Seized Starter Motor?

[Scrap]

I've not been riding much over the last few cold and rainy months and my 2008 ER6 has started to have issues starting.

Key on, side stand up, neutral. Push starter button; “Click”. Starter motor doesn’t spin.

Keep pushing the starter, and each time I push, the starter relay clicks. Note, it’s a single click and not the rapid clicking which I’ve had before with a duff battery.

Eventually, after about a dozen presses of the start button, the starter turns and the bike fires up within a crank or two.

After stopping for a lunch break, the bike fires up again first time. But leave the bike to stand a day or two… “Click”

I’ve eliminated;

- Battery and charging system – Voltages are good, and the bike starts – eventually. I’ve had issues with the charging system recently and by now the stator, reg/rec, battery and all the wiring and connectors between have been replaced.

- Starter relay; works fine, sends voltage to the starter motor as expected when start button is pushed.

- Wiring and grounds, looks alright, at least from visual inspection.

- Clutch, side stand and kill switches, makes and breaks as expected, showing expected resistance when the switch is closed. Anyway, the starter relay shouldn’t even be clicking on if the side stand or clutch switches are stuck open or have overly high resistance.

Given this info, I’m thinking seized starter motor. I suppose this makes sense given the hardly-ridden-bike has been sat outside in the rain for a while.

I’m not particularly experienced with this sort of work, what are your thoughts?

Before I buy and fit a new starter motor, is there something else I should check?

[WD Forte]

Assuming the battery isn't fooked
A
I'd check and CLEAN all cables/terminals to the motor and grounding
B
As its 2008 bike, I suspect it may just need new brushes and the commutator cleaning up

Voltage is just voltage and doesn't give the full picture
Voltage with little or no current due to poor contacts
has little or no power.
Voltage doesnt turn the engine, power does.
____________________
bikers smell of wee

[dynax]

Take it off, strip it down and clean it, have a look for a refurb kit for it, pointless buying a new one when they are perfectly serviceable
____________________
Mike.
Bikes: Xena, Bridget,Florence
https://www.youtube.com/channel/UCmihUc0xXxYbR4_0l-F1FzA/videos?view_as=subscriber

[steve the grease]

[davebike]

I expect either worn out or sticking brushes !
____________________
Dave
NC750Xdct + others at work !
davebike1@gmail.com

[Robby]

I also think it's the brushes. They're usually cheap for a pattern pair, so I would order a set before pulling the starter motor off the engine.

Changing brushes is one of those jobs that's very easy if you do it right, but also possible to swear at it for hours and only just get it done if you do it wrong. I recommend watching a youtube video on rebuilding a bike starter motor before you pull the old one apart.

[Scrap]

I'm reasonably confident it's not the battery.

I suppose we have a consensus of opinion; that is not to replace the starter but to refurbish it; lube shaft, clean or replace brushes, and clean the commutator. While the bike's apart, I'll inspect and clean the conections between the battery, starter relay and starter motor.

Right, that's a task for the weekend.

Thanks for all the comments, I’ll report back with results soon.

[Courier265]

[sickpup]

Quick and easy way to tell if its the brushes.
When it doesn't start put it in gear and rock it backwards so the starter clutch engages and turns the starter motor backwards. If it then starts it's the brushes, if it doesn't after a couple of attempts it probably isn't.

[KiwiBob]

Whip the starter off .. take it to bits and give it a clean.

https://www.youtube.com/watch?v=CrYbQ6OkU0Y&t=561s

[Scrap]

Thanks again for all the comments. I serviced the starter motor and the bike is firing up first time again!

I took apart the starter motor down to the individual brushes and springs, pulled the armature out, and gave every surface a brush- and wipe-down to remove as much of the powdery build-up as I could. Smeared some bearing grease on the bronze bush on the rear cap and left the front cartridge bearing alone, doesn’t feel dry or crunchy. Commutator bars got a good scrub with electrical switch cleaner.

Nothing felt seized to me, all the brushes, springs, bearings, shaft etc moved normally. Brushes according to the Haynes manual start at 12mm and have a minimum spec of 6.5mm, I measured 10.8mm on the most-worn brush. With 55k on the clock and 20% wear on the brushes I wasn’t motivated enough to get the soldering iron out, so I left the existing brushes in.

Springs all felt good and there was a good amount of springiness putting the brush cap back on so I know the brush springs were doing their job.

I suppose the most likely cause of the non-start issue was the commutator contact surfaces becoming oxidised from inactivity.

Also, for future reference. The throttle body doesn’t need to come out on an ER6 to get the starter motor out, a UJ socket adapter helps.

[steve the grease]

Nice one . No greater sense of satisfaction than fixing something yourself.
____________________
All the above is my personal opinion, you can see my lips move, but I'm talking out of my arse.
I've been riding, and fixing , bikes for 50 years, in that time the more I learn, the less I am absolutely sure of.....