Steve Saunders Goldwing Forums banner

Single Carburetor - which one?

155K views 593 replies 66 participants last post by  AZgl1800 
#1 ·
I'm running the Weber 32/36 Prog. right now.
What do you use?
What would you use?
Why?

My next project will be the Solex 30PICT-1 like the one below.
 

Attachments

See less See more
1
#2 ·
imported post

I would use whichever carb you have the most experience with and has the best reliability. Considerations are; are you interested in performance, reliability, fuel economy, or a combination of the three? I used the VW carb setup and I noticed no difference in performance and fuel milage and got better reliability. Having worked on SU, Weber, and Zenith carbs; I know there are many that can do a good job. I picked the one that I believe is the easiest to work on with the least amount of maintanance needed to keep it running properly. I'm sure there are alternatives that will suit each individuals requirements.

Bernie
 
#3 ·
imported post

Serviceability... This one will be for its "anywhere by anyone" serviceability.
 
#4 ·
imported post

So I've heard of guys who are running Holley progressive carbs. [Like the 32/36 mentioned above, BTW I don't know what the numbers indicate ??? are they jet sizes or something? and what CFM are those?]

Speaking of CFM, someone mentioned 650 CFM, but some of these carbs seem to be a lot smaller than 650, more like 165 or 175. I know it makes a difference. Is that the gas fuel/volume? or the size of the plenum?

Also is there a minimum size for a plenum? What size is recommended?

VW carbs, Solex,others, and I'm afraid I have to show my ignorance here and say truthfully that what I want is good reliability, low maintenance, and decent gas mileage. so yeah I want something of a trifecta. And if it has a little pep then that would just make me grin even bigger. I don't need to hit 100mph, but 90 would be nice.

So since I am a new guy to this technology, which carb would give me the best performance?

BTW, this is my winter project and I plan on building my intake manifold from PVC. [Completely PVC and glue, and some paint.]
Since this is a project, I'll try to document it with lots of pics as well. I already have gotten some diagrams/schematics put together and I'm looking forward to the tinkering. I think it would look so crazy to having the whole intake manifold from PVC and spray painted to look like metal. We'll see how it goes. My prices lists currently is less than $25 for parts. (not including the carb itself.)

I love to tinker. :D
 
#5 ·
imported post

I had a 70's Dodge tradesman van with a 318 CID engine and single BBL carb which was super easy to work on, very reliable and has an electric choke.
I dont know which brand carb it was and probably too big for a GW application but Dodge put a 6 cylinder in the same van so I might try that route.
Either that one or a Holley, both I'm familiar with but the Holley's I used to have trouble with the floats and seats.
Pretty much any small carb that has jetting available so I can tweak it is what I'm after.
 
#6 ·
imported post

dan filipi wrote:
I had a 70's Dodge tradesman van with a 318 CID engine and single BBL carb which was super easy to work on, very reliable and has an electric choke.
I dont know which brand carb it was and probably too big for a GW application but Dodge put a 6 cylinder in the same van so I might try that route.
Either that one or a Holley, both I'm familiar with but the Holley's I used to have trouble with the floats and seats.
Pretty much any small carb that has jetting available so I can tweak it is what I'm after.
Dang, I bought the same van 6 years ago out of a junkyard with a single barrel carb on a small V-8. Cleaned up all the gunk and dirt off the block, replaced all the plugs and wires and it ran like a champ!! I gave all of 400 for it and sold it a few months later for 800. It even still had the after market a/c setup in it and all it needed was freon.

I sold it to a guy so his yard crew would have something decent to haul the trailer with all the mowers on it. Sometimes I wish I still had it as it wasn't bad on gas at all.
 
#7 ·
imported post

grayglennsr wrote:
Speaking of CFM, someone mentioned 650 CFM, but some of these carbs seem to be a lot smaller than 650, more like 165 or 175. I know it makes a difference. Is that the gas fuel/volume? or the size of the plenum?
CFM flow for the GL-1000:
RPM @ 100%VE@ 75%VE (VE = Volumetric Efficiency)
1000 rpm = 18 cfm = 13 cfm (I say 75% for myVE, not yours..)
2500 rpm = 44 cfm = 33 cfm(cfm is a measure of demand)
4000 rpm = 71 cfm =53 cfm
6500 rpm = 115 cfm = 86 cfm
8000 rpm = 141 cfm = 105 cfm

A Weber 32/36 DGV flows 255 cfm...
The primary (32) flows about 190 cfm...
The secondary (36) flows the balance when activated.
The throttle progression is: primary = 1st 2/3: secondary = the last 1/3 (...roughly).
There is a fairly quick transition from primary to secondary.

So... knowing what the motor will flow, and its operating rpm range, tells us how much carburetor we need, and how much we don't need. (...of course it's simplified)

If the above is taken as gospel, then we see that the 32/36 DGV may be more carb than we need. Looking at Webers chart below says we're 'bout right on the money though.There are any number of variables (erroneous inefficiency is one) that allow for error in trying to calculate with accuracy. My Weber sits on a 8-rubbered Type-3 manifold, and I aint calling that efficient by any standard, but it works.
I'd be happier with a smaller carburetor on my bike, but what I've got works for now.

Here is my Weber chart with input: (others may differ)
Line #1 = redline @ 9500 rpm
Line #2 = factory spec max pwr @ 7500 rpm
Line #3 = where I'll normally highside my upshift when tooling around.
Line #4 = one cylinders capacity...

Weber has other charts, but this one is a good start for us.
 

Attachments

#8 ·
imported post

Here's a useful blank graph for the DIY'er...
 

Attachments

#9 ·
imported post

Carburetor project #2: Weber 28/36 DCD

Like this one:
 

Attachments

#12 ·
imported post

I would say that carburetor should be taken from same size car engine but if Wing has 6K red line and car engine has 4K that probably means car engine has to be 50% bigger.
 
#13 ·
imported post

dan filipi wrote:
As long as the cfm is adequate is a 2 bbl necessary?
NO.

The Solex that started the thread is a 1bbl.

The Weber 32/36 DGV that I'm using now is a 2bbl, but I think it's too big for my bike and the throttle progression has the secondary kicking in too soon on the twist.

The Weber 28/36 DCD has a smaller primary, yet maintains the larger secondary.I think it would be a better carburetor for my bike. Throttle progression has a faster transition from primary to secondary (10% transition vs 22%) and happens later in the progression >>> 1st 4/5 = primary --- last 5th = secondary.
I would stay on the primary for most of my riding with the DCD. The secondary would comeon laterin the throttle twist.
 
#14 ·
imported post

OnaWingandaPrayer wrote:
man you guys in the great white reagions have way to much time on your hands . I'll stick with four carbs and a manometer . But then in Fl we ride all year .



Good luck with your projects .

Thats a fair statement...

But,... if you don't piss in my snow. I won't piss on your sunshine.





Good luck with your four carbs.
 
#15 ·
imported post

CaptainMidnight85 wrote:
OnaWingandaPrayer wrote:
man you guys in the great white reagions have way to much time on your hands . I'll stick with four carbs and a manometer . But then in Fl we ride all year .



Good luck with your projects .

Thats a fair statement...

But,... if you don't piss in my snow. I won't piss on your sunshine.





Good luck with your four carbs.
Fair enough :cheeky1:. Actually I am moving on to two carb Goldwings . I can / do understand the want of a simpler system . If I ever get back to building a 1000 I really may try tinkering . But that wont be an everyday bike .
 
#16 ·
imported post

newbiker wrote:
I would say that carburetor should be taken from same size car engine but if Wing has 6K red line and car engine has 4K that probably means car engine has to be 50% bigger.
Makes sense.

But, for example, a Weber with a given bore size can be choked up or down, rejetted and retunedto accomodate a particular application.

One carburetor could accomodate a 4, 6 or 8 cylinder given the proper set-up.
 
#17 ·
imported post

OnaWingandaPrayer wrote:
CaptainMidnight85 wrote:
OnaWingandaPrayer wrote: But that wont be an everyday bike .

I understand...

Just doing my part...

Many older 'Wings have seen better days. When it came time for me to resurrect my current 'Wings hibernation, I had options for the carbs. I've never been a purist with the aim of factory restoring anything. A simple carb overhaul for it is not as simple as, say, my cb 350, 900, or my XL. Different animals them GL carbs are. So, weighing my options on how to attack the carburetor issue, I opted for a simpler, more cost effective route. My Weber set-up rebuilt/complete/installed cost much less than the best available GL carburetor kit out there, and performs exceptionally well. I'm happy.

A lot of fellas here have only one bike, some none. But for those that can't deal with the older GL carbs for whatever reason, I'm passing on whateverinfo I can. To some, their GL is an everyday bike.Making it worry-free (be it 4 carbs or 1) is stand-up no matter what the approach in my book.

Carburetion is fun in my house.
My 17 year old daughter rebuilt my 32/36, not because Iwanted her to do it, but because she wanted to show her 18 year old sister how to do it.It's only complicated without the proper information.


Be different, run two YFs from a 1st gen Camaro. Havn't seen that yet.
 

Attachments

#18 ·
imported post

My current Weber list:
 

Attachments

#19 ·
imported post

My current Rochester list:
 

Attachments

#20 ·
imported post

Hitachi / Holley:
 

Attachments

#21 ·
imported post

Stromberg / SU:
 

Attachments

#22 ·
#23 ·
imported post

Great ! :)
 
#25 ·
imported post

Yeah, I don't think that I would use an SU either. I'm grateful that someone did provide flow data though. I've seen some crazy stuff mounted atop a GL motor.

'Ya never know...
 
#26 ·
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top