Leaking Carb

[Danno]

What is generally the cause of a leaky Bing carb at rest. I've not the pleasure of having one apart and mine is periodically leaking. Is a repair kit available?

Dan

[MrRiden]

Typically it's the float needle not sealing due to a spec of foreign material between the needle & seat. Drop the bowl, remove the float and have a look for wear on the needle or flecks of dirt in the bowl itself. Also a good time to check the petcock screen, fuel line condition and contemplate a fuel filter if you don't have one already. On fuel filters I prefer a paper element in a metal case. Lots of folks use the sintered bronze element encased in plastic but I had one melt so I don't use 'em anymore.
It could also be a problem with the float i.e. no longer buoyant or bent and rubbing / hanging up in the bowl. At any rate, it's always a good Idea to close the petcock whenever parking. A garage full of gasoline fumes greeted me when I failed to do this at one point! So pop the bowl & see what's there! Repair parts are readily available at most of the usual on-line sources or directly from Bing at: http://www.bingcarburetor.com/bmw/bmw.html
They have a diagram there. Parts 40 & 42 are the float & needle respectively.
rich

[Justin B.]

I have had a case where the fuel line was deteriorating internally and little hard rubber granules were causing the needle not to seat BUT I could not see them until I "back-flushed" through the seat and all kinds of black grit came out the nipple where the fuel line attaches!  This was after buying new needles, floats, etc...  I no longer use rubber line and have switched to clear tubing...

[Rob Valdez 79 R65]

And are you turning off you petcocks as you get near your destination?

This lowers the level of fuel in the bowls while the bike is parked.

You should also use the centerstand for "long-term" (longer than an hour) parking.  
Exceptions being uneven surfaces, of course.

I still use the braided rubber fuel line, but I replace it every 2-3 years.  

[drewboid]

Besides grit under the needle seat the floats have been known to become saturated and sink.
Check Snowbum's web site for lots of info on hte carbs.
http://bmwmotorcycletech.info/techindex.htm

[Yikes]

Do check that fuel line first.  It's amazing many problems are due to the simplest of causes. It's a cheap and easy fix.  Even if the outside of the line looks OK, it may be cracked on the inside, especially if the bike has been sitting for a while.  You should also look at replacing cork bowl gaskets while you're at it.

By the time you're done you will be an expert at popping the bales, pulling off the bowls and replacing them without tools and without spilling a drop of gas.  

Good luck with your fix!

John

[Danno]

Thanks guys for easing my mind. I can do Mikunis in my sleep but have never had a Bing apart. The R65 and I have not been getting along lately. Started not starting so after a battery and a new starter now the battery light is constantly on. Just great.

[Justin B.]

Then again the float level might need adjusting and/or the carb may not be "level".  You should probably start a new thread for your charging issue as if the "gen" light does not go out by about 1200 RPM, or so, it indicates your charging system is not putting out...

[montmil]

... your charging system is not putting out...

Oooh... Reminds me of my ex-wife. [smiley=Oscar.gif]

Sorry. That was inappropriate and not very PC. But, gosh, I feel better. Carry on, lads.

Monte

[Rob Valdez 79 R65]

... your charging system is not putting out...

Oooh... Reminds me of my ex-wife. [smiley=Oscar.gif]

Sorry. That was inappropriate and not very PC. But, gosh, I feel better. Carry on, lads.

Monte

But I'll bet you don't suffer from depression and anger management issues!  

[drewboid]

Danno - just a dumb question - did you disconnect the battery ground BEFORE you removed the front engine cover?
If you didn't it could have shorted against the diode board and blown some of the diodes. That would prevent the systemn from charging.  

[Danno]

The charging issue is resolved. When I removed the diode board to get at the starter bolt, I didn't realize that where was a 3 lug connector on the back so it didn't get plugged back in. But yes, I did disconnect the ground. In another thread someone stressed the importance of disconnecting the battery before doing anything.

[Danno]

Took the float bowl, etc off last night. After flushing I noticed a black chunk of something which may have been the culprit. No leaking after reassembly. Question: I noticed the needle has a definate seat mark on the rubber end. Do people generally rebuild the entire carb or replace bits and pieces? In this case the needle and seat. At the prices for parts for these little devils it's hard to justify rebuilding the whole thing.

Dan

[montmil]

... Question: I noticed the needle has a definate seat mark on the rubber end. Do people generally rebuild the entire carb or replace bits and pieces? In this case the needle and seat. At the prices for parts for these little devils it's hard to justify rebuilding the whole thing. Dan

Doesn't necessarily mean it's worn out. Just that is has been in contact with its partner doing its job. If it ain't broke, don't fix it

With your leak issue corrected -most likely a bit of fuel line- ride the bike before jumping to a conclusion and investing unrequired work/expense/time.

You may wish to consider replacing all your rubber fuel lines as it appears that one or more are deteriorating internally and will continue to shed small bits.

Monte

[Rob Valdez 79 R65]

You may wish to consider replacing all your rubber fuel lines as it appears that one or more are deteriorating internally and will continue to shed small bits.

Monte

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