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Old 07-24-2013, 08:32 AM   #16
Rucksta
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I have a project to remove the Dels and reinstall Bings.
(to stop cable chafe when using the 43 lt Acrebis tank)

The project has been sitting on Ray Peaks bench for near two years.
Neither of us are motivated.

Has anyone ever gone back to Bings?
I don't seem to be able to find their posts telling us how excited they were with the change.
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Old 07-24-2013, 09:24 AM   #17
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Originally Posted by Rucksta View Post
I don't seem to be able to find their posts telling us how excited they were with the change.
Maybe that's telling...

- If the tops of my boots were too dry and odorless, I'd install 40mm Bings
- If I needed a constant bruise on my right mid-shin, I'd install 40mm Bings
- If I wanted to turn the gas off by kicking it, I'd install 40mm Bings
- If I wanted to twist - wait- go, I'd install 40mm Bings
- If I didn't like to use engine braking, I'd install 40mm Bings

I'm sure there are other reasons I can't pull up right now. To the benefit that they are undemanding, I would say "So is an ugly girl". The Bings are really the only thing I have ruled out. I have Mikunis on my R75/6 and they do well, but I wanted to take this build upscale from the R75 where it makes sense. Just trying to learn what is out there and what kind of trials or sucesses people are having. No bones to pick with the Bingers. I spent a few decades there.

Fuel injection! Hmmm? How to get a fuel pump into a /7 tank???
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Old 07-24-2013, 09:26 AM   #18
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I had 38mm mikunis on my 77 R100Rs and would never own another Airhead without putting them on it as well.
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Old 07-24-2013, 09:27 AM   #19
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I had 38mm mikunis on my 77 R100Rs and would never own another Airhead without putting them on it as well.
Flat or round slide?
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Old 07-24-2013, 09:42 AM   #20
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Links to this? I can find a page full of PHM type carbs on Dellortodirect, but nothing that explains what the differences are between the different models (such as BS/BD, CS/CD, NS/ND, etc.). Is there a US reseller that has the knowledge to kit one with starting jetting, cables, and connectors as a Sudco or Rocky Point would do with Mikunis and Keihins?
The explanation is somewhere in the manual. I can't remember where without going through it.

The choice pretty much boils down to Mikuni's or Dell's. Flat slides or round? The flat slide Mikuni's come with independent float floats just like Bing use to sell in their 'alcohol proof' floats. In both brand carbs that float system is very problematic. Very prone to constant flooding. Both type Mikuni's take some engineering to get them back to the airbox. The best way to do that IMO isn't that great of a setup. Plus it looks like crap. And you have to come up with cables. The airbox setup with Dell's is great. R90S cables. R90S jetting will get you started. Just lean it out from there. Performance? I would rate all three too close to tell keeping in mind that any 38mm Dell or Mikuni has way more low end and top end and everything in between than a 40 OR 32mm Bing.
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Old 07-24-2013, 01:02 PM   #21
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Quote:
Originally Posted by beemerphile View Post

Fuel injection! Hmmm? How to get a fuel pump into a /7 tank???
You could put a small non-submersed pump right beside the starter and feed it from the stock fuel crossover under the airbox.
A microsquirt injection can use the starter teeth on the flywheel for crankshaft positioning and two camshaft sensors to get the correct TDC info. With the BMW cable splitter under the tank you can drive the TPS and you can use a completely gutted Bing40 as an injector-holder+throttle-plate, and route the cabling to drive the injector through the intake air duct from the air filter housing.
Voila- almost invisible EFI mod for the airhead. (You would see the second set of fuel lines from the fuel pump to the "carbs".
(I did a project like this for a thumper, needed to be invisible because on my side of the pond it is almost impossible to get something like that through the hoops of bureaucrazy*)

Cheers

AlpineRAM

* bureaucrazy is not a typo- it's a definition for the crazy in the offices of the authorities.
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Old 07-25-2013, 03:44 AM   #22
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Hello Beemerphile,

if you want to keep it simple, you should go for the Dellortos.
Cables and adaptation to the air box readily available from BMW.
If you choose the rubber mounted version, e.g. PHM 40 NS/D (Sinistra for left, Destra for right) and want to connect them to your big-valve heads' spigots you could take these rubber mounts (from the Guzzi 1100 ie):
http://www.stein-dinse.biz/images/pr...s/01114390.jpg
They fit perfectly on the spigot and the carb.

If you don't want to have choke cables hanging around this may be an option:
http://www.stein-dinse.biz/images/pr...es/9619-64.jpg

Regarding this:
Quote:
Originally Posted by supershaft View Post
The choice pretty much boils down to Mikuni's or Dell's. Flat slides or round? The flat slide Mikuni's come with independent float floats just like Bing use to sell in their 'alcohol proof' floats. In both brand carbs that float system is very problematic. Very prone to constant flooding. Both type Mikuni's take some engineering to get them back to the airbox. The best way to do that IMO isn't that great of a setup. Plus it looks like crap. And you have to come up with cables. The airbox setup with Dell's is great. R90S cables. R90S jetting will get you started. Just lean it out from there. Performance? I would rate all three too close to tell keeping in mind that any 38mm Dell or Mikuni has way more low end and top end and everything in between than a 40 OR 32mm Bing.
A friend had Mikuni TM40 on his R90S with the stock airbox (round filter type).
Connection to the airbox was easy and looked perfect like stock.
This is the bike in question:
http://www.motoren-israel.com/images...icture2033.jpg

The floats in the TM40 are not independent. No problems here whatsoever. The carbs work great. Jetting is also easy. I could provide a basic jetting as a starting point.
Readily prepared (basic jetting set for BMW use) Mikunis and cables can be bought here: http://www.mikuni-topham.de/ENGLISHS...e_English.html)
But Mikunis and parts are relatively expensive (at least over here).
So again, if it has to be simple and cheap, I would prefer the Dells.

Best regards

RG

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Old 07-25-2013, 05:30 AM   #23
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Thanks RG,

In a couple of paragraphs you more than doubled my knowledge of the Dellortos. We are getting somewhere now. I do not mind choke cables, nor do I mind independent chokes, so either solution there would work.

You mentioned that you could provide basic jetting for the Mikunis. Would you be able to help with basic jetting for the Dells?
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Old 07-25-2013, 05:52 AM   #24
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Hello!

Quote:
Originally Posted by beemerphile View Post
You mentioned that you could provide basic jetting for the Mikunis. Would you be able to help with basic jetting for the Dells?
Yes. Like SS I would recommend the R90S jetting as a starting point.

Idle jet 60, Atomizer AB260, Needle K4, main jet 155, Slide 60/5.
For a 40mm Dell I would go up to a 165 main for the first step.
I would run it with acceleration pumps.
If set properly engine response with pumps is much better, especially from low revs.

However, depending on your engine configuration, the jetting your engine really needs may be quite different.
I'm running 55 idle jets, AB262 atomizers, K6 needles, 155 mains, 60/5 slides.

Best regards

RG
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Old 07-25-2013, 06:32 AM   #25
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Originally Posted by beemerphile View Post
Fuel injection! Hmmm? How to get a fuel pump into a /7 tank???
Don't need it inside the tank, go with an external fuel pump.
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Old 07-25-2013, 01:25 PM   #26
supershaft
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Quote:
Originally Posted by RGregor View Post
Hello Beemerphile,

if you want to keep it simple, you should go for the Dellortos.
Cables and adaptation to the air box readily available from BMW.
If you choose the rubber mounted version, e.g. PHM 40 NS/D (Sinistra for left, Destra for right) and want to connect them to your big-valve heads' spigots you could take these rubber mounts (from the Guzzi 1100 ie):
http://www.stein-dinse.biz/images/pr...s/01114390.jpg
They fit perfectly on the spigot and the carb.

If you don't want to have choke cables hanging around this may be an option:
http://www.stein-dinse.biz/images/pr...es/9619-64.jpg

Regarding this:


A friend had Mikuni TM40 on his R90S with the stock airbox (round filter type).
Connection to the airbox was easy and looked perfect like stock.
This is the bike in question:
http://www.motoren-israel.com/images...icture2033.jpg

The floats in the TM40 are not independent. No problems here whatsoever. The carbs work great. Jetting is also easy. I could provide a basic jetting as a starting point.
Readily prepared (basic jetting set for BMW use) Mikunis and cables can be bought here: http://www.mikuni-topham.de/ENGLISHS...e_English.html)
But Mikunis and parts are relatively expensive (at least over here).
So again, if it has to be simple and cheap, I would prefer the Dells.

Best regards

RG

In that photo? Those aren't regular TM40's. I wouldn't go bigger than 38's but . . . . Those are smooth bore TM's or XR600 specific TM's or something along those lines. Just regular TM40's have a much larger built in bell mouth that won't allow a late model BMW snorkel to be used like in that photo.

Floats in 'a' TM40 aren't independent? Which TM40? They are in every regular TM series carb I have ever seen.

I would use 38mm Dellorto's too over 40's but . . . . I also get them picking up revs and accelerating much harder without the pumps connected as do MANY tuners I know. That is unless you crack the throttle wide open from low rpms with a good load on the motor. The pumps will help you out of that stupidity but why sacrifice picking up revs and accelerating for masking a ham fisted right hand? That's pretty much all those pumps are good for.
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Old 07-25-2013, 02:24 PM   #27
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Originally Posted by supershaft View Post
In that photo? Those aren't regular TM40's. I wouldn't go bigger than 38's but . . . . Those are smooth bore TM's or XR600 specific TM's or something along those lines. Just regular TM40's have a much larger built in bell mouth that won't allow a late model BMW snorkel to be used like in that photo.

Floats in 'a' TM40 aren't independent? Which TM40? They are in every regular TM series carb I have ever seen.

I would use 38mm Dellorto's too over 40's but . . . . I also get them picking up revs and accelerating much harder without the pumps connected as do MANY tuners I know. That is unless you crack the throttle wide open from low rpms with a good load on the motor. The pumps will help you out of that stupidity but why sacrifice picking up revs and accelerating for masking a ham fisted right hand? That's pretty much all those pumps are good for.
Hello SS,

now what is a "regular" TM?
I'm speaking of TM 40-6 carbs.
If you are interested you can find them here:
http://www.mikuni-topham.de/ENGLISHS...e_English.html

And yes, they are flatslides/smooth bore. And yes, they don't have independent floats. If required I can provide a photo, I've got a set of carbs here.

Sometimes there are things outside we have not yet seen ....

Regarding the pumps: you have your experience, I have mine.
I have learned that you disabled the pumps and got more power.
Knowing how the pumps work there is no logic explanation for that.

Regarding the wrist: yes, I have a sensitive wrist.
And still I can feel the benefit of the pump.
I ran my carbs with/without pumps and with modified levers. So I believe I can compare very well. Without the pumps the bike ran good, with the pumps it simply runs better.

If it works for you without the pumps it's fine.

38mm Dells are in fact big enough, I'm using them as well.
However, regarding the big ports of the '77 heads this will give a strange port shape. The problem are the heads, not the carbs ...

Best regards

RG
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Old 07-25-2013, 08:30 PM   #28
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Google mikuni tm. Those are 'regular' TM carbs. I was not talking about smooth bore TM's. If I was, I would say 'smooth bore TM carbs' versus 'TM carbs'. Go figure?


No logical explanation? Give me a brake with the logic. I have had AMA National Championship winning tuners tell me that they use to do the same thing for the same reasons. Figure out that logic.

So now you are telling me about big ports?
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Old 07-25-2013, 09:52 PM   #29
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Originally Posted by supershaft View Post
Google mikuni tm. Those are 'regular' TM carbs. I was not talking about smooth bore TM's. If I was, I would say 'smooth bore TM carbs' versus 'TM carbs'. Go figure?


No logical explanation? Give me a brake with the logic. I have had AMA National Championship winning tuners tell me that they use to do the same thing for the same reasons. Figure out that logic.

So now you are telling me about big ports?
Hello SS!

1. I'd suggest we let Mikuni decide, what they call TM and what not.
2. There are no TM40 in the series you mean. The only TM40 is the one I mentioned.
3. If there is an explanation I would be eager to learn
4. No, I'm not telling you about big ports, but Beemerphile

Best regards

RG
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Old 07-26-2013, 02:56 PM   #30
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Originally Posted by RGregor View Post
Hello SS!

1. I'd suggest we let Mikuni decide, what they call TM and what not.
2. There are no TM40 in the series you mean. The only TM40 is the one I mentioned.
3. If there is an explanation I would be eager to learn
4. No, I'm not telling you about big ports, but Beemerphile

Best regards

RG
The only TM40? There's the TM40 smooth bore, TM Pro Series which come in 39 and 41mms, TM40-6's, and more.

Explanation? Better mixture.
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