any advice for setting the carburetor float height for slide bing (r50/5)

[mmccullough]

Hello

I recently bought a 72 R50/5 (first BMW)
It had sat for a little while so I disassembled and cleaned the carbs (with deluxe rebuild kit)

I have a question (issue) with what is the correct float height?
The Bing book and Clymer say to adjust the height so float arm is parallel to carburetor base (~0.4" from base). This is significantly different then how the old floats I took out were set. They were set so the floats were at about a 15 degree upwards angle (as seen on bike). My issue is that if they are set parallel to the base then the Ticklers (fuel enrichener) do not reach the top of the float So they can not be used to add additional fuel for cold starting (ie no "choke')
This seem to me like there might be something is wrong (eg tickler to short?) or I am misinformed

FYI, I also installed new coils, plugs, wires, points and condenser and have had it running (a little rough) with both old float height and 'correct' height I say running a little roughly as in I have not had much experience balancing the carburetors and that may take a little practice to get correct I have not checked the value clearance and know I need to. It is the next thing I am going to do
But back to the float height, any advice? or any thought?

thank you for your time
cheers malcolm

 

[20774]

Welcome, Malcolm! If you have some downtime or want to check out things, drop over to Snowbum's site...extensive info there:

https://bmwmotorcycletech.info/technical-articles-list.htm

He has a specific article about the early /5 CV (constant velocity) carbs here:

https://bmwmotorcycletech.info/earlybingR75CV.htm

While that doesn't cover the slide carbs (Type 53), he mentions that the fuel height is around 19-21mm when measured at the center depression of the bowl. Turn the petcock(s) on, fill the bowl, turn the fuel off, then drop the bowl. Generally you're original method should be more or less in the ballpark. I would think that the fuel height in the bowl is most important for proper running, so the fuel drawn into the carb isn't too rich or lean. But if there's a problem with the ticklers, it doesn't seem right to adjust the floats to compensate for that. Could be the ticklers are the issue.

He has a link to a new float system for the Type 53s:

https://bmwmotorcycletech.info/bing-tech-bulletin.pdf

 

[69zeff65]

Look for an Air Head tech day

Malcolm, Great choice for your first BMW motorcycle. The R 50-60/5 series are a very reliable and simple to maintain/work on bike so long as you have a good information resource. The AirHeads club is a great resource.

You really should start with basics on the bike. Set the valves, gap and install correct spark plugs, check (replace if needed) points, check (replace if needed plug wires and caps), make sure your throttle cables have a good basic setting.

You have the tickler type carbs (The OP posting) so you don't have to worry about the choke cables and all that crap. You have to make sure your your carbs are clean and the jets are all properly clean and seated. Check the idle air jet to make sure Uncle Ethanol has not gummed it up.

 

[mmccullough]

Thank you - good info and advice

Thank you!
you guys are awesome

Great info and good advice

The link to the No 1/1984 Bing tech-bulletin explains that with newer floats "the tickler becomes ineffective as a starting aid" This matches what what I observed and clears up and questions about whether to follow the manual or match the settings found on the bike during disassembly (too lean)
Again, thank you,

Okay so I will reset the floats, and check the value clearance And then, practice synchronizing the carburetors (fun!)

And as for an Airhead Tech Day, that, I think is exactly what I need. I will admit to being little reluctant to dig into this guy too much (I might find a stripped head bolt or something) But I the little I have done has been fun and I am very impressed with my little airhead

cheers and again thank you
-m

 

[ccolwell]

And as for an Airhead Tech Day, that, I think is exactly what I need. I will admit to being little reluctant to dig into this guy too much (I might find a stripped head bolt or something)
-m

Dig! I learned a lot from my airheads. Fixing those stripped threads is just one more box to be checked.