Single Carb


Information and questions on GL1100 Goldwings (1980-1983)
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moneypit
Posts: 145
Joined: Mon Jul 07, 2014 2:43 pm
Location: Grand Haven Mi
Motorcycle: 1983 GL1100I Interstate

Single Carb

Postby moneypit » Sun Aug 03, 2014 10:17 am



Ok so syncing carbs on my 1100 is not my cup of tea. I understand wingers are converting to a single carb . Who out there is or has done such a thing anybody have any ideas is it a good thing bad thing let me know ....



tonyincny
Posts: 31
Joined: Sun Oct 10, 2010 9:10 pm
Location: Syracuse, New York
Motorcycle: 1982 GL1100I Interstate

Re: Single Carb

Postby tonyincny » Sun Aug 03, 2014 8:01 pm

I have the topic above you about putting air filter pods on a GL1100 and getting rid of the airbox. The topic has shifted a bit to your topic about a single carb. I've been reading a bunch of posts on the Internet about how it is a bad idea. The main problem is a loss of performance and top end speed. But, here's a reply I sent to one such post.

Of course there will be some degradation in performance by converting to a single carb. Just as an eight cylinder car will perform better with a carb for each cylinder as compared to a single carb. But, all cars (with carburetors) come from the factory with just a single carb, whether it is a 4, 6 or 8 cylinder vehicle, and that seems adequate for 99% of the buyers. Even a VW Beetle is two or three times heavier than a Goldwing and it manages just fine with a primitive single carburetor.
Does a Goldwing really require or does a Goldwing owner really require that level of performance that four carburetors give? The Goldwing is driven like a limousine not like a sports bike. Most Goldwing owners are fairly casual drivers just as they drive their passenger cars? Therefore, as they accelerate up to highway speeds then settle in at 65 mph or 70 mph, why do they need four carburetors? Does a mini-van require a carburetor for each cylinder?
Is all that extra and complex equipment necessary? Is maintaining the tuning and balancing of four carburetors really necessary when a single carburetor will give all the performance necessary for everyday driving?
A YouTube search of "GL1100 single carb" gives some videos and some insight into performing such a changeover.

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82aspen
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Location: canuck eh!
Motorcycle: 82 aspencade

Re: Single Carb

Postby 82aspen » Wed Aug 13, 2014 3:12 pm

a great alternative but mostly for folks who are handy with tools

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virgilmobile
Posts: 7663
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Single Carb

Postby virgilmobile » Thu Aug 14, 2014 7:21 am

I went away from the single carb idea for two reasons.
Performance.Single carb moves the atomized fuel 10" further from the intake valve compared to the individual carb.Over twice the distance.Throttle response suffered.

Deep curves tilt the single carb.fuel level changes.
Fine for the VW,it doesn't run at a 40*angle when in a deep curve like the bike.
The single carb is designed to stay level.

Do they work.?? Yes....would I expect greatness.??? No.Sorry.
I'll stick with OEM.

Or convert ( $$$$$ ) to multi port fuel injection...

tonyincny
Posts: 31
Joined: Sun Oct 10, 2010 9:10 pm
Location: Syracuse, New York
Motorcycle: 1982 GL1100I Interstate

Re: Single Carb

Postby tonyincny » Thu Aug 14, 2014 7:46 am

That's a good point, Single Carb, about how a single carb bike changes angles. I hadn't thought of how that would affect fuel delivery through the carb.
But, I can't help but think that there should be enough fuel in the bowl to compensate for that under "normal" highway or city driving.
If the bike is going to be ridden like a sport bike on a race-track then, yes, the constant shifting and severe leaning might show that a single carb isn't adequate.
Again, though, the Goldwing is the limousine of bikes and is pretty much ridden upright with minimal lean.
Here's a link I came across that discusses the difference between a Honda Spirit 750 with single and dual carbs - http://www.hondashadow.net/forum/72-tec ... mance.html
Here's a link for a Google search for "single carb motorcycles" that has many forum discussions on the issue - https://www.google.com/search?q=single+ ... 3&ie=UTF-8
KEEP IN MIND THAT ALL MY STATEMENTS ARE JUST MY OPINION. I have not done the conversion yet and have no idea of what the results might be. But, it is fun discussing the issue and sharing thoughts and ideas.

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RBGERSON
Posts: 2625
Joined: Tue Mar 09, 2010 7:57 am
Location: SCOTTSDALE, AZ
Motorcycle: 98 SE GL 1500
had every year from 75 to 83

Re: Single Carb

Postby RBGERSON » Thu Aug 14, 2014 8:33 am

Most who do it say they like it..and don't notice any difference in performance..there is but most would probably need to Dyna the bike to see it..one issue is freezing many add a water line to the intakes to warm them up. Look at Randall's site for lots of info..pic of intakes etc., carbs that work and general info..

lots of threads wit5h people arguing both sides of this idea.
HAD LOTS OF GOLDWING 75-83
NOW INTO 1500'S..RIDING A 1998 SE

FAIR WINDS,
RB

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HawkeyeGL1200
Posts: 918
Joined: Sat Jul 05, 2014 11:53 am
Location: Courtland, Va.
Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate

Re: Single Carb

Postby HawkeyeGL1200 » Thu Aug 14, 2014 11:58 am

I read all I could find on the subject a while back. I've never tried it. I like the idea, in principle, and won't debate the pro/con sides of the single carb, since I have no interest in arguing with anyone about anything. I'll just say this: Some love it, some hate it, some don't have an opinion... kind of like running a car tire on a motorcycle, I guess.... I think I could "do" a conversion if someone asked me to do it. If I ever get to where carb parts aren't available for my GL1200, and I am still riding it, I'd do the conversion or I'd buy a 1500...
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

tonyincny
Posts: 31
Joined: Sun Oct 10, 2010 9:10 pm
Location: Syracuse, New York
Motorcycle: 1982 GL1100I Interstate

Re: Single Carb

Postby tonyincny » Thu Aug 14, 2014 4:47 pm

Hi, Single Carb - I'm not sure what you meant by "or I'd buy a 1500." Oh, I think it just dawned on me. Did they switch to fuel injection then?

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HawkeyeGL1200
Posts: 918
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Location: Courtland, Va.
Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate

Re: Single Carb

Postby HawkeyeGL1200 » Thu Aug 14, 2014 5:35 pm

tonyincny wrote:Hi, Single Carb - I'm not sure what you meant by "or I'd buy a 1500." Oh, I think it just dawned on me. Did they switch to fuel injection then?

No fuel injected 1500's out and about... what I meant was, if I can no longer get parts for my 1200, I'd simply buy a newer version of a Goldwing, which I expect I could find parts for long after parts for the 1200's have become impossible to find.
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

tonyincny
Posts: 31
Joined: Sun Oct 10, 2010 9:10 pm
Location: Syracuse, New York
Motorcycle: 1982 GL1100I Interstate

Re: Single Carb

Postby tonyincny » Thu Aug 14, 2014 6:28 pm

You should be safe for now. I just did an eBay check and they have listed over 17,000 used parts for the GL1100. They even have over 14,000 used parts for my GL1100.

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82aspen
Posts: 122
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Location: canuck eh!
Motorcycle: 82 aspencade

Re: Single Carb

Postby 82aspen » Fri Aug 15, 2014 10:23 am

here's a recent report from i'd call a key player
http://www.goldwingfacts.com/forums/348 ... st564.html
This is Stovebolt Tom's Motorcraft 740/Weber 32DFT after 23k miles and more tuan 2 years of continuous use.
No alterations to the carb were made.
Installed directly out of the box and tuned only.
I've never tightened a single screw other than to mount what was necessary for the conversion.
Flawless performance.

Now, it will be cleaned and all fasteners checked for the first time.
...then reinstalled and reused.
Money well spent in my experience.

tonyincny
Posts: 31
Joined: Sun Oct 10, 2010 9:10 pm
Location: Syracuse, New York
Motorcycle: 1982 GL1100I Interstate

Re: Single Carb

Postby tonyincny » Fri Aug 15, 2014 11:05 am

Thanks for the info, SC.
To all you folks who may be viewing this discussion, note that the link that Single Carb just presented is page 57 of a long discussion about how this single carb conversion took place. This will be informative reading on some cold and rainy day when we can't get outdoors. It's bound to have a ton of vital information for anyone contemplating such a changeover on their Goldwing.
Thanks, again, SC.

P.S. - Wow, I just went back to the start of that thread and those guys really are knowledgeable about single carb conversions. I'm totally lost but maybe I can still get enough to start on my bike someday.

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HawkeyeGL1200
Posts: 918
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Location: Courtland, Va.
Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate

Re: Single Carb

Postby HawkeyeGL1200 » Fri Aug 15, 2014 11:23 am

The carb conversion in that thread appears to be the most simple and user friendly of all the ones I've read about... and I've read that entire thread and then some. Getting the runner diameter correct and applying heat to the runners and plenum seem to be the most crucial parts of the converions. Apparently that carb, out of the box, functions just the way it is.

There are a lot more experimental designs. I've seen photos and video of conversions where the builder used PVC, Aluminum, Copper and/or the original air-box and carbs (gutted the carbs and sealed all the shaft penetrations and used the airbox for a plenum to mount a carb on) and in every case, the builder managed to get the bike to run. Now, opinions vary on how well the bike(s) run after having the conversion done to them. I suppose a mediocre running motorcycle is better than one that won't start and run (to some folks) but if I had a bike that ran about half as well as it could, it would make me more angry than if it didn't run at all... so, I'd be very particular about making the change from 4 carbs to one if it meant sorry performance...
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

tonyincny
Posts: 31
Joined: Sun Oct 10, 2010 9:10 pm
Location: Syracuse, New York
Motorcycle: 1982 GL1100I Interstate

Re: Single Carb

Postby tonyincny » Fri Aug 15, 2014 11:37 am

I see on eBay that there are several different manifold designs for sale. I have a LOT more research to do before I think about tearing apart my stock, working bike.
This conversion idea is just a dream that seems to be a simpler mechanical setup that would be easier to maintain. If I find out that the cost and other factors make it prohibitive then I'll just buy a mercury carb balancing set and tune the carbs I've got.
But, it's nice to dream when retired. It keeps my mind active.

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82aspen
Posts: 122
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Location: canuck eh!
Motorcycle: 82 aspencade

Re: Single Carb

Postby 82aspen » Fri Aug 15, 2014 11:46 am

HawkeyeGL1200 wrote: Now, opinions vary on how well the bike(s) run after having the conversion done to them. I suppose a mediocre running motorcycle is better than one that won't start and run (to some folks) but if I had a bike that ran about half as well as it could, it would make me more angry than if it didn't run at all... so, I'd be very particular about making the change from 4 carbs to one if it meant sorry performance...

that's prob a majority however there are many now and lotsa info out there, from folks who are thrilled with going and using scc

there have been great inroads made over the last few years that as far as i'm concerned are gamechangers, a main one is having identified and esablished a cheap, solid, new and baseline carb sometimes referred to as stovebolt

the info is now out there but is still a major pia to easily find

f1xrupr
Posts: 396
Joined: Mon Jan 13, 2014 6:13 am
Location: Triplet Va
Motorcycle: 1980 gl 1100 Std. Vetter

Re: Single Carb

Postby f1xrupr » Mon Aug 18, 2014 11:25 am

Cool topic ...if I had carb problems, and could find the conversion cheap (or less), I would try it. I wouldn't disturb a good running bike though...just saying... :roll:


My exercise bike is a goldwing.


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