Single Carb
- moneypit
- Posts: 145
- Joined: Mon Jul 07, 2014 2:43 pm
- Location: Grand Haven Mi
- Motorcycle: 1983 GL1100I Interstate
Single Carb
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 ....
-
- Posts: 31
- Joined: Sun Oct 10, 2010 9:10 pm
- Location: Syracuse, New York
- Motorcycle: 1982 GL1100I Interstate
Re: Single Carb
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.
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.
Re: Single Carb
a great alternative but mostly for folks who are handy with tools
- virgilmobile
- Posts: 9087
- 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
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 ( $$$$$ ) to multi port fuel injection...
Performance.Single carb moves the atomized fuel 10" further from the intake valve compared to the individual carb.Over twice the distance.Throttle response suffered.
Deep curves tilt the single carb.fuel level changes.
Fine for the VW,it doesn't run at a 40*angle when in a deep curve like the bike.
The single carb is designed to stay level.
Do they work.?? Yes....would I expect greatness.??? No.Sorry.
I'll stick with OEM.
Or convert ( $$$$$ ) to multi port fuel injection...
-
- Posts: 31
- Joined: Sun Oct 10, 2010 9:10 pm
- Location: Syracuse, New York
- Motorcycle: 1982 GL1100I Interstate
Re: Single Carb
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.
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.
- RBGERSON
- Posts: 3233
- 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
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.
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
NOW INTO 1500'S..RIDING A 1998 SE
FAIR WINDS,
RB
- HawkeyeGL1200
- Posts: 918
- Joined: Sat Jul 05, 2014 11:53 am
- Location: Courtland, Va.
- Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate
Re: Single Carb
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.
-
- Posts: 31
- Joined: Sun Oct 10, 2010 9:10 pm
- Location: Syracuse, New York
- Motorcycle: 1982 GL1100I Interstate
Re: Single Carb
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?
- HawkeyeGL1200
- Posts: 918
- Joined: Sat Jul 05, 2014 11:53 am
- Location: Courtland, Va.
- Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate
Re: Single Carb
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.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?
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.
-
- Posts: 31
- Joined: Sun Oct 10, 2010 9:10 pm
- Location: Syracuse, New York
- Motorcycle: 1982 GL1100I Interstate
Re: Single Carb
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.
Re: Single Carb
here's a recent report from i'd call a key player
http://www.goldwingfacts.com/forums/348 ... st564.html
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.
-
- Posts: 31
- Joined: Sun Oct 10, 2010 9:10 pm
- Location: Syracuse, New York
- Motorcycle: 1982 GL1100I Interstate
Re: Single Carb
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.
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.
- HawkeyeGL1200
- Posts: 918
- Joined: Sat Jul 05, 2014 11:53 am
- Location: Courtland, Va.
- Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate
Re: Single Carb
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...
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.
-
- Posts: 31
- Joined: Sun Oct 10, 2010 9:10 pm
- Location: Syracuse, New York
- Motorcycle: 1982 GL1100I Interstate
Re: Single Carb
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.
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.
Re: Single Carb
that's prob a majority however there are many now and lotsa info out there, from folks who are thrilled with going and using sccHawkeyeGL1200 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...
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
-
- Posts: 450
- Joined: Mon Jan 13, 2014 6:13 am
- Location: Triplet Va
- Motorcycle: 1980 gl 1100 Std. Vetter
Re: Single Carb
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... 

My exercise bike is a goldwing.
- CaptainMidnight85
- Posts: 9
- Joined: Sat Jul 11, 2009 9:10 am
- Location: South Dakota
- Motorcycle: GL1000 - many...
'82 Interstate - Contact:
Re: Single Carb
Tom Langdon-prepped (out of the box calibration) Motorcraft 740 (Weber DFT32 licensed copy) Jessco conversion.
The Apex of naturally aspirated GL1000 Single Carburetor Conversions.
Nothing else compares.
It is the Ultimate conversion.
Convertible to a Brosol H-30/31 in minutes.
This Honda/Jessco GL1000 Apex "Super Conversion" is what All get compared to.
https://www.facebook.com/groups/JesscoM ... 9290113746
-
- Posts: 17
- Joined: Thu Dec 15, 2016 5:02 am
- Location: Portsmouth u.k.
- Motorcycle: 1976 Honda gl1000k plane Jane u.s. import
Re: Single Carb
I have a 1976 gl1000, I've just bought a single carb conversion kit over from a supplier in the u.s. I have to be honest it's beeping nothing but a severe pain in my rear end and that's putting things very politely !, I've had her in the workshop (Bike moto) of Portsmouth, several times and the guys have been very patient and read the installation instructions backwards and forwards and still the bike runs like crap, she will tick over quite roughly but at least she's ticking over..then she shudders and starts to lose tickover then suddenly all is quiet and as hard as I try she won't start...then after approximately 45 minutes of checking the bike over looking foe any issues with fuel delivery or plugs breaking down or even the Ht leads themselves showing signs of shorting out finally I give up and phone the guys at the workshop, they squeeze there other jobs around and manage to find the time to have a look at my bike and they check everything over and inside and out can't find any problems accept the bloody bike thugs and starts and won't run right.
I'm now waiting for some other jets just in case they are the problem but somehow I honestly doubt it, I think there's a problem with this whole set up and if there is then I'm going to be seriously out of pocket.
Does anyone out there who lives near Portsmouth United kingdom who can possibly help me either sort out this vs carb conversion so it actually does what is advertised to do or can help me refit the original carbs and set them up.
Unfortunately I'm not loaded and don't have infinite knowledge of engines eventhough I'm quite good with bikes on a farely basic level.
Would I go down the single carb route knowing what I now know, the answer to that question is a RESOUNDING NO given my experiences with this one kit I would advise me to stay well clear.
I'm now waiting for some other jets just in case they are the problem but somehow I honestly doubt it, I think there's a problem with this whole set up and if there is then I'm going to be seriously out of pocket.
Does anyone out there who lives near Portsmouth United kingdom who can possibly help me either sort out this vs carb conversion so it actually does what is advertised to do or can help me refit the original carbs and set them up.
Unfortunately I'm not loaded and don't have infinite knowledge of engines eventhough I'm quite good with bikes on a farely basic level.
Would I go down the single carb route knowing what I now know, the answer to that question is a RESOUNDING NO given my experiences with this one kit I would advise me to stay well clear.
- Jeffwing
- Posts: 1
- Joined: Tue Feb 11, 2020 3:50 am
- Location: Washburn mo
- Motorcycle: 1983 gl1100 interstate
Re: Single Carb
I changed to single carb and put a dodge neon coil upgrade and put a 5000 mgf capacitor to take the load off stator it cooled wires down and runs good. Good throttle response better top end fuel milage changed exhaust system so it breathes better. have done allot of research and read all I could before any upgrades so far so good recently changed all lights to led wraped pipes with header tape and also wrapped intake and directed air intake to pull cooler air. So far the bike has been doing good studying the cam upgrade and timing belts tensioner upgrade.