R65LS 1982 carb leak

[jgp1854]

Had BING rebuild both carbs this past spring, installed BING's gas line.  All has been well, now I'm getting a minor pooling on the throttle return spring bracket, that eventually drips onto the garage floor.  I've replaced the bowl gasket to no avail.  Re-checked the floats, and needle valve, both seem to be spot on.  Did some close examination and noted where the gas line slips on over the "brass" nipple some dampness, which  in theory run down the outer lip of the top portion of the carb and collect at the bracket???

I doubt if the leak was BING line, it is very, very snug, and requires some serious tugging to remove it.  My question is: has anyone experienced the "brass" nipple leaking?  It looks to be pressured fit.

What is the CW on OEM gas line vs. BING's line?

Thanks

Jim  

[Session101]

are you using clamps? i think if you're using the stock black cloth fuel line my bike came with clamps, i use the translucent blue fuel line now its 1/4" and i don't use clamps and never had any leaks.

is it on both carbs? or just the left carb?

[jgp1854]

No clamps, using BING gas line, not the OEM fabric line.  Only the RH carb.

Jim

[fbenach]

I had the same problem a few months ago... there was a dripping specially when I turned the engine off...

The diagphram had a small hole that caused it... could it be that?

[jgp1854]

I doubt that it is the diaphragm, seeing BING just rebuilt both carbs installing new ones.

jim

[Mike V]

Jim,

Check the brass intake nipple's fit into the carb body.  It's rare but occasionally the press fit can become loose and leak.

Only other thing I can think of besides the fuel line itself is; there's an overflow port opening just above the nipple at the inside corner of the BING plate.  Just might be the float needle is hanging up with the bowl attached and the excess fuel is exiting the port opening.  Have a close look at the needle attachment on the float tab and it's clip to make sure everything is free and not hanging up.

Float settings set correctly?

[montmil]

... Float settings set correctly?

... and no bit of debris keeping the float needle from sealing all the way? Sometimes, a tiny bit of fuel line -downstream from a fuel filter- can come adrift and cause carb leaks. Even with the petcock turned off, there is still residual fuel in the lines just waiting for an opportunity to mess with you.

Been there. Still have the t-shirt.

[Ron_S.]

How much fuel is supposed to be in the float bowl?  I've heard 21 mm and 25 mm.  

[Ron_S.]

Sorry.  32 mm Bing on '86 R65.  

[Mike V]

Ron-Jim,

I've personally never measured the fuel height in the bowls.  I have a static/crude way of setting the floats, some may agree and some may disagree but I've always had good luck with my procedure.

With the floats assembled and the bowl off - I take a spare clean fuel line and attach it to the fuel intake spigot.  While lightly blowing through the fuel line I raise the float to be parallel with the carb body. If I hear the air from the fuel line stop at that point I'm good.  If not I adjust the tab to the point where I hear the escaping air  stop when the float is parallel.  I will then follow-up with an individual carb wet test. With the bowl removed and the fuel lines from the tank attached, and a collection pan beneath the carb, turn the petcock on and raise the float parallel to the carb body.  The fuel should stop flowing at that point.  If not - I make an additional tab adjustment.

Obviously; take precautions with raw fuel in your workspace.  Be sure to do one carb at a time and have a collection device for the fuel.  No open flames - ensure adequate ventilation.  I've always had very good luck with the air procedure and only once that I can remember having to make an additional adjustment on the tab after the air routine and setting.

Sometimes "shade-tree" works well.

[Ron_S.]

Thanks, Mike.  Unfortunately, for right now "shade tree" is what I have.

[Barry]

How much fuel is supposed to be in the float bowl?I've heard 21 mm and 25 mm.

I recall 22 - 24mm being the correct height. It's difficult to check accurately as you need to the whip the float bowl out of the way quickly otherwise the residual fuel in the fuel pipe adds to the contents. That can cause an error of several mm in the measured height. The exact level between 22 and 24mm is probably less important than both carbs being set at the same height so at least with new floats maybe the parallel shut off method is a better option or at if you measure the height in the bowls cross check that with the parallel method.

Truth is there is no way of being absolutely sure that the levels are correct when the bowl is on the carb short of a transparent float bowl or a sight tube. One of these days I'm going to do something along these lines.

I did read about one guy who removed the carb tops, diaphragms and main jet/needle jet assembly then poked a flexible tube into the float bowl from above. It's then possible to suck up the fuel and make a sighting U tube by bending the tube down below the bowl and back up again.

[jgp1854]

Okay,

Here is what I've done, per BING:

Check float needle to ensure not hanging up, and fuel flow is shutting down, DONE.

Checked float levels, appears to be spot on.

Replaced BING BAI fuel line with BMW OEM braided line.

Switched float bowls with friend.

Replaced float bowl gasket x 2.

Tightened hose clamp twice, and rotated the screw mechanism on the hose clamp to the top, just in case!  

Bottom line, fuel is still pooling at the bottom of the return spring bracket!

I know it isn't much, but it is the dam principle, they shouldn't leak.  Prior to having them rebuilt by BING, (at the cost of $425.00 USD) the LEFT carb leaked, after having them rebuilt the RIGHT carb is leaking.  I know of nothing else to check or do, so it appears I'm stuck with taking it off, and shipping it back KANSAS to see if BING can fix what they created.

If you have any other ideas/suggestions I'm all ears.

Borderline P..... O.. in Michigan

73516

[Bob_Roller]

Could you post a picture of the fuel leakage leakage area, I'm just having a bit of difficulty envisioning your problem .

I've looked at my bikes and I'm lost on this one !!!

I thought of an unorthodox (and possibly hazardous) method to test the carb ff of the bike .

If you have a work bench vise, put the carb into it, with a piece of wood at each end to prevent the carb body coming into contact with the vise jaws .

Put a two foot length of fuel line on the carb inlet nipple, support the fuel line so it is straight up, to get a bit of pressure to it .

Put a small funnel into the fuel line, pour some fuel into the funnel and see if the leak becomes visible .

[donbmw]

I would do the check Bob said . If it leaks on the it should leak on the bench also.