch is not in starting circuit. Sounds like you will have to rewire or test each wire to get it working right.

MowLife said:

For it to start assuming all switches are working. The pto (blades) must be off. If the parking brake is set then seat switch is not in starting circuit. Sounds like you will have to rewire or test each wire to get it working right.

Click to expand...

The brake safety switch is connected and working properly. It won't even turn over without the brake pressed. IIRC, that's the way it works with the seat switch too, nothing happens when you turn the key.
With the wires cut (seat switch) the engine still turns over.
The PTO (cable) isn't engaged.

Later on, I reset the coil gap, then tested it with the two new spark testers I just bought (Cheap ones from Amazon). And got no spark in either of them. Put my old tester on it, got spark and it fired right up.

Once again, it wouldn't start. Tried the new spark testers and got nothing. No spark at all. Then tried the old spark tester and it fired right up.

No rhyme or reason.