4 into 1 carb kits


Anything goes - doesn't fit any other category!
  • Sponsored Links
User avatar
roadwanderer2
Posts: 4111
Joined: Thu Aug 08, 2013 4:03 am
Location: sweetwater, Tennessee
Motorcycle: 83 GL1100A aspencade, previously owned, 1981 honda GL500i silverwing interstate, 1974 yamaha xs400, 1974 Honda cb450 twin cam, 1983 honda vt30, 1982 honda 700 shadow, 1972 cb750four, and my first bike, a brand new 1982 honda CM400e. and a new to me 1986 GL1200 aspencade SEi
Contact:

4 into 1 carb kits

Postby roadwanderer2 » Thu Mar 05, 2015 8:39 am



anyone have any view or opinions on these 4 into 1 VW carb kit swaps for the GL1100? other than having to work on 4 carbs, what are the advantages or disadvantages of doing this carb swap.

stuart.



User avatar
virgilmobile
Posts: 7659
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: 4 into 1 carb kits

Postby virgilmobile » Thu Mar 05, 2015 11:19 am

I have an opinion.. :D
The OEM design is to get the carb as close to the intake as possible...Much less volume of air between the intake valve and the main jet...This relates to a very fast throttle response and very accurate fuel metering...Move that distance from 8" in a small tube to some 14" and a plenum box before it gets to the main jet of a VW carb and I believe the performance will drop...
I'm sure it would still run,but how well is debatable.
The second question....The VW carb was never intended to be tilted side to side as the OEM carbs were....Tilting the carb may have an adverse effect on the fuel level at the main jet of the VW carb..The OEM carb was designed to maintain the correct fuel level during hard banking...The VW fitments "might" change...This change could affects the fuel mixture...Even a 2mm change in fuel level at the main jet can lean or enrichen the mixture....

User avatar
roadwanderer2
Posts: 4111
Joined: Thu Aug 08, 2013 4:03 am
Location: sweetwater, Tennessee
Motorcycle: 83 GL1100A aspencade, previously owned, 1981 honda GL500i silverwing interstate, 1974 yamaha xs400, 1974 Honda cb450 twin cam, 1983 honda vt30, 1982 honda 700 shadow, 1972 cb750four, and my first bike, a brand new 1982 honda CM400e. and a new to me 1986 GL1200 aspencade SEi
Contact:

Re: 4 into 1 carb kits

Postby roadwanderer2 » Thu Mar 05, 2015 11:22 am

virgilmobile wrote:I have an opinion.. :D
The OEM design is to get the carb as close to the intake as possible...Much less volume of air between the intake valve and the main jet...This relates to a very fast throttle response and very accurate fuel metering...Move that distance from 8" in a small tube to some 14" and a plenum box before it gets to the main jet of a VW carb and I believe the performance will drop...
I'm sure it would still run,but how well is debatable.
The second question....The VW carb was never intended to be tilted side to side as the OEM carbs were....Tilting the carb may have an adverse effect on the fuel level at the main jet of the VW carb..The OEM carb was designed to maintain the correct fuel level during hard banking...The VW fitments "might" change...This change could affects the fuel mixture...Even a 2mm change in fuel level at the main jet can lean or enrichen the mixture....


ok, I can relate to that.

stuart.

User avatar
virgilmobile
Posts: 7659
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: 4 into 1 carb kits

Postby virgilmobile » Thu Mar 05, 2015 12:11 pm

I guess that if you put a VW carb on the bike...well...it would run like a VW. :lol:
This is the reason performance machines migrated to fuel injectors.precise metering of the fuel mixture for each cylinder.Even the 4 carb setup can be "tweaked" per cylinder to compensate for slight differences.This can't be done with a single carb.

Al Lenz
Posts: 37
Joined: Tue Apr 15, 2014 5:54 pm
Location: Marion,Il.
Motorcycle: 1994 GL1500A Aspencade

Re: 4 into 1 carb kits

Postby Al Lenz » Thu Mar 05, 2015 12:23 pm

The centrifical force that goes with banking on a curve should keep the fuel level on the same angle as the carb I would think.

User avatar
tom84std
Posts: 493
Joined: Fri Jul 13, 2012 7:40 am
Location: Arlington, Texas
Motorcycle: '84 STD 1200
2002 VTX1800
2007 Shadow 750
69 BSA Bitsa
2004 Virago
VW Trike

Re: 4 into 1 carb kits

Postby tom84std » Thu Mar 05, 2015 12:37 pm

Back in the early 2000's a product called "Invader Kit" was being manufactured and sold for four-cylinder wings. It had a cast aluminum manifold and a nice Holley carb along with all the hardware for a complete conversion. Folks who had installed it said it was great. I've always toyed with the idea of doing that myself by fabricating a stainless version. I already have a carb rebuilt and ready. The problem is that I was able to get my four OEM Keihn's dialed in and just never saw the need. Then my bike went to a friend. A Solex Pict 34 original VW carb would work but that's a very old and getting rare carburetor type. Weber is a good choice nowdays. I'm running that on my VW trike. Ultra simple and reliable but most of all they're current and factory support/parts is available.

User avatar
WingAdmin
Site Admin
Posts: 17047
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: 4 into 1 carb kits

Postby WingAdmin » Thu Mar 05, 2015 2:09 pm

Al Lenz wrote:The centrifical force that goes with banking on a curve should keep the fuel level on the same angle as the carb I would think.


Yup. Otherwise the bank angle sensor (on bikes that have them) would kill the engine every time you went around a corner.

User avatar
tom84std
Posts: 493
Joined: Fri Jul 13, 2012 7:40 am
Location: Arlington, Texas
Motorcycle: '84 STD 1200
2002 VTX1800
2007 Shadow 750
69 BSA Bitsa
2004 Virago
VW Trike

Re: 4 into 1 carb kits

Postby tom84std » Thu Mar 05, 2015 2:33 pm

WingAdmin wrote:
Al Lenz wrote:The centrifical force that goes with banking on a curve should keep the fuel level on the same angle as the carb I would think.


Yup. Otherwise the bank angle sensor (on bikes that have them) would kill the engine every time you went around a corner.


You just can't imagine how much side-loads are avoided with a motorcycle until you ride a trike. My trike has no seat to straddle. My legs and feet are out in front of me. Without something around my hips I would easily slide off the seat. Without the natural lean of the motorcycle, steps have to be taken. Never notice such forces on a bike. If anything, on a bike it just adds to the G force pulling you down against the seat.

User avatar
dingdong
Posts: 2864
Joined: Thu Apr 08, 2010 8:35 am
Location: Oklahoma City
Motorcycle: 1976 gl1000
1993 gl1500
2004 NRX1800 Rune

Re: 4 into 1 carb kits

Postby dingdong » Fri Mar 06, 2015 9:53 am

I have no personal experience with these kits. I do know that there are probably hundreds if not thousands of successful conversions out there. VW isn't the only carb used for the kit. Webber and Solex carbs are also used.

Go over to ngwclub.com and you will find many pages of information regarding the conversion.
Tom

A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

User avatar
roadwanderer2
Posts: 4111
Joined: Thu Aug 08, 2013 4:03 am
Location: sweetwater, Tennessee
Motorcycle: 83 GL1100A aspencade, previously owned, 1981 honda GL500i silverwing interstate, 1974 yamaha xs400, 1974 Honda cb450 twin cam, 1983 honda vt30, 1982 honda 700 shadow, 1972 cb750four, and my first bike, a brand new 1982 honda CM400e. and a new to me 1986 GL1200 aspencade SEi
Contact:

Re: 4 into 1 carb kits

Postby roadwanderer2 » Fri Mar 06, 2015 10:33 am

dingdong wrote:I have no personal experience with these kits. I do know that there are probably hundreds if not thousands of successful conversions out there. VW isn't the only carb used for the kit. Webber and Solex carbs are also used.

Go over to ngwclub.com and you will find many pages of information regarding the conversion.


thanks ding, i'll take a look see.

stuart.

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

Re: 4 into 1 carb kits

Postby f1xrupr » Fri Mar 06, 2015 6:20 pm

I think it's a neat idea.......but, unless my stock carbs were flat out junk, I think I would leave well enough alone. Maybe look at it this way-stock carbs work great-single carb conversion might work. You can sometimes "repair" your stock carbs for maybe......$50 bucks?...$100...? And it will run like a new one. How much is a new conversing...$700.00~? Is that your primary bike ....what if it don't work to good...bad gas mileage...vapor locks on warm days. . .backfires really loud when you shut it off...looks kinda odd-hard to sell-no trade in value..? There was (is?) a guy on YouTube that installed one....that's cool I guess...then he put a blower under it...hey, that's way cool...right?...then, his bike threw a rod...far out man!!...but hey,....no problem-he just got another engine...pardon me if I seem like a idjet...(is that a word?). just some thoughts.....but, I am fascinated by the idea...keep us posted.
Last edited by f1xrupr on Fri Mar 06, 2015 6:22 pm, edited 1 time in total.
My exercise bike is a goldwing.

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

Re: 4 into 1 carb kits

Postby HawkeyeGL1200 » Fri Mar 06, 2015 6:21 pm

I studied making the conversion from 4 carbs to a single carb for quite a while. I had heard so many horror stories about how unreliable Goldwing "flat four" carbs are... so when I got my 1200, I started looking for an alternative to the apparent inevitable failure of my carb set. Well, there's almost 80,000 miles on the bike, 17,000 of which I am personally responsible for, and the bike runs fine.. even with ethanol in the gas. My 1100 has about 75,000 miles on it, and it runs fine. So, I put my single carb project on the back burner.

Results probably are as varied as are the designs people use to get from 4 into 1 carburetor on a Goldwing. I only read information from one guy who said he had put his 1000 on a dynamometer to measure how well his conversion functioned. In addition to the single carb, he had performed several other mods that probably enhanced his engine's performance, so it's hard to know what impact the single carb had overall. He designed and built his own runners and heated the runners by wrapping them in insulation allowing the elbows to conduct heat into the runners and plenum to keep the fuel charge centered within the runners. I know it is a common believe that fuel icing is the reason runners and plenums need to be heated, but as far as I know it has more to do with efficient fuel charge flow through the runners than it does with icing. Cold runners will certainly allow atomized fuel to condense on the runner tubes and make for an erratic operating engine, but I've never read about any real evidence that icing occurs.

I can look in my notes and provide links to where you can get a manifold (plenum) and of where to buy a brand new carb that apparently is the correct size (CFM) and properly jetted for the 1100's and 1200's right off the shelf. The carb runs about 100$ and I think the plenum is about 70$.. then all you need is runners (some use flexible conduit (PVC) others use aluminum tubes (1 1/4" seems to be the right diameter) and I've even seen hose used to make runners, held in place with hose clamps... but the hose tends to collapse under load after it gets hot and it's hard to heat... Some have fabricated a chamber on their plenums to pipe coolant into the underside in order to thoroughly heat the plenum and the runners (conduction and insulation) for better fuel movement. It always seemed backward to me to heat the intake manifold, and I've not really wrapped my brain around why it is better to do it. It's just one of the things in life that I've decided to take on face value and not question it after reading what men have written on the subject... men who forgot more about building engines than I will ever know... so let it be said that I agree the manifold and runners need to be heated some way.

Pretty much to a person, everyone I've discussed this with (who have actually done it) love their bike more after having done this conversion than before... of course, their bikes may have run so poorly that anything would be an improvement... so If I do decide to do this, I'm keeping my factory carb set just in case I need to send them off to Old Fogey to get them rebuilt and put back on the bike...

I suppose there is an upside and a downside to everything we do. If I had a 4 cylinder Goldwing with trashed carbs, I'd definitely give this serious consideration. I'm fortunate that I don't find myself in that situation at the moment.


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.


Return to “Goldwing Chat”




Who is online

Users browsing this forum: No registered users and 3 guests