z750L: Repair starter clutch

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Re: z750L: Repair starter clutch

27 Jun 2025 10:13
#914145
Yes was them I was thinking about, did feel/hear any difference after replacing them?
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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Re: z750L: Repair starter clutch

02 Jul 2025 06:57
#914319
Starter gear, quite big difference compare new and old:

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
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Re: z750L: Repair starter clutch

04 Jul 2025 04:11
#914358
Secondary shaft nut         - 60 Nm (44 ft.lbs)
Clutch hub nut            - 108-160 Nm (80-118 ft.lbs)
Clutch Spring Bolt`s         - ??? 
Oil Pan screws            - 6-9 Nm (5-7 ft.lbs)

Somebody know how many Nm I should apply on the Clutch Spring Bolt`s  ?
Is their some bolts/nuts I have forgotten?

I can apply the same Nm on nut for secondary shaft on both side of the motor?

Hope I can the last package during tody so I can complete these during the weekend...
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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Re: z750L: Repair starter clutch

04 Jul 2025 10:25
#914370
Driller off the head on the nails today, should I just keep the rest of the nail and then weld between the rest and the plate?

Use something to push the plate completly down before welding, their are 3 springs pushing against?

the red frition plate is broken, I don’t need a new one?

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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Re: z750L: Repair starter clutch

04 Jul 2025 10:50
#914371
You drilled off more of the rivet than might be ideal.  The rivets on my hub were flush after clamping everything down for the welder.

The red gasket thing isn't needed, from what I've read from others doing this repair.

[img
P1020572 by nessism , on Flickr
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Re: z750L: Repair starter clutch

04 Jul 2025 11:07 - 04 Jul 2025 11:21
#914372
Ah, okay. Did you grind the surface of the plate where you’re going to weld? Is it to ensure a better weld?

The welder ask if it’s normal black steel?
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Last edit: 04 Jul 2025 11:21 by gordone.
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Re: z750L: Repair starter clutch

04 Jul 2025 11:25
#914373
You drilled off more of the rivet than might be ideal.  The rivets on my hub were flush after clamping everything down for the welder.

The red gasket thing isn't needed, from what I've read from others doing this repair.

P1020572 by nessism , on Flickr
This is why I suggested "grind" not "drill" but if your welder is on his "A" game you should be OK

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Re: z750L: Repair starter clutch

04 Jul 2025 11:35 - 04 Jul 2025 11:41
#914374
Did not read good enougf :(

I talked with welder and see he has alot to weld on, he is pro so hope he is correct :)
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Last edit: 04 Jul 2025 11:41 by gordone.
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Re: z750L: Repair starter clutch

08 Jul 2025 14:09
#914454
I got the starter clutch installed today, but have some questions.

1. How can I torque up the clutch hub nut without the special clutch tool? I have a power gun that torque up to 400nm… how import is the nm on these nut?

2. The old paper gasket on the oilpane and clutch cover, I need to get it away 100% to avoid oil leak with the new gasket? Razerblad is the best to use for removing?
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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Re: z750L: Repair starter clutch

08 Jul 2025 16:19
#914455
You can try putting it in 1st gear and get someone to apply the rear brake while you torque the nut. Correct torque is important 
A razor blade will work but be careful not to damage the surface 

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Re: z750L: Repair starter clutch

08 Jul 2025 19:35
#914461
Scotchbrite pad (maroon or gray, green is not coarse enough) with carb cleaner will get you clean gasket surfaces
Scotty

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Re: z750L: Repair starter clutch

08 Jul 2025 22:14 - 08 Jul 2025 22:15
#914464
You can try putting it in 1st gear and get someone to apply the rear brake while you torque the nut. Correct torque is important 
A razor blade will work but be careful not to damage the surface 
I saw the same tips in the service guide made by a user on the forum, but when it's set in 1st gear, it will spin, since I don’t have any friction plate or springs installed… No clutch is installed, right?

I feel that is something stupid I don`t understand here :)
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Last edit: 08 Jul 2025 22:15 by gordone.

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