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Differences in GL1100 Carb Models

Posted: Sat Jan 09, 2021 2:17 pm
by MattMcCoy
I have two racks of carbs (48A & 48C). It’s been my understanding that the 80/81 carburetors have pressed-in idle jets, while the 82/83 have screw-in idle jets. However, at a quick glance, it appears that the 48A and 48C carbs on my bench both have screw-in jets. Also, from what I gather here and elsewhere, all original 1100 carbs were all jetted the same, including the one-off ‘83 Aspencade. Do I have this right? What about 48B — were there any differences?

Thanks.

Re: Differences in GL1100 Carb Models

Posted: Sun Jan 10, 2021 5:00 pm
by MattMcCoy
Here’s some pics of the 48A carbs, if anyone is interested.
GL1100 48A Carburetors
GL1100 48A Carburetors
8643B332-C087-4B8E-B366-7D3CABE94ECC.jpeg (224.04 KiB) Viewed 586 times
48A Jets
48A Jets
235C5294-06B0-40BF-AEB3-90552E1488C1.jpeg (263.34 KiB) Viewed 586 times
48A Idle Jet
48A Idle Jet
AAF54E60-8F20-4958-AD51-EB99FE1CCEC1.jpeg (272.13 KiB) Viewed 586 times

Re: Differences in GL1100 Carb Models

Posted: Mon Jan 11, 2021 11:31 am
by Whiskerfish
Unfortunately I am not a 1100 carb guy. I think I have one rack in the garage somewhere that came on a bike but otherwise I have never worked on one. Hopefully someone will chime in with some answers to you inquiries.

Re: Differences in GL1100 Carb Models

Posted: Mon Jan 11, 2021 2:30 pm
by MattMcCoy
Thanks for the reply. I get the impression that the Internet has come to an understanding on the 1000 carbs and would imagine that’s the same case with with the 1100 sets too. I’ve rebuilt a 48C and have two more sets (48A/48C) and can’t spot any differences. From reading, the 80/81 has pressed-in jets, but don’t know how those are designated on the carb bodies. I reckon there’s a 48B as well?

Thanks again.

Re: Differences in GL1100 Carb Models

Posted: Mon Jan 11, 2021 8:50 pm
by Track T 2411
16104118058275616076875846385774.jpg
16104118058275616076875846385774.jpg (151.74 KiB) Viewed 536 times
This is a jet from a 48C carb that was on my '81. The middle shiny ring is where it seats in the carb body. I can't really tell much difference between the bore of the 48C and the 48A, and I couldn't find the screw- in jet from the 48A in my carb parts stash right off hand to do a side- by- side comparison. Maybe I'll dig some more tomorrow...

Re: Differences in GL1100 Carb Models

Posted: Mon Jan 11, 2021 9:12 pm
by MattMcCoy
Strange. I have 48C on my ‘83 Aspencade and it has screw-in jets.

Re: Differences in GL1100 Carb Models

Posted: Wed Jan 13, 2021 3:23 pm
by Track T 2411
MattMcCoy wrote: Mon Jan 11, 2021 9:12 pm Strange. I have 48C on my ‘83 Aspencade and it has screw-in jets.
Are you sure you're not mixing up the letters? 48C is '80-81, 48A is '82-83, IIRC...
FWIW, the 48C carb body does 'look' like one could tap the tower to accept a threaded jet, but that's just a quick eyeball measurement, lol. It does make me curious...

Re: Differences in GL1100 Carb Models

Posted: Wed Jan 13, 2021 10:01 pm
by MattMcCoy
The first photo is the set on my ‘83 Aspencade, which has a threaded idle jet. I believe they are the original set and had never been opened before I rebuilt them. The red arrow points to the letter A, but you might be able to make out that 48C is stamped on the body as well.
‘83 GL1100A carbs
‘83 GL1100A carbs
D0E012FE-C3B9-4DF9-928C-77FBF0641EC1.jpeg (54.15 KiB) Viewed 505 times
In the second photo, I’ve marked where I might be getting confused. Again, the red arrow points to the stamped A, but the yellow one points to 48A. The idle jet is threaded on this set as well.
Unknown year GL1100 carbs
Unknown year GL1100 carbs
C0A3519E-2D1C-4774-A66A-AD383F3D447C.jpeg (186.02 KiB) Viewed 505 times
All three sets I have are stamped with A, but two begin with 48C and one begins with 48A. Does that make sense?

Re: Differences in GL1100 Carb Models

Posted: Thu Jan 14, 2021 3:02 am
by MattMcCoy
The ‘80/‘81 Gl1100 carbs are stamped with VB48A [A]. The letter in the bracket indicates what factory they came out of, which would be Ohio in this case.
80/81 GL1100 carbs VB48A [A]
80/81 GL1100 carbs VB48A [A]
2BE41463-440C-404C-A94A-A0A84003C81C.jpeg (215.11 KiB) Viewed 493 times
The ‘83 GL1100 carbs will be stamped with VB48C [A].
‘83 GL1100 carbs VB48C [A]
‘83 GL1100 carbs VB48C [A]
C645C9B5-500C-4C3D-807B-5B503750C6AD.jpeg (114.93 KiB) Viewed 493 times
While it would appear that the 48A set came from an 80/81, it doesn’t explain why it has a screw-in idle jet.

Re: Differences in GL1100 Carb Models

Posted: Fri Jan 15, 2021 10:32 am
by redglbx
80-81 carbs are the 48 A’s,,, 82-83 use the 48 C’s ,,, the A’s have press-in jets, the C’s use screw in jets. Easy-peasy !

I personally would not mix carbs because there are usually things different that may not be obvious, like the 48c’s that I have on my 76 have coated slides (black, probably moly) that are supposed to help keep them from sticking, but I have another set of 48c’s that the slides are not coated. I would never mix & match different number carbs, it’s just a bad idea.

Re: Differences in GL1100 Carb Models

Posted: Fri Jan 15, 2021 10:58 am
by MattMcCoy
redglbx wrote: Fri Jan 15, 2021 10:32 am 80-81 carbs are the 48 A’s,,, 82-83 use the 48 C’s ,,, the A’s have press-in jets, the C’s use screw in jets. Easy-peasy !

I personally would not mix carbs because there are usually things different that may not be obvious, like the 48c’s that I have on my 76 have coated slides (black, probably moly) that are supposed to help keep them from sticking, but I have another set of 48c’s that the slides are not coated. I would never mix & match different number carbs, it’s just a bad idea.
Thanks for the reply. I think I have it sorted out. The mystery is why the 48A carbs on my bench have screw-in jets instead of pressed. I suppose someone could have tapped it and replaced the jet, but they didn’t appear to have ever been opened.

Re: Differences in GL1100 Carb Models

Posted: Sat Jan 16, 2021 11:13 am
by Old Fogey
I've had 48As with screw in jets too, although most are pressed in. Oddly, in all the 1100 carbs I've done I've not had a set of 48C in. So, no-one is mentioning the 49A with pressed in jets, two sets of which I have but don't know which model they come off.

Re: Differences in GL1100 Carb Models

Posted: Sun Jan 17, 2021 11:51 am
by MattMcCoy
Old Fogey wrote: Sat Jan 16, 2021 11:13 am I've had 48As with screw in jets too, although most are pressed in. Oddly, in all the 1100 carbs I've done I've not had a set of 48C in. So, no-one is mentioning the 49A with pressed in jets, two sets of which I have but don't know which model they come off.
Interesting — thanks for the info.