Starter motor clutch

[Barney T Weasel]

Has anyone ever had a starter motor clutch jam on at speed and spin up the starter motor, slowing the bike dramatically? (Back wheel squealed for a sec) Something spun up with a loud whirring noise on mine recently and was still running at idle, so I shut it down. Hit the starter button, dimmed the dash lights and clicked the solenoid (new one) but nothing. The motor still turns over freely by the kick starter but haven't had it started since. Any ideas? Thank you NakedWingers.

[olchris]

IMO it sounds like and electrical issue. Maybe a soleniod wire had shorted out.

To check wiring.... Disconnect the two solenoid wires at the solenoid and get your fav screw driver and, with ignition on and "short out/jump" the two terminals on the soleniod ...

If it starts normally and runs OK with no additional noises, then thats good............. Then Reconnect the soleniod by its wires and try tostart as per normal.... If you detect abnormal clicks and noise and starter "over-run" then there most likely an issue in the wiring..

You will isolate the "electrical" problem if it exists in either the wiring or soleniod ..... or maybe decide its mechanical ...

If all that fails to give a suitable result, remove the diode (1 off 2) eg, the one that has the yellow/red? wire connected and then retry... I had similar issues with starter and removed the diode and now 30+ starts later (on the lift table) and running all seems fixed "without" the diode ... I dont know why and im still unsure but it "behaves" normally...

[rcmatt007]

the way a sprag clutch works would not seem to allow it to jam on like that. As mentioned, a stuck starter relay would. When you say "but nothing". I take it to mean the starter did not even turn (or was it a whirr but no start). When you say it jamed on at speed, was the nose where the stator is? Then I would worry you may have a loose armature in the back of the engine.

so kind of need more info on exactly what and where of what happened

[Whiskerfish]

Agree with rcmatt007 first thing to check is the stator bolt.

[Barney T Weasel]

Thanks for your input everyone. I haven't yet pulled off the starter motor, so will do that soon. The solenoid clicks but wont start the electric motor and I also did a direct coupling of jumper leads to starter & nothing. I thought at first that it may be a "spun bearing" in the engine. Had that sort of feel, as the starter motor wont work...who knows. Will dig deeper. Thanks anyway.

[rcmatt007]

the sprag clutch is a little different than a bearing even though it has rollers. the centrifugal force of the starter turning pushes the rollers outward which then engages the outer part of the alternator which turns the engine. This is why you can push the starter when the engine is running, and it will spin, but won't effect anything. These rollers do have a propensity to get gummed up (especially in an engine that sits a long time) but then you get a whirr often followed by a clunk when you take your finger off the starter button.

Hard to know from your description, but if your engine was already running and THEN you heard something, it is not the starter motor. Even if the relay suddenly shorted giving power to the starter motor, turning the engine off would not stop the starter motor from turning.

It sounds like something happened at the alternator. My hunch is that the bolt that attaches to the outer part of the alternator (which attaches to a shaft in the engine) has come loose. There is a 17mm cap on the back of the alternator cover to access this bolt. It is a 12mm bolt. Many of us use this bolt to turn the engine for timing purposes. It is quite possible someone turned the engine in such a way as to loosen the bolt.

IF this is loose, my recommendation would be to pull the engine, remove the rear case, and there will be most likely damage to both of the alternator halves and they will have to be replaced.

[Barney T Weasel]

Thank you rcmatt007...I shall delve deeper.