GL1000 Heads Differences


Information and questions on GL1000 Goldwings (1975-1979)
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wingingit1
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Motorcycle: 1975 GL1000 Barn Find

GL1000 Heads Differences

Post by wingingit1 » Wed Feb 07, 2018 8:59 am



Hi,

Now that I've got a few GL's in the garage and have started digging into them, I am finding differences between the three '75 45,000 mile machines. Between different handlebars, exhausts and random electrical wiring PO's put on them, I have slightly different heads on one.

I have 3 sets of heads with the Blue press-in Honda logo on the valve covers and one with a black, screw in Honda logo. From what I can tell the Blue logo is for early GL1000s? The black came after?

Also it seems like the 75-76 heads had hotter cams than later 1000s. Otherwise are they dimensionally interchangeable?

Is there any way to tell what is going on by the casting numbers on the heads? Perhaps they're the same and I'm making things up.







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Fred Camper
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Location: Metro Detroit, MI
Motorcycle: 1977 GL1000, 1976 LTD GL1000

Re: GL1000 Heads Differences

Post by Fred Camper » Wed Feb 07, 2018 10:53 pm

You are correct on the cam cov rate and hotter cams. Better carbs on the early years also as the GL1000 began as a sports bike and later a touring bike. I know little of the difference if any for the heads.

Shadowjack
Posts: 37
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Location: Bellevue, NE
Motorcycle: 1977 GL1000
1975 CB750
2011 NT700VA

Re: GL1000 Heads Differences

Post by Shadowjack » Thu Feb 08, 2018 9:05 am

Partzilla shows all 1000s with the same part number, for both left and right...

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ekvh
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Re: GL1000 Heads Differences

Post by ekvh » Thu Feb 08, 2018 12:12 pm

75-77 had the more aggressive cams. Some 75 cams had a shorter stub for the tach drive and fuel pump. I think 77 had black cover plates , but not positive.

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jeffcosmo
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1983 GL1100 Aspencade
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Re: GL1000 Heads Differences

Post by jeffcosmo » Thu Feb 08, 2018 12:17 pm

Shadowjack wrote:
Thu Feb 08, 2018 9:05 am
Partzilla shows all 1000s with the same part number, for both left and right...
This would be for inventory purposes, as they interchange perfectly, though performance would be a bit different. Honda may have even consolidated P/N's for that reason as well.

Cosmo

Shadowjack
Posts: 37
Joined: Wed Aug 17, 2011 5:22 pm
Location: Bellevue, NE
Motorcycle: 1977 GL1000
1975 CB750
2011 NT700VA

Re: GL1000 Heads Differences

Post by Shadowjack » Thu Feb 08, 2018 6:24 pm

jeffcosmo wrote:
Thu Feb 08, 2018 12:17 pm
Shadowjack wrote:
Thu Feb 08, 2018 9:05 am
Partzilla shows all 1000s with the same part number, for both left and right...
This would be for inventory purposes, as they interchange perfectly, though performance would be a bit different. Honda may have even consolidated P/N's for that reason as well.

Cosmo
Heh. I have a hard-copy GL1000 parts manual dated January 1977, for bikes through 1977, and it's the same number as online now -- 12200-371-010. Everything later would be the same if the numbers were kept. Just the head and cam carrier assembly, mind you, nothing else. Change the cams and carbs to get whatever performance differences there were. Ports would be the same.

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Fred Camper
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Location: Metro Detroit, MI
Motorcycle: 1977 GL1000, 1976 LTD GL1000

Re: GL1000 Heads Differences

Post by Fred Camper » Fri Feb 09, 2018 6:32 pm

Makes sense to me since the exhaust gaskets are the same for all 4 cylinder years.



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