Author Topic: whats the difference in heads?  (Read 914 times)

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Offline Doggie

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whats the difference in heads?
« on: January 24, 2015, 04:38:27 PM »
Does anyone know what the difference is between a 1980 CB650 head and a 1981 CB650 head?
 Can they be swapped out?
                                           Thanks, Doug

Offline MiGhost

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Re: whats the difference in heads?
« Reply #1 on: January 24, 2015, 07:28:08 PM »
In 81 the intake port spacing in the cylinder head was changed to a match the CV carbs. The 80 cylinder head will bolt in place of the 81 head, but the 80 head will need the mechanical carbs to match the intake spacing.
~ Ghost

Grey Ghost '80 CB650C: Updated Stock Restomod. Period Custom Cruiser (OEM harbags & trunk, Wixom Ranger fairing, Jardine turnouts)
Bad Moon '83 XJ750MK Midnight Maxim: Full Dress Tour Deluxe w/ X-1 Fairing

Offline Doggie

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Re: whats the difference in heads?
« Reply #2 on: January 24, 2015, 08:39:31 PM »
Great...Thats what I needed to know.      Thanks, Doug

Offline 754

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Re: whats the difference in heads?
« Reply #3 on: January 24, 2015, 09:28:55 PM »
I have a brand new 650 head if anyone needs one. Have to check the spacing.
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Offline MiGhost

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Re: whats the difference in heads?
« Reply #4 on: January 25, 2015, 09:41:52 PM »
I have a brand new 650 head if anyone needs one. Have to check the spacing.
Frank, You can tell the difference between the early, and late 650 heads by the bottom 2 fins on the intake side. The early 79-80 mechanical carb head has the fins straight across the entire length. The late 81-82 CV carb head has the fins cut back under the intake ports.
~ Ghost

Grey Ghost '80 CB650C: Updated Stock Restomod. Period Custom Cruiser (OEM harbags & trunk, Wixom Ranger fairing, Jardine turnouts)
Bad Moon '83 XJ750MK Midnight Maxim: Full Dress Tour Deluxe w/ X-1 Fairing

Offline Doggie

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Re: whats the difference in heads?
« Reply #5 on: January 26, 2015, 12:52:35 PM »
Thanks again for the help.   You guys are sharp!!     Doug