Boxerworks.com

My 1982 R100CS had a problem with the right side carburetor. At speed, it would "weep" a bit of fuel from (evidently) the gasket between the carb body and the bowl. My right boot was what alerted me to that malady. The carb did not leak when the bike was standing still even if it was running. Well, it was leaking at one point but I found that to be the needle/seat valve. I also installed a new cork gasket between the body and bowl.
Now, it doesn't leak but it must be doing a tiny bit under some conditions, or else why would my right boot give off a gasoline smell?

I'm thinking of rebuilding a pair of Dellortos I have and installing them on that bike if I can't figure out this problem with the Bing.

Have any of you all ever had and cured a problem like this?

Chuey

Is it possible that your right foot position and size may be creating an aerodynamic situation of low pressure in the area of the float bowl overflow? I seem to remember a thread a while back about right foot stinkyness.

You need stall strips for your boot apparently.

are you sure it's weeping from the gasket?
or is it from the overflow?

Maybe the float is heavy and sinking, and the fuel level is too high.
While standing still, the fuel isn't sloshing in the bowl, and if the level is just below the overflow, you won't see a leak.
But while you're riding, a small amount could be coming out of the overflow tube.
Just a thought.

from:
http://bmwmotorcycletech.info/bingcv-2.htm

Actual bowl fuel level check:
Turn the fuel off, remove one float bowl, empty its fuel into the tank (look for globules of water, if any, toss the fuel someplace, like your cleaning tank or can), replace the bowl, turn gas on, allow bowl to fill (10 to 15 seconds), turn gas off, THEN remove bowl quickly & squarely. Measure the fuel depth from the center bottom to the fuel top. I suggest using a thin, narrow, machinists steel rule. Do your best to have the bowl sitting flat & level on its base, & estimate the best you can with #1 eyeball (yes, will still be meniscus errors), the exact height of the fuel from the bottom. For the 32 mm carburetors, use 24 mm fuel height. For the 40 mm carburetors, use 28 mm fuel height.

Steve in Golden wrote: ↑Wed May 09, 2018 1:22 pm You need stall strips for your boot apparently.

Steve, I'm not sure I would know how to handle it if my boot/foot took off! I've already had a few rough landings.

Chuey

Seth, I did check the floats when I worked on the carb not but a few miles ago. But I did not check them that way. I will give that a try. I will probably use a vernier caliper that has the prong dealy that I can project into the bowl. Thanks. I'll report back on what I find. It may be several days.

Chuey

Easy to measure the total depth of your bowl, subtract 24/ 28 mm and then scribe a line on the inside of the bowl at the remainder level, around 1/2' on a 32 mm carb is usually near enough.
You also have to check one side at a time, replacing the first bowl and refilling the system before removing the second bowl, or the hoses drain into the second bowl more than the first.
FWIW mine tends to leak at anything much over 22 mm unless the carbs are set pretty level, and it goes fine set there, the way my carbs are set up, which is rich!
Choke is usually first to show me if the level is too low, it has to pull up too, through a far more restricted system, but my driveway has a around 25% slope up!

Whew...... I thought maybe they found another tRump porn star affair.

• Like everyone else, I like to work on the carb on the bike. But this keeps you from detecting small bits of old float bowl gasket stuck in place. You do need to remove the carb every once in awhile simply to check that gasket surface.

• If it's been over 10 years, then you really should replace the floats and float needles. Both get damaged over time. Take the time on installation to check the float level.

• A brownish varnish can build up on carb parts during storage. If this occurs on the float needle seat, then even a new needle can't make a good seal. If you see the varnish on the insides of the float bowl, then you need to assume you have it inside the jets and float needle seats. I highly recommend the use of a fuel system cleaner, like StarTron.

http://www.starbrite.com/startron

I did take off the carb about a year ago and replaced the bowl gasket and needle. I also checked that the float was turning off the fuel as I recall. It has not been ridden much at all since then.

Thanks to all. I will probably get a chance to work on it tomorrow and will report anything I find.

Chuey