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Why does Yamaha build engines around the starter clutch?

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Nobby the Bastard
Harley Gaydar



Joined: 16 Aug 2013
Karma :
PostPosted: 19:09 - 09 Sep 2015    Post subject: Why does Yamaha build engines around the starter clutch? Reply with quote
As I'm sure quite a number of you know, my FZR 1000 exup is a strong bike, but it's plagued with a knackered starter clutch and a desire to keep the middle east rich with it's thirst for 10/40.

So when I returned from the fabled bbq, off it went to my friend's workshop for a strip and rebuild.

So, engine out

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150815_130621_zpsodx5wgvm.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150815_130606_zps1qgqnnxs.jpg

When he removed the carbs, he found out why it tended to stall when hot...

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150815_145505_zpslixz0prk.jpg

Head and pistons off

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_145019_zpsvf4bhpkg.jpg

Diirtyyy sump...

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_145351_zpsgl28zcxy.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_145354_zpsuc2vim9t.jpg

Behind that is...

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_145826_zpsazjemwdt.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_145829_zpsgumvot7s.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_145833_zpsinsvjpiy.jpg

Looking reasonably clean in there...

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_145912_zpspxi21nc3.jpg


Let the dog see the rabbit...

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_163141_zpsqvvn56jo.jpg

There the little blighter is!

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150816_163144_zpsh0lxk87m.jpg

Shell bearings surprisingly good for a 40k engine

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150817_175416_zps45scvebt.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150817_175422_zpsoaoqnto9.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150817_175425_zps3l21htca.jpg

Head apart...

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150901_182006_zpsoutlgj0u.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150901_191214_zpsuteolifq.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150901_193344_zps5qgggha0.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150901_193351_zpspgdibdfd.jpg

Now, the rebuild....

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150817_175901_zpssa6hhgu0.jpg

New valve stem seals. The old ones were a bit ropey and were no doubt adding to the oil consumption.

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150825_192738_zpsbo6ueodm.jpg

Wrong fucking gasket! Fucking pattern parts... Genuine Yamaha was the best part of £40

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150825_192940_zpsmwh3mucy.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150825_192945_zps8rgzog8h.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150901_182006_zpsoutlgj0u.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150901_200148_zpsefz09ede.jpg

Barrels rough ed up slightly, they were too shiny, apparently. brand new rings added. Further reasons why oil usage was making me a pauper. Crap running in blamed.

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150903_184003_zpslihaubmx.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150903_184022_zpsw63jurby.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150903_184043_zpshnebc2oe.jpg

What the fuck is this shit?

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150905_113530_zpsbkfh0siw.jpg

Engine back in

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150906_133839_zpsichxxtej.jpg

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/exup%20rebuild/20150906_145723_zpstbhgonb2.jpg

Then it started. And it the engine sounded sweet . .... . apart from the ticking/knocking noise which we couldn't identify a source for and so it was turned off again.

Sump, clutch, oil pump etc was removed so the gearbox could be checked (all fine) and my mechanic was resigining himself to a complete strip and rebuild to find the issue.

Later that evening, it dawned on him that it sounded just like the tick that the clam chain tensioner makes when adjusting. It appears that the ratchet on it isn't working properly when it's positioned for a brand new unstretched cam chain.

Currently awaiting a new sump gasket so we can proceed further and check if the assumption is correct.


The mighty exup will live again!
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Suntan Sid
World Chat Champion



Joined: 07 May 2009
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PostPosted: 11:30 - 10 Sep 2015    Post subject: Reply with quote
Bet you're glad to get that starter clutch sorted.
I'd have been worried every time I went anywhere that it would eventually pack up altogether.
Have you ever had to bump it and, if so, did it start?
Bet you can't wait to hear it howling properly!
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Nobby the Bastard
Harley Gaydar



Joined: 16 Aug 2013
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PostPosted: 17:26 - 10 Sep 2015    Post subject: Reply with quote
Suntan Sid wrote:
Bet you're glad to get that starter clutch sorted.
I'd have been worried every time I went anywhere that it would eventually pack up altogether.
Have you ever had to bump it and, if so, did it start?
Bet you can't wait to hear it howling properly!



To be honest, it always started eventually, I've never had to bump it first thing. It was easy enogh to bump when warm.

I'm getting seriously fucked off with getting the train so when I hear it howling, I'll be on it doing the Bristolring...
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Acemastr
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Joined: 01 Oct 2008
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PostPosted: 20:34 - 10 Sep 2015    Post subject: Reply with quote
Roughed up barrels seems wrong on every level to my mind, but then I'm definitely no expert... thought they needed to be a smooth as possible
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sickpup
Old Timer



Joined: 21 Apr 2004
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PostPosted: 20:56 - 10 Sep 2015    Post subject: Reply with quote
Acemastr wrote:
Roughed up barrels seems wrong on every level to my mind, but then I'm definitely no expert... thought they needed to be a smooth as possible


Shouldn't be smooth, should be at 45ish degrees. The roughness helps tp retain oil in the bore but horizontal lines will promote excessive piston ring wear.
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Ben90
Brolly Dolly



Joined: 06 Feb 2014
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PostPosted: 21:02 - 10 Sep 2015    Post subject: Reply with quote
Acemastr wrote:
Roughed up barrels seems wrong on every level to my mind, but then I'm definitely no expert... thought they needed to be a smooth as possible


The new rings quickly wear most of it down. The cross-hatch pattern you can see in the cylinder photos is intentional - even down to the angles of the hatch; it creates channels for the oil to work around. The ideal is to get the rings to sit entirely on a film of oil so practically no wear occurs.

Perfectly smooth cylinders wouldn't retain sufficient oil, or so I understand.

Edit: beaten to it Embarassed
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Nobby the Bastard
Harley Gaydar



Joined: 16 Aug 2013
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PostPosted: 21:56 - 10 Sep 2015    Post subject: Reply with quote
The photos don't really do the barrels justice.

In reality they've been honed with a 35 degree angle.
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sickpup
Old Timer



Joined: 21 Apr 2004
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PostPosted: 07:17 - 11 Sep 2015    Post subject: Reply with quote
Nobby the Bastard wrote:
The photos don't really do the barrels justice.

In reality they've been honed with a 35 degree angle.


How was it done, by hand or honing machine?
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MarJay
But it's British!



Joined: 15 Sep 2003
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PostPosted: 07:43 - 11 Sep 2015    Post subject: Reply with quote
I was always taught that a hone should be done with a rotating honing tool once inwards and once outwards to achieve 45 degree hatching in both directions. Those honing marks look deep and horizontal...

Stan Stephens uses a tool which I think is called a ball hone or something. It looks like this:

https://www.ebay.co.uk/itm/1-5-8-41mm-FlexHone-Flex-Hone-320-grit-Silicone-Carbide-BC15832-/262030320923?_trksid=p2141725.m3641.l6368
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Nobby the Bastard
Harley Gaydar



Joined: 16 Aug 2013
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PostPosted: 14:46 - 11 Sep 2015    Post subject: Reply with quote
sickpup wrote:

How was it done, by hand or honing machine?


"Use honeing stones on a drill wet using engine oil. Try to get a decent 35 degree cross hone. Hard by hand but pretty close"


Not ideal, I know, but needs must.
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DJP
Crazy Courier



Joined: 11 Dec 2011
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PostPosted: 10:26 - 14 Sep 2015    Post subject: Reply with quote
Nobby the Bastard wrote:
The photos don't really do the barrels justice.

In reality they've been honed with a 35 degree angle.


They look fine to me.
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bladeblaster
Trackday Trickster



Joined: 19 Jan 2015
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PostPosted: 15:57 - 14 Sep 2015    Post subject: Reply with quote
Its not just Yamaha, Kawasaki also bury it deep in the bowels of the gearbox.

Or at least they did on the GPz900
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