I replaced the motor in my 13 year old Honda lawn tractor with a brand-spankin new one. With some trepidation I turned the switch and that baby started right up and purred like a kitten! The problem? It wouldn't turn off! Using the switch was useless. The only way I could turn the mower off was by stopping the flow of gas to the carb. I cleaned all the leads on the switch and still it doesn't turn off. Any comments are welcome...

The engine is shut off by grounding out the coil. There is a wire running from the ignition switch to the small wire that goes up and under the metal engine cover. Make sure you have hooked up this wire.

That's the thing. The only wires connected to the original engine were those running to the starter. I matched those up to the starter on the new motor, but there are a couple of additional wires coming from the engine on the opposite side of the starter. I have no wires from the switch or chassis that could possibly match up with those wires (I suspect they may be low-oil alarm leads). Also, with the motor off, I can hear a slight clicking sound (relay?) from somewhere under the body of the mower, so I know turning the switch off is doing something...

Did the engine plug wires match on the new one
What color are the two wires

The new engine came complete with a new carb, sparkplug, starter motor, etc. (No need to mess with the plug wire) I simply installed the new one motor assm, hooked up the starter and fired it up. The two leads to the starter motor were different colored than the original, but the motor fires right up even if I swap those leads.

Hi,
How about the engine model numbers. Should be one silver sticker on the side of the block.
Peace,
Clarke

You said there were two wires not hooked to anything what color are these.

Many thanks, DG and Clarke. I pulled the cowling off the old engine and found the ground wire to the coil you mentioned. It was routed differently (around the starter side) than the wire on the new motor. I pulled the cowling off the new one and found its coil wire had been routed down the carb side (the two extra wires I mentioned earlier were actually this one, but for some reason they have split it into two connectors). I re-routed it similar to the old one and connected it to the proper grounding wire. Now my new engine starts AND stops perfectly. Thanks again! Mike

Sorry, forgot to mention you, too, JS. Thanks for your input!

Glad you got it fixed Cheers
DG