10 replies [Last post]
clay
clay's picture
 Offline
VBMWMO #9596
San Jose, CA
Joined: 11/17/2019
Posts: 8

Need some advice or direction to previous discussions on this topic.

1961 R50/S
Ran perfectly before I touched it ; )
Switched from low handlebars to high bars. Installed longer cables.

Fires up and idles perfectly. Giving any amount of throttle causes engine to bog down and stall. Sounds like its being starved, not flooded.

I pulled fuel line at the bowl and see a steady solid stream from both fuel lines.
Tested fuel flow with gas cap on and off, no change in steady fuel flow.
Fuel is new.

I'm assuming that I messed up something when I opened the carb to connect new, longer throttle cables.

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6973
How's the routing of the new

How's the routing of the new cables? Are they pinched anywhere?

__________________

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

clay
clay's picture
 Offline
VBMWMO #9596
San Jose, CA
Joined: 11/17/2019
Posts: 8
No pinching, everything moves

No pinching, everything moves freely

wa1nca
wa1nca's picture
 Offline
VBMWMO #8374
Ashfield Ma.
Joined: 09/27/2012
Posts: 637
Free Play

One carb slide may be lifting sooner than the other with the new cables
Check that both carb slides are lifting at the same time
They should have equal free play at idle
If not adjust one of the cable adjustment to match the other

Tommy

__________________

Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

clay
clay's picture
 Offline
VBMWMO #9596
San Jose, CA
Joined: 11/17/2019
Posts: 8
Thanks, I'll check the cable

Thanks, I'll check the cable free play.

Update:
I pulled the main jets and cleaned a fair amount of crud out. Cleaned jets with gasoline and blew out with compressed air. Problem persists.

Twocams
Twocams's picture
 Offline
VBMWMO #8750
Joined: 03/16/2014
Posts: 732
I know you may want to fix

I know you may want to fix yourself. But Scotties Work Shop is in Santa Clara about 5 miles from you. He works on old BMWs and restores.
He seems to be highly recommended.

__________________

Twocams
92 R100RT/69 R69S
2004 Aprilia Atlantic 500cc single cylinder Scooter
83 Honda V65 Magna, fastest production bike in1983

Daves79x
Daves79x's picture
 Offline
VBMWMO #9030
Joined: 08/09/2015
Posts: 377
I Would Say

I would say your throttle cable sync just off-idle is way off. It is the most critical adjustment for smooth running. There are lots of videos out there about how to do it, or every comprehensive shop manual describes it in detail.

R50S! Quite a rare bike. If you get too frustrated, I'll take it off your hands!!

Dave

__________________

Dave

skyler.robbins
skyler.robbins's picture
 Offline
VBMWMO #9513
Joined: 09/22/2018
Posts: 105
Any updates on this?...

Any updates on this?...

clay
clay's picture
 Offline
VBMWMO #9596
San Jose, CA
Joined: 11/17/2019
Posts: 8
Problem solved

Thank you everyone for the suggestions. Around 1pm today I resolved the problem. Every attempt to adjust the problem out failed. I used to work in Tech, whenever a computer problem couldn't be resolved I'd reboot. So I decided to reboot my carbs.
- Removed both carbs
- Disassembled both carbs completely (lots of photographs)
- Cleaned all the parts in my ultrasonic cleaner (lots of crud emerged)
- Blew out all passages with compressed air (more crud)
- Cleaned everything in gasoline
- Reassembled the carbs and installed on the bike
- Checked play in the cables, adjusted as needed
- Started on first kick and ran around the neighborhood like a new bike

PreviewAttachmentSize
c44fbc59-ac36-45b1-a638-8111482f5343.jpeg1.93 MB
  • 105e5864-dfaa-43a9-8a17-1a9582e52a5f.jpeg
wa1nca
wa1nca's picture
 Offline
VBMWMO #8374
Ashfield Ma.
Joined: 09/27/2012
Posts: 637
Dirty carbs

Glad to here you got it running well again

My friend a retired auto mechanic would always ask me what was the last thing you did and then say start their and that will most likely fix your problem

Changing your throttle cables didnt gum up your carbs

Tommy

__________________

Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

Daves79x
Daves79x's picture
 Offline
VBMWMO #9030
Joined: 08/09/2015
Posts: 377
Great

Great to hear you got the bike running well!

Dave

__________________

Dave

Comment viewing options

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