Weber carb conversion

[RMBLOldwinger]

Hello one and all! I appreciate being here. I recently bought a 1983 GL1100 Interstate and just can't leave well enough alone. The bike has sat for awhile and even though it starts and runs, the carbs are in dire need of attention. At any rate, I am ditching the Keihins and installing a set of spanking new Weber 40IDF's. My problem is that an electric fuel pump is recommended and I have not been able to find one specific to the GL1100. Does anyone here have an idea what might work in this situation? Many thanks!

[jameselindorff]

Hello: since these were popular fits on VW s you could probably use a 12v electric pump that would fit their application. My memory fails me on the details "of the day" but I'm sure they were low pressure pumps. Beck Arnley used to sell an inexpensive pump that was suitable and small with a mounting bracket. Best wishes

[Maz]

I've been told that a Yamaha FJ1200 electric pump will work. They're cheap too!
Maz

[brianinpa]

The fuel pump for an 84 Honda Accord is almost a direct match for the 1200, so it will work with an 1100 as well.

[RMBLOldwinger]

Thank you all so much for your excellent responses! I will update when the project is finished.

[Mh434]

Just make sure it's a low-pressure pump. Webers typically don't like more than 2-3 psi pressure.

[RMBLOldwinger]

Good to know. Thanks much!

[RBGERSON]

I'd try it with the pump on the bike now..it pumps at 2-3lbs. But Any electric pump that pumps at 2-3lbs. should work just fine. Many install an electric pump right where the mechanical pump was mounted.you just need to fab a face plate for the end of the tach housing..don't forget a auto shut off circuit..based on the bikes attitude..IE if it goes down..the pump shuts off. I think the reason they spec a pump at all is that many bikes didn't have pumps they were all gravity fed..now-a-days not so much..

[RMBLOldwinger]

The primary reason that the electric pump is used is to shorten start time. Weber 40IDF's do not employ a choke circuit, so the start is done the old fashioned way.....pump the throttle a few times. The electric pump will fill the bowl without cranking the engine over, where the mechanical pump will not. This particular conversion is Gold Wing specific, so I am sure the mechanical pump was taken into consideration. I really appreciate the mention of the "auto shut-off" switch, because it had not yet occurred to me. That could, indeed, be a life saver. There are a lot of "Deep Thinkers" on this site, and I very much appreciate all of the excellent input.

I have been messing about with old bikes for many years now, particularly old Hondas, and one of my major frustrations has been the factory carbs (Keihins) on the bikes. Anytime that it is feasible I replace them with Mikunis. My recent experience with a 78 CB750 Supersport is a great example. I fiddled and fussed with the Keihins for a good three months and was never able to get them sorted out. After discovering a set of racked up Mikuni flat slides, which were pre-jetted and ready to go, I just had to have them. The difference was nothing short of amazing. I had a similar experience when I replaced the 28mm Keihin with a 36 Mik. If I could put Mikunis on the Wing, I would, but the cables would be a nightmare. The Weber conversion is not a "perfect for everyone" conversion, because it changes the riding dynamics, but after reading all of the available information on it, I felt it would work for me. It is amazing how many wacky ideas begin to make perfect sense once one cracks the "70" mark (years, that is).

[RMBLOldwinger]

Update: Thanks to brianinpa for the tip on the Honda Accord fuel pump. It is working like a charm! The project is 98% complete, and I am waiting for the air filters to come it. The initial start-up went great and the carbs settled almost immediately to a fairly smooth idle, and the throttle response is perfect. After I get the filters on and get the engine up to operating temp, I will tweak the idle mixtures a bit. They don't need much.

The forty page instruction booklet was very good, however, I did run into a few things that were not spot on. The project required some improvisation. I will post a full report on the conversion once I get it up and running and dialed in so I can give my views on the rideability (spell check didn't like that) and performance.

Thanks again for all of the response and input!

[brianinpa]

Pictures or it didn't happen!!!!!

Seriously, glad it worked. I am counting the days until I pull the carbs off of my 87 and replace it with a single carb again.

[RMBLOldwinger]

Thanks for the support!

I considered a single carb conversion, but did not find one that I liked more than the Weber conversion. However, I did not spend a great deal of time searching and most recently, I saw some conversation on a four barrel set-up. No details, and I don't even know where I saw it.

I have not had the bike out on the road yet, because my first test run was without air filters, so I didn't want to go far. I will say, however, that my initial takeaway is that power is up significantly and the seat of the pants feel was quite scintillating. Once I installed the air filters, it went rich and fouled the plugs, so I parked it until the new jet kit arrives.....hopefully tomorrow.

[JJ5484]

Would it be possible for you to shoot some pictures of the linkages that you came up with?

[Deckhand45]

Gas mileage figure?
I love Webers! Easy to work on and so damn adjustable!! If traveling across the continent and break down in, say Kansas, and all you can see is cornfields forever....
A small bag of parts that can get you runnin again?? That's great! Same with points ignition. A matchbook, diamond deb, and screwdriver...
Buy new points in the next town....
"Old school"......(ok, old school street outlaw, but still...)
So seriously looking at the Weber conversion. Can get both sets of carbs for just under 300, and can make the manifolds.and I know Webers (more forgiving) better. Resale? Too old to GAF.
Fun, and reliability, and ease of repair means more. More power and acceleration? Bonus!! And useful Especially when riding 2 up!!
But what actually has been experienced in MPG??
Thanks!

[Jonojrsa]

Hey Guys,
I hope someone is still around who recalls this topic. We are about to do a Weber conversion on a GL1100 and need to know what to do about the vacuum pipe from the pulse generators??

[joecoolsuncle]

The primary reason that the electric pump is used is to shorten start time. Weber 40IDF's do not employ a choke circuit, so the start is done the old fashioned way.....pump the throttle a few times. The electric pump will fill the bowl without cranking the engine over, where the mechanical pump will not. This particular conversion is Gold Wing specific, so I am sure the mechanical pump was taken into consideration. I really appreciate the mention of the "auto shut-off" switch, because it had not yet occurred to me. That could, indeed, be a life saver. There are a lot of "Deep Thinkers" on this site, and I very much appreciate all of the excellent input.

I have been messing about with old bikes for many years now, particularly old Hondas, and one of my major frustrations has been the factory carbs (Keihins) on the bikes. Anytime that it is feasible I replace them with Mikunis. My recent experience with a 78 CB750 Supersport is a great example. I fiddled and fussed with the Keihins for a good three months and was never able to get them sorted out. After discovering a set of racked up Mikuni flat slides, which were pre-jetted and ready to go, I just had to have them. The difference was nothing short of amazing. I had a similar experience when I replaced the 28mm Keihin with a 36 Mik. If I could put Mikunis on the Wing, I would, but the cables would be a nightmare. The Weber conversion is not a "perfect for everyone" conversion, because it changes the riding dynamics, but after reading all of the available information on it, I felt it would work for me. It is amazing how many wacky ideas begin to make perfect sense once one cracks the "70" mark (years, that is).

LOL so you are saying a gl1100 mechanical pump wont supply enough fuel to run a gl1100? seriously. where are all these youtubers and bloggers coming from? i guess stimulus money is finally running out.
BTW, the old fashion way was not to pump the throttle a few times. old timey did not have accelerator pumps. you know what old timey carbs had?......chokes! or enricheners!

[joecoolsuncle]

Gas mileage figure?
I love Webers! Easy to work on and so damn adjustable!! If traveling across the continent and break down in, say Kansas, and all you can see is cornfields forever....
A small bag of parts that can get you runnin again?? That's great! Same with points ignition. A matchbook, diamond deb, and screwdriver...
Buy new points in the next town....
"Old school"......(ok, old school street outlaw, but still...)
So seriously looking at the Weber conversion. Can get both sets of carbs for just under 300, and can make the manifolds.and I know Webers (more forgiving) better. Resale? Too old to GAF.
Fun, and reliability, and ease of repair means more. More power and acceleration? Bonus!! And useful Especially when riding 2 up!!
But what actually has been experienced in MPG??
Thanks!

hey boy! you real. see ya on da road. my boy in oilfield.

[joecoolsuncle]

The primary reason that the electric pump is used is to shorten start time. Weber 40IDF's do not employ a choke circuit, so the start is done the old fashioned way.....pump the throttle a few times. The electric pump will fill the bowl without cranking the engine over, where the mechanical pump will not. This particular conversion is Gold Wing specific, so I am sure the mechanical pump was taken into consideration. I really appreciate the mention of the "auto shut-off" switch, because it had not yet occurred to me. That could, indeed, be a life saver. There are a lot of "Deep Thinkers" on this site, and I very much appreciate all of the excellent input.

I have been messing about with old bikes for many years now, particularly old Hondas, and one of my major frustrations has been the factory carbs (Keihins) on the bikes. Anytime that it is feasible I replace them with Mikunis. My recent experience with a 78 CB750 Supersport is a great example. I fiddled and fussed with the Keihins for a good three months and was never able to get them sorted out. After discovering a set of racked up Mikuni flat slides, which were pre-jetted and ready to go, I just had to have them. The difference was nothing short of amazing. I had a similar experience when I replaced the 28mm Keihin with a 36 Mik. If I could put Mikunis on the Wing, I would, but the cables would be a nightmare. The Weber conversion is not a "perfect for everyone" conversion, because it changes the riding dynamics, but after reading all of the available information on it, I felt it would work for me. It is amazing how many wacky ideas begin to make perfect sense once one cracks the "70" mark (years, that is).

phony stuff make phony people.