Author Topic: Question: Time for a new Valve Train?  (Read 970 times)

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Offline NewOldSchool

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Question: Time for a new Valve Train?
« on: March 10, 2014, 09:48:03 PM »
Hey guys quick question:

I did a mild rebuild on my 1974 CB750 K4 at 30k. Pistons, rings, valve guides, valves and seats cut, new cam chain tensioner, head and block surfaced, etc. I now have almost 50k on it and the rocker arms and shafts have now worn to the point that the top end is making a fairly loud clacking sound. I'm going to pull the motor to investigate further.

There are several valve train sets on eBay from lower mileage bikes. Besides the rocker shafts not being locked down on earlier year bikes are there any other differences or can I buy a good valvetrain from say a '72 and drop the A and B blocks right in?

Thanks!
Not putting miles on your bike is like not having sex with your Girl Friend so she'll be more desirable to her next Boy Friend.

Offline NewOldSchool

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Re: Question: Time for a new Valve Train?
« Reply #1 on: March 11, 2014, 10:42:17 AM »
Bump, I guess Ill try another section.
Not putting miles on your bike is like not having sex with your Girl Friend so she'll be more desirable to her next Boy Friend.

Offline SOHC4 Cafe Racer Fan

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Re: Question: Time for a new Valve Train?
« Reply #2 on: March 11, 2014, 01:42:47 PM »
NOS,

The components should be interchangeable.  You may want to have a machinist resurface the mating surfaces of the cylinders and head to eliminate any warped surfaces to ensure a good seal.
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