Cam wear

  • timewaster
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Cam wear

07 May 2023 12:58
#884363
I am trying to put an 82 KZ 1000 back on the road. It was spitting back through no. 1 carb, so I was thinking valves might need some attention. I pulled the valve cover, and by the book started to torque the cam bearings down. All but two were stripped, so I pulled the head and sent it out for heli coils. Since the cams were laying to the side, I thought I may as well measure them for wear. The Clymer manual I have has a table of acceptable cam wear in it. All were worn past acceptable limits, the least being .014, and the most being .034 under the spec. 

I had someone tell me to shim them back in spec. Is this realistic? Somehow, doesn't seem right. This IS my first rodeo.
Any information is appreciated

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  • hardrockminer
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Re: Cam wear

07 May 2023 15:08
#884367
I suspect they misunderstood, thinking the valve clearance needed shimming.  As for the cams, I haven't seen excess wear very often, but if I did I'd look at replacing them.
I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
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  • JR
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Re: Cam wear

07 May 2023 16:21
#884368
With my 750 spitting back through the carbs at low speed/idle was a signal that the carb to engine rubbers were cracked and needed replacing. 

sorry cant offer any input on the cams.
1980 kz750E1, Delkevic exhaust

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  • Wookie58
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Re: Cam wear

07 May 2023 16:45
#884369
timewaster wrote:
I am trying to put an 82 KZ 1000 back on the road. It was spitting back through no. 1 carb, so I was thinking valves might need some attention. I pulled the valve cover, and by the book started to torque the cam bearings down. All but two were stripped, so I pulled the head and sent it out for heli coils. Since the cams were laying to the side, I thought I may as well measure them for wear. The Clymer manual I have has a table of acceptable cam wear in it. All were worn past acceptable limits, the least being .014, and the most being .034 under the spec. 

I had someone tell me to shim them back in spec. Is this realistic? Somehow, doesn't seem right. This IS my first rodeo.
Any information is appreciated
Firstly I would suggest that you don't take any further advice from the person who said "shim them back into spec" !!! Valve clearances are measured against the back of the cam lobe which doesn't come into contact with anything so can't "wear". I would also suggest checking the specs in the "Factory" service manual. Are the tips of the lobes shiney ? If they are worn excessively I would expect them to be dull or blued. Unless the bike has done spaceship mileage if the cams are worn this will likely be a result of poor maintenance, wrong oil or a oil pressure/flow issue to the head (if it is a lubrication problem I would also expect the cam bearings to show signs of wear/ heat.)
1982 KZ1000 Ltd
www.kzrider.com/forum/11-projects/617631...-82-begins?start=192
kzrider.com/filebase-alias?view=download...d-fault-diagnosis&ca

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Re: Cam wear

07 May 2023 20:16
#884375
I replaced them, thanks for the reply.

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  • timewaster
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Re: Cam wear

07 May 2023 20:17
#884376
Thanks for your reply. I'll try and find the factory spec.

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  • TexasKZ
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Re: Cam wear

08 May 2023 04:34
#884397
Here is a pdf copy of the factory service manual.     www.kzrider.com/modules/ServiceManuals/K...Service%20Manual.pdf
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
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Re: Cam wear

09 May 2023 17:47
#884458
I found the owners manual, and the Kawasaki wear spec and the Clymer wear spec differed by .001. I need new cams. Got any ideas on that? Only ones I can find are on Ebay, or aftermarket performance pieces for several hundred dollars. Kind of gun shy about buying used off Ebay, as they may be worse than mine. I contacted a couple of sellers to ask if they would measure them, but got no reply.

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  • Nessism
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Re: Cam wear

09 May 2023 17:59
#884459
What measurements did you get, and did you use a micrometer to measure?

 
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0

www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know

1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread

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  • blipco
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Re: Cam wear

10 May 2023 07:00
#884473
Do you have pictures of the old cams? 
"Swim against the current, even a dead fish can go with the flow"-somebody (I forget Who)

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Re: Cam wear

10 May 2023 09:46
#884481
I don't have a mic. that large, but I have calipers. The minimum for intake was 1.449" (36.804 mm.). I measured 1.415" ( 35.941 mm) to 1.425" (36.195mm.) on the intake. 
I measured 1.430"(36.322mm.) to 1.428" (36.271 mm.) on the exhaust. The manual says 1.443" (36.652mm.)
The exhaust isn't as bad as the intake, but still below the stated minimum.

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Re: Cam wear

10 May 2023 10:15
#884482
Blipco asked if I had pics of the cams.

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