WEBER 28/32 TLDM

[TheWheel]

I've seen some mention of the WEBER 28/32 carb on this forum and wonder if anyone has tried this for a single carb conversion or has an opinion on it as a candidate.

MODEL 91 SF 9510 EC / 6703198 from Mk 4/5 Ford Escort.

I have an opportunity to pick up a new one cheaply.

[82aspy]

tried a goog that didn't come up with much,

i wouldn't consider an unknown carb when there are carbs that have a ton of info in comparison, that continue to have issues of their own

i suggest researching fully all aspects of scc setups, before throwing money in that direction, which can easily turn into a can of worms

[TheWheel]

I wouldn't consider an unknown carb when there are carbs that have a ton of info in comparison, that continue to have issues of their own.

The known to work carbs such as in this thread http://www.ngwclub.com/forum/viewtopic.php?f=47&t=49727 are much more expensive in the UK than in the US as with so many things. If we import stuff from the US it ends up being expensive because of import duty, shipping and value added tax. Someone mentioned the Weber 28/32 in this forum and I found one on Ebay here in the UK for the equivalent of $50. A Type 3-4 manifold Center Section can be bought for about $100 add bit to that for pipes and clamps and for under $200 I could have something to get my bike, hopefully, running.

Currently I have a 600 pound paper weight in my garage with two sets of rebuilt OEM carbs either on it or on the bench. I really need to get the bike running so that I can get it through its safety test and get the thing registered for UK roads. What started out as a cheap project is turning into an expensive mistake so I do take your advice very seriously and realise that if I am going down this road I ought to decide if I'm just doing it out of desperation or if I want to commit to a single carb setup. And, if I'm committing to a single carb setup I ought to use the existing evidence to make a proper decision.

Many thanks

Phil

[ericheath]

If you have two sets rebuilt, I would focus on another problem which likely will prevent the single carb to work well. To bad you didn't know someone with a good running bike who'd let you put your carbs on for a test. Then you would know where to focus your efforts. You are new to GL's?

[TheWheel]

If you have two sets rebuilt, I would focus on another problem which likely will prevent the single carb to work well. To bad you didn't know someone with a good running bike who'd let you put your carbs on for a test. Then you would know where to focus your efforts. You are new to GL's?

Yes, new to GLs, I have a R1200GS and had R1100RT and R1150RT before and for a short while a Triumph Speedmaster in between. I like boxers and shafts!

The second set was supposed to be the good running set that I just fitted, synched and then moved on but this was not to be.

The two sets I have behave 100% differently and I've been through all of the basics, cam belts, ignition timing, valve lash, spark, air leaks. It looks like the variable is the carbs. One is impossible to synch because it revs at 3000 plus when I have them in synch, the other only fires on one cylinder. Both are quality rebuild jobs as far as I know but the complexity of four carbs makes finding other possible faults almost impossible to track down. On another forum someone suggested making up a manifold with plastic pipe and trying a single carb as a trouble shooting step. But I'm now thinking I should perhaps consider this as a permanent step to reduce complexity now and in the future.

I have a lot of time and more money than I planned in this bike having sorted the fuel tank rust, brakes, front forks, lighting, electrics (mostly) etc. on the misguided assumption that I would be able to get it going. I've spent more time going over and re going over everything to try to get it running than I put into sorting the fuel tank, brakes and mechanical basics. I've had a friend who has long experience of sorting old British bikes helping me for many hours.

One cylinder is down on compression due to rings(established fault using oil test), that is the one that is firing with the newer rebuilt carbs. I was hoping to run the bike for a few hundred miles and see if that righted the engine that has been sitting for a quite few years. If only I could get it running OK.

There's a complication because it is an unregistered import so if I get it going I can't use it on the road until I get it through a safety test. I don't even know if the gear box and clutch are good!

I'm not really sure which way to turn but was thinking if I could remove the carbs as a variable and then isolated something else I might be able to make progress.

Thanks

Phil

[82aspy]

given your circumstance, i'd try out a 50 buck rebuilt carb, in the cheapest way possible, you may get it to run good enuff to get you by, or who knows..

pretty much no info on it tho gw wise and a huge prob when getting away from a known carb is limitless variances in other similar carbs that no one knows how suitable, or not,

not to mention even known carbs having a poor history and track record

[ericheath]

Did you ever bench synch? If your base carb (the one which the others are set to) is open just a little, you will be synching all the others open as well and end up with a high idle, because synching just brings all of the other three carbs to the same as the base. I have pretty good luck setting the first carb just as close as it can to being fully closed. Remove the elbows so you can see. I try and cover half of the one forward hole, of the three holes in the bottom of the throat by the butterfly. Then adjust the next one to it as close as you can to it. Then do the same on the other side. Then start it up, warm it up. If it won't idle, turn the idle screw in until it does.

If this doesn't work, my money would be on a vacuum leak.

[TheWheel]

Hi Eric,

That is a really sensible suggestion and a zero cost thing for me to have one last go at.

The set that came with the bike look like they have been abused by someone, possibly the mechanic who was given the task of trying to get the bike going by the importer immediately before I bought it. It looks like they got frustrated trying to get #3 to close and tried to physically force the issue with a spanner and screw driver pushed against the throttle plate of #3. I posted pictures and others thought the plate might be bent but on close inspection I don't think that it is.

The problem I have is I can't seem to be able to get #3, the fixed base carb, to close up enough. Or I wasn't able to until I have just made some adjustments. See attached picture. It is difficult to get you head round the idea that the synch screws do not just adjust the throttle of the carb that they are adjacent to. For beginners like me the fact that the screw near to #4 just, in effect extends the throttle link arms and therefore changes the amount of throttle opening both on it's own side and on the right is for me counter intuitive, but I understand it now. My problem was that even with the #4 screw fully adjusted #3 would not completely close, the stop behind the main throttle pivot wheel (or whatever it is called) was stopping that wheel moving around sufficiently to allow the throttle linkage arms to extend enough to close #3 throttle. I've asked elsewhere how to sort this but didn't entirely understand what to do to sort it.

throttle-link.jpg

tab.jpg

stop.jpg

This is what I have done. I have carefully bent the tab I've marked with a B on the attached pics and the main idle screw arm that I've marked with a C. This allows the main throttle pivot wheel to turn more clockwise and in effect extends the throttle link arms. I now have more adjustment available and can fully close the #3 throttle. I am away from home this weekend and so will not be able to report back until Monday on whether this fix has actually worked. I am hopeful that I will be able to get the bike idling at a reasonable level and have resigned myself to the fact that it will not run anywhere near perfect until I have a few hundred miles done on it to hopefully free up the rings and more equalise the compression (#2 is 130psi and the others are 150). If I can get some control of the idle and get the throttles a little more in synch I will be happy.

Many thanks

Phil

PS I still think that I will try experimenting with a single carb in the future but my motivations will be different.

[ericheath]

If that arm, the one you labeled C was stopping the throttle without the choke pulled, it was really bent. That is your control of how much fast idle it gets for starting when cold. From the factory, it was around 3000. As that cam on the other end of it is rotated, it kicks the bellcrank around a little. I set mine for 2000. I just don't like them revving that much when cold.

Perhaps the previous mechanic/sales assistant forgot to install it in the right sequence and just bent it to install without having to remove the proper parts. Hop that's it for you.

[TheWheel]

I figured that the only way I was going to be able to close the throttle on the base carb was to allow the main throttle linkage "wheel" to move around further clockwise. In order to do that I bent "B" a little but then the throttle stop screw had no clearance so I bent "C" back to give me some clearance. I couldn't see how else to do this.

I suspect that someone has put a spanner on the nuts on the throttle shafts at some time and has messed up the tabs with the synch screws on them.

In his top carb rebuilding mistakes page Randakk has:
24. Failure to check / set fast idle free play (between transfer link on plenum and fast idle ramp on carb #4)

I asked elsewhere how to do this and was told about bending the little tab at "B". I couldn't see any other way to be able to close #3 enough to have a good starting point for synching the others to.

I'm intrigued to know how to remove the proper parts to do this. I can't see how the throttle link wheel can be disassembled or how to change the position of the synch screw stops. The synch screw assemblies look like they are fixed permanently to the throttle shafts. Is there another way to do what I have done?

Many thanks

Phil

[ericheath]

Hope that was your problem.

[TheWheel]

Eric, you beauty!!!

Your suggestion got me to investigate how to start with #3 closed and I've now got a bike that runs very smoothly idling at around 1100 rpm with the carbs very close to perfectly balanced. I'm absolutely stoked.

Thank you for providing the catalyst.

Best wishes

Phil

[82aspy]

[Old Fogey]

well, back home now and got the internet working again.

Glad you have managed to find a solution, although it's beyond me that you could not get the #3 throttle plate closed, when I could.
For the static synch, I have the quadrant spring off and then I synch the #1 to the held tightly shut #3 by adjusting the synch screw until it is also shut, #2 to the tightly shut #4 and then #4 to the tightly shut #3.
This works almost every time; the only time there are real problems is when the bushes wear in the operating arms of the later carbs, or I am dealing with early 755s with the sprung arm ends.
I did not find any problems doing exactly that with either set of your carbs, or obviously I would have fixed it.

[TheWheel]

Hi John,

If it wasn't something that should have been right I think it would have been easier to find. I've learned so much through all of this and have been forced to double and trebble check everything, valve timing, ignition timing, valve lash etc etc that I now really understand and have precticed how to do these things.

It has all been a very frustrating but in the end worthwhile process.

Best wishes

Phil