Cam wear

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07 May 2023 12:58 #884363 by timewaster
Cam wear was created by timewaster
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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07 May 2023 15:08 #884367 by hardrockminer
Replied by hardrockminer on topic Cam wear
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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07 May 2023 16:21 #884368 by JR
Replied by JR on topic Cam wear
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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07 May 2023 16:45 #884369 by Wookie58
Replied by Wookie58 on topic Cam wear

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.)

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07 May 2023 20:16 #884375 by timewaster
Replied by timewaster on topic Cam wear
I replaced them, thanks for the reply.

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07 May 2023 20:17 #884376 by timewaster
Replied by timewaster on topic Cam wear
Thanks for your reply. I'll try and find the factory spec.

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08 May 2023 04:34 #884397 by TexasKZ
Replied by TexasKZ on topic Cam wear
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
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09 May 2023 17:47 #884458 by timewaster
Replied by timewaster on topic Cam wear
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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09 May 2023 17:59 #884459 by Nessism
Replied by Nessism on topic Cam wear
What measurements did you get, and did you use a micrometer to measure?

 

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10 May 2023 07:00 #884473 by blipco
Replied by blipco on topic Cam wear
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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10 May 2023 09:46 #884481 by timewaster
Replied by timewaster on topic Cam wear
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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10 May 2023 10:15 #884482 by timewaster
Replied by timewaster on topic Cam wear
Blipco asked if I had pics of the cams.
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