milling gl1ooo cylinder heads

Information and questions on GL1000 Goldwings (1975-1979)
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Posts: 66
Joined: Tue Jun 28, 2011 9:07 pm
Location: Willoughby,OH
Motorcycle: 1976 GL1000
1972 CB750K2
1977 CB750f

milling gl1ooo cylinder heads

Post by ntintruder »

Cleaning up a pair of gl1000 cylinder heads I found some erosion around the coolant ports on one of the heads. About i/4 inch wide by 3/8 inch long, slightly pitted marks going down and away from each port. Could the cylinder head gasket around the ports been seeping coolant and would this cause the pitting on the surface of the head? The other head has no marks at all. I am thinking of milling the gasket surface on each head to get rid of the pitting so is there a maximum amount you can safely remove? Obviously you can't get into the combustion chamber and the compression will go up. Does this cause any problems?

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Re: milling gl1ooo cylinder heads

Post by rzaugg »

Can you post some pictures? Am curious where on the head the pitting is. There is a lot of surface area on the heads, that doesn't mate up to anything on the block and is primarily there for structure and for control of coolant flow. Pitting in that area I wouldn't see as even being a problem.

As far as milling, you could theoretically go to just short of the edge of the valves and it really wouldn't change things a whole lot. If you had to take a lot off, the coolant tubes that bolt to the top side of the heads might be a bit long. That's the only thing that I can think of while sitting here that may cause a problem
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