Strange noise when using starter, CB550 K3

[Pasoren]

I have a strange noise when using the starter, but not everytime.

Does anyone know if the starter is worn, or worse, the starter clutch??

http://youtu.be/D5kzgiQlOsk

[Piki]

Me too

[Johnwebley]

I don't know,but it does sound like dry motor bearings,
the noise is as the motor is un-loaded,and slowing down,

 try removing it,and running it ,if you hold it ,you should be able to feel that vibration,

[Lobo]

...I'm with John, 99% sure it'll be due dry / damaged bearing(s).

When the motor is cranking the starter shaft is loaded / pushed hard against a circumferential part of the bearing and subsequently cannot 'rattle'....once unloaded it is no longer constrained and will 'rattle' in the worn bearing - hence the noise.

You might get away with a good dollop of lubrication... but likely a short term fix.

(I'd expect an unloaded bench test in your hand to rattle too.)

Simon.

[deltarider]

Bendix withdrawing too slow?

[mike the bike]

The starter doesn't use the bendix gear principle,  It's permanently engaged (sort of) using 3 roller clutches to drive a starter gear when the starter is operated.

[matthewmosse]

Sounds to me like the starter is staying engaged possibly, had it on our landrover once or twice too, think one of my 500s or 550s has done it a few times intermittently , but I have never had a sohc starter motor fail on me, despite abuse. I know the sound well, but cannot point a finger at the exact cause with cirtainty, on my bikes it has worried me then gone away with no actual known fix or dammage.

[JamesH]

Yeah it's the sprag clutch withdrawing too slowly I reckon. Experienced exactly the same noise on a cb450 k7

[matthewmosse]

Thinking more about it, I think a few decent oil changes sorted mine, the kind of thing that hondas do to tell you the oil is low or poor. My first 500/4 had oil like tar and the starter either did that or spun without engaging when I first got it, only intermittently but after about the 3rd oil change it got super reliable on the starter and I no longer had to resort to bump starts ( kick starter rounded off too) good thing it started easily.

[Pasoren]

OK, thanks for the input! I will try lubricating the bushing in the starter motor, and if it helps, I may get a kit to refurbish the motor.

I can probably borrow another starter motor to test. Will try the easy things first!

Thanks!