starter motor question?

[andy230]

Hi guys,

Can you help me diagnose a starter motor problem please?  I have never had a starter apart, or had much trouble with them, car or bike.  But I get the principles of how they work

The skorp hasn't run for almost a year.

I put oil in today, and needed to crank (and run) the motor to finish the oil fill.

No probs, starter turned as expected.  However, after a bit of cranking, I stopped.  Thumbed the starter again, just a click. 

The solenoid is clicking hapily.  Adding another 12v in parallel only gives stronger clicks.

12v directly to the starter makes no difference.  Still nothing.

So I put the bike in gear & rock it, moving the starter backward & forward (in fact, I dont think I can move it forward, that only turns the engine I think).  But I can definately move it backwards.

After this, I can either thumb the starter or put 12v directly to the starter and it cranks.  After a session of cranking, it appears inoperative again.  When inoperative (but pressing the button, or direct 12v) it does not draw any appreciable current.

Is my starter on the way out?  Does it sound like its a stripable-and-fixable type problem?  Gummed up?  Brushes?

Does anyone know if these are rebuildable or available for the 660 Yam motor?

Cheers for any info!

andy

[themoudie]

Good evening andy,

Thas the problem without the old pogo lever on the side! 

This may help, microfiche of starter motor: 660_starter_diagram

I suspect that the commutator needs a clean and de-carbon from between the segments, the segments may also have Cu2SO4 on them from damp storage!    A new set of brushes or a dismantle and clean, to get rid of glazing, or seizing in their holders etc. A check and clean of the earth strap and all the terminals probably wouldn't go amiss either.

Give Slipstream a ring for a 2nd hand motor removed from a race bike.

New bits from your friendly Flitwick, or Fowlers, if you want OEM parts or Wemoto link: Starter_brushes

NB: SteveH will move this to the correct string on the site!!!! He's nice and tidy like that!  Thanks for looking after us SteveH.

My regards, Bill.

[Andy M]

Start by taking a jump lead and going from the starter motor body onto the frame or battery negative. I had the Bonneville starter motor doing this when the earth connection went. Corroded main battery earth to frame cable meant the engine case wasn't a great earth and the starter motor only hanging off part of that had no chance to pull the sorts of current it wanted.

Andy

[andy230]

Andy, very good point, I hadn't thought of this.  I had just assumed that it was earthed (tho when I think about it, there is a separate earth strap...)

Bill, thanks for the advice, and very useful pic.

I will do as you say, and report back!  Motor off over the weekend hopefully, little boy permitting.  (Or helping??!)

cheers

a

[themoudie]

Aye Andy,

Have fun and watch out for rising groundwater, I believe your aquifer is full up!

My regards, Bill.

[andy230]

Hello,

I am a bit of a fool- my XTZ manual has a very good 3 page section on the starter motor, including electrical and dimensional data!!  However, thanks for the info.

I dismantled it and cleaned everything up.  Not too bad really, plenty of carbon about, and grot on the outside, so thats all gone.

I thought I had found the problem with the very stiff brushes.  Springs were good but the carbon brushes themselves were all quite stiff in the little holders.

Cleaned them all up, and confidently re-assembled.

Bench test- nothing.  No sparks, no current, no jumpy-jumpy whirry motor.

Bugger.

It turned nicely by hand.  And in theory it should work.  Is it really getting power??  (Normally a hefty spark when bench testing, no?)  Apart again!  Continuity test between positive terminal and positive brushes showed 1.3 M. ohms.  Now as I say, I've never had a starter apart, but that can't be good.

Corrosion between the post, and the little insulated + contact inside the casing.

Cleaned it up, 0 ohms resistance, reassembled.

Sparky-sparky, jumpy-jumpy, whirry-whirry.

So you were nearly right, Andy.  I wouldn't have thought this, but the bike has sat for a while...  Just goes to show you how "not good" it is for a thing to sit unused.

Next weekend- running maybe?  Newly matted bodywork on, and maybe a photo?

Thanks for the help,

a

[themoudie]

Hooray for Ureaka! 

It's that medical training and the thought process.

I spent the Saturday dismantling dodgy handlebar switches that were intermittent and then re-assembling same. Finally got the Bros to run, but blew holes like a cheese in the front of the silencer box!  So now for the stick welder and some plate.

Nonetheless, good run out to Dundee, Tayport, St. Andrews beach and Cupar on the SRX and Bros, afore arriving home after a lovely, clear, cool, sunny day in a ruddy sleet shower! The joys of motorcycling and I love it. 

May your wheels soon turn. Bill.

[Andy M]

Nice one 

You should remember this when it's a nice day and people start planning non-biking activities for you. Got to keep the machinery in use or it'll seize up 

Andy