6 replies [Last post]
yeshe
yeshe's picture
 Offline
VBMWMO #7822
Joined: 09/08/2010
Posts: 5

I have a matching #s 1965 R50/2 (manufactured October 27, 1964). I bought it last fall with about 48,000 miles on the odometer. The bike seems very original. It hadn't been started since the 1980s. I got it running without much trouble before winter came on but thought it best to have the engine gone through since I didn't know the state of the slingers. It was warm today (I'm in Montana) and I decided to pull the carbs. I found that what the bike has is a 1/26/71 and a 1/26/76. I think the R50/2 should have a 1/24/149 and a 1/24/150. From what I have found on the Internet, the 1/26/71 should be for an R50S and the 1/26/76 should be for an R69s. As I said, the bike seems very original; both valve covers have four fins, rather than the two fins that I believe would go on the "S" models. I can't say that the bike ran well or poorly with the carbs it has on it. I just took it around the block. One of the carbs had a float problem so I shut it down. I am a novice with /2s. Does anybody have any thoughts about what is going on with the carbs on this bike? I assume I should start looking for a 1/24/149 & 150 pair. Mark

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6540
You're correct on your

You're correct on your assessment of the carbs you have. The Bing book indicates that R50/2 carbs could be 45/46, 131/132, 145/146, or 149/150. Probably the later carbs would be best...there are subtle changes in some of the jets and needle positions depending on the year.

I don't know if the two studs that stick out of the heads are the same dimensions on an R50/2 versus the bigger R60/2 or R69S. But it would seem to me that the 26mm throated carbs you have would have some problems mating with the true R50/2 heads, given that they're designed for 24mm carbs. Possibly, the stud holes are the same and your 26mm carbs have some kind of reducer inside.

I would think that the larger carbs wouldn't work as efficiently as the proper carbs would.

Are your cylinder fins rounded in front and behind as they go around the circumference? The 500cc bikes had rounded fins whereas the R60/2 had fins that came to a point. Just wanted to be sure you're dealing with a R50/2.

BTW...I sent you a private message.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

RobertGephart
RobertGephart's picture
 Offline
VBMWMO #7886
Joined: 12/29/2010
Posts: 40
r50 carb numbers

I purchased a 1961 r50s last week and noticed that the right side carb # is 1/26/71 and the left is 1/26/76. What do you make of that?

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6540
According to a Bing manual

According to a Bing manual that I can find, the 71 is a carb for an R50S while the 76 is a carb for an R69S. All the settings are the same except the needle jet is different for the R69S application. If the manual is right, the 71 carb has a jet #1208 while the 76 carb jet is #2108...I don't think that's a misprint. So, it would seem that you could ensure that the settings are correct for the R50S application and things should work fine.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

RobertGephart
RobertGephart's picture
 Offline
VBMWMO #7886
Joined: 12/29/2010
Posts: 40
Carb jet #1208 & 76 carb jet #2108 settings

How is the jet # identified and do you think I could ensure the correct settings of two different carbs on the same bike?

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6540
The only Bing manual I find

The only Bing manual I find on-line is something a long-time poster here has up on his website:

http://www.flickr.com/photos/roundel/66174400/

The jets should have numbers etched into the base of it. It's impossible AFAIK to determine anything about the needles. I've never seen any numbers...they're pretty complicated with the taper, etc. Not sure if Bing can help with that. Probably best bet might be to order new ones anyway. The needle bounces around in the jet and wears out. So, you end up with a bigger hole for the gas to flow through. Most people treat them as wear items over time.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

RobertGephart
RobertGephart's picture
 Offline
VBMWMO #7886
Joined: 12/29/2010
Posts: 40
Carb jet #1208 & 76 carb jet #2108 settings

Thanks again for your help on this. I have not yet driven this bike, as there is still snow on the ground up here. I will post what I find once I get into the carbs. Attached are a few photos.

  • r50s left carb
  • r50s right carb
  • r50s left carb

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.