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Bumps on Cam Bearings
- JakeB
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Some of my cam bearing inserts have little raised bumps on them. Is this a problem?
1978 Z1-R
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- testarossa
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It's my build thread, and I must say that my bearings look exactly like yours. So far, the consensus on here was to re-use them as-is. However, my bumps are raised just like yours. Personally, I'm not comfortable re-using them, so I'll either replace them with an ebay set or buy new. They sure are proud of those little guys. IIRC they are about $7 a peice.
BTW I have the same problem with the search feature, but fortunatly the search nazis aren't too bad here.
1978 KZ1000 A2 Click--->Build Thread
2004 ZX-10R
2007 Harley Sportster 1200
2020 Harley Street Glide Special
Angola, IN
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- JakeB
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You said yours were all on the top halves, but mine are mostly on the bottoms. The worst one (pictured above) is one of the intake bottom halves on the left of the motor.
I'm still deciding whether to replace them or not, Z1E has them for $7.50 each or if you buy a set of 16 - $6.50 each, that's still $104 for new ones.
If I do reuse them should I try to sand off the bumps or just put them back in the way they were?
1978 Z1-R
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- TeK9iNe
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When in doubt, THROW IT OUT! :laugh:
These bikes are supposed to cost a lotta $$$... :laugh:
GL
Motorcycle Shop Owner/Operator
79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors
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- testarossa
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Here's one question that still bothers me. Does this engine not rely on those bearings having good fit to maintain oil pressure? Mine are significantly out of round, and I'm used to bearing clearances being measured in the neighborhood of 0.0002" That's not happening on these bearings. I think my bumps were at least 0.005" tall.
Edit: I agree with what tek9ine says. I'm still replacing mine.
1978 KZ1000 A2 Click--->Build Thread
2004 ZX-10R
2007 Harley Sportster 1200
2020 Harley Street Glide Special
Angola, IN
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- T_Dub
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1977 KZ650B1
-810cc
-Cavanaugh Racing Head
-Mikuni RS34's
-GPR Muffler
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- BSKZ650
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small price to pay for new ones now rather than mess up the rest of the motor later
77 kz650, owned for over 25 years
77 ltd1000, current rider
76 kz900, just waiting
73 z1,, gonna restore this one
piglet, leggero harley davidson
SR, Ride captian, S.E.Texas Patriot Guard Riders.. AKA KawaBob
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- testarossa
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1978 KZ1000 A2 Click--->Build Thread
2004 ZX-10R
2007 Harley Sportster 1200
2020 Harley Street Glide Special
Angola, IN
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- JakeB
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There will be a brand new set in my next order from Z1E.
This might be an important thing to check on any bike that has been sitting for awhile.
1978 Z1-R
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- Jeff.Saunders
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When engines run, they gradually contaminate the oil with acid, water and left over chemicals from gasoline that makes it's way past the rings. I would suspect the engine sat with very old oil in it for all those years.
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- testarossa
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I've never seen any looking like that. It would seem likely to be some form of contamination in the oil that corroded the metal.
When engines run, they gradually contaminate the oil with acid, water and left over chemicals from gasoline that makes it's way past the rings. I would suspect the engine sat with very old oil in it for all those years.
Mine sat for about 15 years with dirty oil in it. Unknown miles, but I'm guessing not too many since the cam lobes were still in spec. It would be interesting to see if any other bikes that have been stored for extended periods have this issue. I have never seen bearings look like this in any engine that I have dissasembled of any type. It makes two KZ motors with this.:huh:
1978 KZ1000 A2 Click--->Build Thread
2004 ZX-10R
2007 Harley Sportster 1200
2020 Harley Street Glide Special
Angola, IN
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