Author Topic: barrel spigot diameter  (Read 599 times)

Offline masonmart

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barrel spigot diameter
« on: May 26, 2016, 01:27:07 PM »
The CB500 that I'm working on has a big bore kit fitted. Have just put the gasket in place, set on the barrels and then put on the cylinder head. Horror! the gasket between the crank case and barrels had split and the ends were sticking out. My guess is that the gasket was a CB500 (I bought the gasket based on the bottom end) and the barrels are of a 550 because you can't otherwise bore them out for the big bore kit.

Could there be any other reasons for this to happen?
Dresda CB500-4, 605 cc
CB-77, 350 cc
1968 Bonneville
1976 Thruxton Velocette
1974 Kawasaki Avenger
1997 VFR 750

Offline hairygit

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Re: barrel spigot diameter
« Reply #1 on: May 26, 2016, 02:10:35 PM »
Crap aftermarket gaskets? The most likely reason is the crankcase mouths have been machined out to suit the 550 barrels, chances are with a 550 base gasket all will be well.

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If it's got tits or wheels, it's hassle, if it's got both, RUN!!!

Offline masonmart

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Re: barrel spigot diameter
« Reply #2 on: May 26, 2016, 02:47:30 PM »
Crap aftermarket gaskets? The most likely reason is the crankcase mouths have been machined out to suit the 550 barrels, chances are with a 550 base gasket all will be well.

Sent from my X6pro using Tapatalk

Just looking at the gasket and it really is poor quality. Ordered a new gasket but it's annoying being held up.
Dresda CB500-4, 605 cc
CB-77, 350 cc
1968 Bonneville
1976 Thruxton Velocette
1974 Kawasaki Avenger
1997 VFR 750

 

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