GT550 Borg Warner starter clutch

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barney01
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GT550 Borg Warner starter clutch

Post by barney01 »

I have been trying to fix my electric start problem for 10 years and just want to pass on what i have learnt.
About 15 years ago the starter motor started spinning on its own without engaging the starter clutch, especially from cold. I initially suspected it was electrical not enough power to the motor. So I changed all the power and earth cables. I cleaned a very dirty solenoid and start button. I checked the power supply to the motor with a multimeter and no problems with power supply.
Next i removed the clutch all appeared okay but in closer inspection i saw that some of the teeth in the one way starter clutch bearing were loose.
The way this bearing works is at rest the specially shaped teeth grip the starter clutch gear wheel which is turned by the starter motor. When the engine fires and the clutch spins centrifugal force pushes the teeth outwards against a spring releasing the connection between the starter motor and the clutch.
So i tracked down a NOS and very rare starter clutch bearing in the US (£50) and to my dismay after fitting it the same problem.
All this time the bike was on the road and being used daily, i just used the kickstart.
So a few months ago i bit the bullet and bought a complete Borg Warner clutch. As soon as it arrived i knew that it was going to solve the problem.
I fitted it yesterday and bingo. So i have read bulletin GT26 and there is a small paragraph
which says you cannot mix and match three vital parts they must come as a set. 1. The starter drive gear. 2.The clutch basket and 3.The spacer shaft that connects the two. Otherwise the starter will fail.
So the moral of this long story is only buy a complete clutch as trying different component parts wont work.
https://youtu.be/CFQKB2kkVWY
https://youtu.be/Gl_6BGkRlMw
Last edited by barney01 on Sun May 24, 2020 2:33 pm, edited 1 time in total.
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Alan H
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Re: GT550 Borg Warner starter clutch

Post by Alan H »

If you'd have asked, Barney, I have spares - and so does Reiner.
Proof that four strokes are over complicated
barney01
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Re: GT550 Borg Warner starter clutch

Post by barney01 »

You have a 'spare' borg warner? I know someone looking for one desperately. :D
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barney01
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Re: GT550 Borg Warner starter clutch

Post by barney01 »

Just copying a link from Sundial very usefull info for bearing replacement. Reiner in Germany has no stock of this size bearing
http://www.suzuki2strokes.com/forum/vie ... =9&t=14299
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barney01
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Joined: Wed Sep 26, 2012 7:33 pm
Location: Prestatyn.Wales

Re: GT550 Borg Warner starter clutch

Post by barney01 »

So having spoken to Alan H and Reiner in Germany i found that there are TWO sizes of Borg Warner one way starter clutch bearing.
The smaller(and more common) is 13.5mm deep and the larger one is 15.7mm deep. Reiner had no stock of the small but plenty of the large. When i measured the recess in the back of the clutch i got 16.5 mm. Having thought i had solved it i ordered the bigger one.
When it arrived i realised i had measured to the surface and not to the retaining circlip. Bugger! Too big. So its on its way back to Germany and i am back to square 1 :lol:
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The two different size one way starter clutch bearing
The two different size one way starter clutch bearing
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Alan H
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Re: GT550 Borg Warner starter clutch

Post by Alan H »

A very well kept secret!
Reiner told me a couple? of years ago and I needed the thinner one as well which is nla. Can't think that Borg Warner only made that specific size for the 550, but BW don't seem to recognise the size, spec or anything else about it.
Someone on Sundial posted about it a few days ago, but nothing found searching using their numbers.
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barney01
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Re: GT550 Borg Warner starter clutch

Post by barney01 »

Alan i have been phoning NSK europe and the bearing is on their system but the automotive section is in China. Eurpoe deals with engineering bearings. There main dealer in the UK is called Bammer and in Cumbria. Apparently it is possible to get one but it takes 8 weeks.
I have given info to Reiner maybe he can get some
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yeadon_m
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Re: GT550 Borg Warner starter clutch

Post by yeadon_m »

Barney,
This is all v interesting as my 550 later starter clutch has never been too clever. I thunk I have the correct type on it’s way from Marcel, but you’ve thrown doubt in my mind as to the width.
I did go through NSKs catalogue but I only found the too wide one.
If you had access to a machine shop, could a circlip groove be made to accommodate the wider device?
Cheers,
Mike
barney01
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Re: GT550 Borg Warner starter clutch

Post by barney01 »

Hi Mike
Good to hear from you. The simple answer is no. The bigger bearing will fit but it is exactly flush with the basket face. Then when i looked at the starter clutch gear wheel i saw that the surface the bearing runs on is actually the size of the little bearing.
I have removed the bearing from my defective clutch and washed it thoroughly in parrafin and it seems to be working now? Cant be sure inless it's on the bike of course but by hand it is now working.
There is some information out there that suggests these clutch bearings are sensitive to debris in the oil and as there is no filter....
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2020-06-05 14.09.47.jpg
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Alan H
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Re: GT550 Borg Warner starter clutch

Post by Alan H »

I did similar on the Earwig in diesel, then petrol, and put it all back together and it worked fine - 2 years later, it's still ok.
Possibly the po used a synthetic or semi synthetic gearbox oil which caused slip? The clutch used to slip too until I fitted new plates, springs and an extra steel plate for good luck!
Saying that, when Baz & I stripped the engine to do the crank last year, all the 4 gearbox bearings were shot, so we replaced the A gearbox with a spare B one that happened to be in the stash, so whatever 'lubricant' had been in there had been fairly crap......
Proof that four strokes are over complicated
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