Starter Randomly Engages while engine idles

[njterrier]

Need help.

Have not used the boat in 6 weeks, boat ran great all season.

Today I went to start the engine (1998 Yamaha 115 2 stroke) on muffs, as I always do before launch. Motor started up “Cold Start” as expected from a 2 stroke. Noticed that the voltage was a bit low while cranking, but built back up to 14.4v after a few minutes. When the voltage did hit 14.4 I heard a clank, then a whirring sound come from the motor. I also noticed that the voltage dropped back down to 11.2v. Turned the motor off, and removed the cowl, and flywheel cover.

Restarted the engine, fired right up, watched the voltage build up again, then at 14.4v – clank, and this time I saw that the pinion gear on the starter had popped up, and hit the bottom of the flywheel, starter was spinning- accounts for the whirring sound. Turned off the motor, and checked all the connections, fuses, and wires around the starter motor and everything looked in order.

I then sprayed some WD-40 into the ignition/key hole as I figure there can be some moisture in the switch. I let the WD-40 drain from the weep-hole, and also sprayed can of air into the keyhole to dry off the WD-40. This worked for a little while, no random starter problems as I continued to test on muffs. Then tried to launch the boat, and had the same problem occur. I pulled the boat back on the trailer, and tried the WD-40 fix again.

Problem occurred a few more times, but his time I wiggled the key a bit as the starter randomly engaged at idle; this caused the starter to disengage.

I have a feeling that the ignition/key switch is going bad (11 y/o).

Has anyone else ever have this happen?

Should I also look at other possible problem sources? Relay? Wires? Starter itself?

Any feedback would be appreciated.

THX

Scott

[njterrier]

Turned out to be a bad ignition switch.

Tested it by disconnecting the brown "go" wire to the starter relay, turning the ignition key to "on", and then testing for voltage at the brown "go" wire at the starter relay. Test showed full voltage going to the relay. Bad switch, as power should only go there when key is turned to start.

Changed the ignition switch, no problems now.

THX Scott