Starter Strip

MikeP

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There are some known issues with the 850/1100/1150 starter. I thought I'd post some photos to show how to strip the starter for inspection.

This is worth doing, especially as the symptoms of a starter gone wrong are very much like a dead battery. It's worth checking your starter before you lash-out on a new battery, possibly to find that with a nice new battery installed, the symptoms persist.

An assumption here; you know how to take the starter off the bike.

A starter:

i-TKtXqDj.jpg


First thing to do is to undo the 13mm nut on the solenoid that holds the brush-connection:

i-jtXC44n.jpg


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Then pull the connection to one side:

i-6JJLLcM.jpg


Next, undo the two 8mm nyloc nuts and remove them with the flat washers:

i-88TqBkQ.jpg


You can then prise off the end-cover (an old starter may need some persuasion. Use an old flat blade screwdriver and a small hammer to tap around the flange. Once it starts to move, it usually comes off quite easily).

i-nFCx2w8.jpg


You will then be looking at the two carbon brushes and the retaining spring.

i-4ttnfFK.jpg


The spring is quite strong. It needs to be hooked up to allow you to draw the the brushes out of the recesses. Warning! Try to keep control of the spring. Don't allow it to snap back violently into the plastic housing. The housing is quite brittle and is easily damaged.

i-2r7RhVT.jpg


You can then completely remove the carbon brushes. There are two small spacers above the brushes that are there to protect the soft carbon from damage by the spring.

i-ZT4QWNf.jpg


Next, remove the plastic brush housing and the rubber gasket. You need to remove this to access the e-clip that holds the armature shaft in place. It's under a soft aluminium cap (in the centre here):

i-VFJFJtX.jpg


Gently remove the cap (it's just a push fit but may be gummed-up a bit with grease and dust). Be careful, its quite soft and easy to squeeze it out of shape.

i-45MM8Vv.jpg


You can then prise the e-clip out of the recess in the armature shaft.

i-hhBsXHr.jpg


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There's a washer beneath the e-clip. It might look like part of the casing but it's there and needs to be removed now or you risk losing it when the two parts of the starter body are separated.

i-t5tB3GW.jpg


Now turn your attention to the point where the body halves are joined. You will see two soft rivets, or not (not to be confused with two locating pins). The rivets don't actually hold the two parts together (there's three long screws that do that). If the rivets are missing, the starter has been separated before.

The pick is in the hole where the rivet used to be:

i-cmTK45r.jpg


If the rivets are in place, just take an old flat blade screwdriver or similar and slice the heads off (you may need to poke or pull the left-over bit out).

As mentioned, there are three T25 Torx screws keeping the two parts together:

i-VrNjWvg.jpg


Remove them. Two are long and one slightly shorter. The threaded section of the body is not deep so clean the exposed threads before starting to undo them otherwise if they are gunged-up and you damage the thread, there isn't much of it.

i-7CgKb2x.jpg


Now you can separate the two halves. Note there are two dowels that aid location. You can only pull the halves apart and you may find that there's a fair bit of resistance at first.

i-FTLJVHq.jpg


You can then draw the armature out of the body:

i-TCgBrHw.jpg


There will be some magnetic resistance but it will come out.

On the commutator end of the armature there is a bush and washer:

i-pKJj5DD.jpg


These usually stay put but be careful that they do.

What you will hopefully see inside the body:

i-kFt9C65.jpg


What you don't want is:

i-R47Gp67.jpg


The black clump is the remains of the magnets that have worked loose and wedged the armature (giving the slow churning that's often misdiagnosed as battery failure).

At the other end, you want to see this:

i-3DXLTvZ.jpg


That's the oil-catch plate behind which are the gears.

What you may see on the face of the armature is this:

i-wpNfRrp.jpg


and correspondingly, this:

i-FRnCzmg.jpg


Here the oil/grease retaining plate has come adrift and fouled the armature. At first it's merely rubbed against the armature but it eventually stopped it turning and the short caused the holes to be burnt through the plate.

A short-term fix is to remove the plate and reassemble the starter. It will work fine without the plate but eventually the armature might become too contaminated with grease to work properly or the lack of lubrication in the gears may cause them to fail.

If all looks well, check the carbon brushes are not in need of replacement, clean the inside of the body to remove the accumulated carbon dust (I use brake cleaner, just spray it liberally and then blast it dry with an air-line). Clean the cuts in the commutator and grease the gears and shaft before reassembly (which is just the reverse of the above).
 
cracking post mike , thanks for that .. my starter has just developed in intermittent fault , think it aint throwing the spiggot shaft out all the time , the usual spinning noise with no engagement .. a wee job for the closed season :thumb2:thumb2
 
Great post Mike!
My starter is a bit sluggish and I've been contemplating a starter strip / service - this thread will be invaluable :thumb2
 
Just did this exact same job about 3 weeks ago.

BMW want $950 for a new starter here.

I went to a Valeo service depot and bought the back half of the motor and a complete brush setup from - i think - a vauxhall/Holden - for 1/3 of that price.
 
cracking post mike , thanks for that .. my starter has just developed in intermittent fault , think it aint throwing the spiggot shaft out all the time , the usual spinning noise with no engagement .. a wee job for the closed season :thumb2:thumb2

Thats easy, just the bendix is full of crap, just whip off the stater ansd clean the mechinisan bit of WD and LIGHTLY oil the mech all will be well.
Dave GS (85000 starter stiill going strong)
 
I had starter problems, a few years ago. Replaced battery, still the same sounding like it just wasnt throwing the starter in far enough and on inspection the starter gear was goosed. Replaced starter. And still as bad checked starter ring on flywheel. And the teeth on it, were worn away too, three nights in a cold barn later sh flywheel fitted and no problems since, all within 18,000 miles.
 
Just to say thanks,:thumb followed this thread, this morning, cleaned it all up and have replaced, brilliant,:thumb2 thanks for posting this thread, top man.

It started first time,no probs :D.

Bill. :Motomartin


Ps one thing I let the spring flip out when replacing the bushes, and it hit me in the eye, and it Fecking well hurt, OUCH but I will be ok told my mum she laughed.....
 
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At the other end, you want to see this:

i-3DXLTvZ.jpg


That's the oil-catch plate behind which are the gears.

I've got mine stripped down at the moment as I'm having starting issues. I was surprised to see that I didn't have one of these oil catch plates as it appears that I'm the first to open it up (both soft rivets were in place). Did it disintegrate or were some made without? Attached a picture of mine.

Other question...the main cog on the outer part of the motor, is that supposed to turn while the armature is being held still?
 

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Hi all,
new poster, long term lurker.
I have followed this excellent post and stripped my starter motor to find all four magnets loose, no further damage. Having re-glued my magnets I have discovered it is possible to stick them on the wrong way round with a motor that spins clockwise:nenau Not being sure which way round to stick them (opposite or in pairs) I sought expert help from Rotating Electrics (google search and you will find them Birmingham B33 8UG). Mark stripped and rebuilt the starter motor ordering a new 'magnet housing and magnets' bit all for £35 inc. parts :thumb. He has said that he can supply the 'magnet housing and magnets' bit and will post it. No affiliation blah blah make any arrangements you like with him.
Cheers
 
Great post Mike, I took mine to a local starter and alternator company last week, they did exactly the same as you, except I got charged £20. Not that I minded :thumb

Edit: I just noticed that this thread has had over 3700 views... then noticed it was written 2 years ago, your starter will need doing again soon :D
 
Well I'll be bolloxed :blast

Brilliant thread Mike. :thumb2

Wish I'd seen this a few months ago though. Flat battery my arse !:mad:
 
Edit: I just noticed that this thread has had over 3700 views... then noticed it was written 2 years ago, your starter will need doing again soon :D
That one is a spare I built and keep on the shelf and I have enough bits to build another.:thumb2

I've never actually had a starter problem on my own bike, the parts I have, all come from other people's bikes that I've done work on. :D
 
Excellent post!

Done the job on Friday last, there's a definite improvement even though everything looked perfect.
A tip for reassembly, remove brush retaining spring before replacing bakelite brush holder, then push spring into place when bakelite brush holder is in position on starter body, spring will keep holder in place before putting on cover.
Maybe above is obvious, but you learn from mistakes!
 
I used this info with my starter and as it shows its all straight forward and cleaning it does make alot of difference, I also used the same trick with the brush springs making reasembly a doddle....
 
Just wanted to say thanks for posting this thread. I have a bit of a sluggish starter when cold so I wanted to check everything was OK. Followed everything in here and gave it a good clean. Strangely it wouldn't start when I got it back on the bike (no movement from the starter at all) so I retraced my steps and when it was all back together it worked fine. No idea what caused it!
 


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