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Discussion Starter #1
Can anyone tell me if the camshaft in my 78 super sport is the same as all 750's? If not, what is the difference.

Thanks, Roy
 

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Short answer: no

Long answer:
They are different. For starters the 78 cb750F head uses bigger valves (34/31mm i/o 32/28mm) than all previous cb750 engines.

As I understand it the K0 to K6 (1969-1976) cams are all pretty much the same. The 1975-76 F bikes got a revised camshaft that was then used on the 1977-78K bikes as well.

The 1977-78 F bikes got their own camshaft, I know it has more lift and more duration but I'll be damned if I know what the exact numbers are.



Edited by - geeto67 on Dec 10 2007 4:55:32 PM
 

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Discussion Starter #3
Thanks Geeto. I am in the process of installing K cylinders, pistons and head on my '78 Super Sport and I needed to know whether the cam had to swap also. Any other pointers you guys can give me on this procedure would be greatly appreciated.
 

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whenever someone has the motor apart on these I say put in a big bore kit. It is such a pain in the arse to take the out of the frame and tear them down, and you won't have to do it again for atleast another 50K miles (unless a gasket goes).

Take a straight edge and make sure the cylinder head and cylinder block are not warped. This is usually the first gasket to go. Also pay really close attention to the o-rings that go in the cylinder block (if you are using a 73 and later K block that has these), as they often pop too and are crutial to having a leak free honda engine (as well as top end oiling).

If you are going to do an upgrade, I hear a 75-76 supersport cam isn't a bad cam to run, espically with your 1978 carbs with the accelerator pump.
 

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Discussion Starter #5
As I have to find new pistons anyway, I might as well go the big bore route. Where is a good place to find the kits for not a crazy bunch of money?
 

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Discussion Starter #6
As I have to find new pistons anyway, I might as well go the big bore route. Where is a good place to find the kits for not a crazy bunch of money?
 

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www.dynoman.net. He even has kits for the F2 motors, but you want a K motor one so you can use your K head. Thes are forged wiseco pistons and cost about $429

Even cheaper is Ken at cycle exchange's cast 850cc kits. At $249 they are not bad. They are cast pistons so they would be for a mild street motor.

personally I try to spend the money for forged when I can but a cast piston is not so bad if you don't go too radical on the motor.
 

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www.dynoman.net. He even has kits for the F2 motors, but you want a K motor one so you can use your K head. Thes are forged wiseco pistons and cost about $429

Even cheaper is Ken at cycle exchange's cast 850cc kits. At $249 they are not bad. They are cast pistons so they would be for a mild street motor.

personally I try to spend the money for forged when I can but a cast piston is not so bad if you don't go too radical on the motor.
 
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