Dripping Left Carb (...intermittently) "Gas Shoe"

[barcelona_r65]

Hi y'all!

Now that I resolved the problem with my final drive, another thing has popped up ... My shoe smells like gasoline!  Well, just my left foot.  Since I got my baby back from the shop, I've thought that she was running a little rough and "vibrating" more than usual  ... in fact I note it quite a bit from 2000-4000RPMs .... I went back to my mechanic and he synchronized the carbs ... with a "barometer-type" thing ... great. (but still vibrating too much ... notably so for me)

However, after happily riding to work I parked and did my daily duty ... when I headed back out at the end of the day to start her up ... she did that crazy hard start up where (obviously) only one of the 2 cylinders was firing correclty ... jerking back and forth and missing for about 15 seconds until things kicked in ... and then they both fired in sync ... great.  I made it to the 1st traffic light where I smelled gas, looked down and felt it in my socks at the same time.

I ALWAYS close the petcock/valve when parked.  ALWAYS park on the center stand ... and have only had this problem a few times. (self correcting ...both the dripping float bowl and the missing cylinder on ignition for 15-30secs...)

Now, I'm wondering.  Stuck float? ... Dirty-gummed-up needle? ... Something else?  Is it missing/fowling because it's flooded? Is is riding rougher because it's getting too much gas/bad mix? .... too rich?

Is there something I can do to check this? I don't even know how to drop the float bowl ... I know there's a retaining bracket but don't know if I can just click it off and drop the bowl ... or if it'd even help looking in there ...

hmmmm

[515_FOTO]

sounds like you have a needle not seating properly, allowing the overfilling of the bowl then the gas finding places to go--your foot--into the cylinder, ect.
This can be intermittant if the inlet needle is slightly deformed (how old is it?) or permannet if the floats are stuck or really old and don't like to float anymore.
Easy and quick thing to do is replace the inlet needles. Best done with the carbs off the bike  (thereby needing another synch job) There are lots of carb rebuild web sites for the bings. Not hard to do.

Yes, the retaining clip on the bottom of the bowl rotates out of the way and the bowl will come off, straight down. It will be FULL of gas, so be careful. You could pull it off, seat the needle by hand by holding the now exposed floats up (not too hard, just enough to seat the needle) and turn the gas on. none shoud come out, unless there is a problem with the needle, whereby gas will get by it.
In the meantime be sure to park with the petcock off, like you do, or you may find a tank of gas on the floor.
Larry

[steve hawkins]

Or it could just be the float height not set correctly.

Looks like it time for a tune up.  Balancing the carbs is the last thing you do, by the way, once everything else has been checked:

1.  Tappets - set when cold.
2.  Static timing.
3.  Set idle mixture screws (see manual 1/2 turn?)
4.  Check throttle action, make sure throttle cables have some slack when throttle is closed.
5.  Make sure your butterflies are completely closed when the throttle is closed and the idle set screw is just touching the throttle stop.
6.  Make sure your chokes are off when lever is off and on when lever is on.
7.  Start the bike up and set up your dynamic timing with a strobe.
8.  Check that the carbs are not leaking petrol - remedy.
9.  Go for a 10-20 minute ride.
10.  Using balance guages to set you idle - i.e. No throttle.
11.  Using balance gauges to set the throttle cables - i.e they should both pull at exactly the same time to ensure smooth running i=on the throttle.

Go have another ride and congratulate yourself on how well you bike runs.  

That was just an overview by the way - but good 'tick list'.

12.  Sack your mechanic as by now you will have realised that nothing on your bike is a mystery and you can do a full yearly service yourself in a morning.  Know you bike.

Steve h

[nhmaf]

Yes, do try the investigation that Larry suggests.  Sometimes it can be just a bit of dirt or a flake from the insde of the fuel hose that prevents it from seating properly, or there may be a mchanical issue like Larry indicates.  (here in the US, where we have 10% ethanol mixed in the gasoline as an oxygen-adding agent, ethanol deteriorates the inside of the old style rubber fuel lines)

If it seems to be no more than a carb bowl's worth of fuel (plus a bit from the hose below the petcock) that leaks, it may just be the float and/or needle.  But if more than that - your petcock is not shutting off fuel flow like it should.   You do want to fix this as you might end up with a tank of gasoline in your crankcase, which can do a whole lot more damage.

[barcelona_r65]

Easy and quick thing to do is replace the inlet needles. Best done with the carbs off the bike  (thereby needing another synch job) There are lots of carb rebuild web sites for the bings. Not hard to do.

Larry

Thanks Larry!
 
Sounds comforting ... except for the fact that it'd be best done with the carbs off the bike ...      

The synch is no prob, my mechanic is pretty easy-going ... but, unless you tell me that I can unscrew  a few covers and unfasten the old needles before setting the new ones into place, I'm not sure if this'd be a wise endeavor for me
1.) in the street with limited tools and
2.) with my 5-year-old son asking me if I was done yet so we could go and play in the park and
3.)not to mention my 6-month old daughter drooling on me while my wife leans over my shoulder and asks me again, and again ... "what percent of the job have you completed so far? ... how much would you say you have left?" ... etc)

Please ... a glimmer of hope? ...    Is it easy?  (I'm keeping my fingers crossed ... could be an interesting weekend)

P.S. There's no "Magic Additive" that I can run through the feed lines to "wash" the carbs an dissolve all the crap, right? .... That'd be too easy, I assume ...  :-/ ... could I give it a reasonable spray cleaning from underneath if I were to drop the float bowls? ... Gummout? Carb-Cleaner? Oven Cleaner?  :-? Hairspray?  

[Barry]

Th precribed way to set the fuel level in the carb is to check that the float needle just shuts off fuel flow with the floats parallel to the carb body.
Adjustment can be made by gently bending the tab that pushes up on the float needle. I also like to measure the fuel height in the bowls after quickly removing them. There does not seem to be a concensus on what the fuel height should be. Figures quoted vary from 20 to 24 mm.
23 to 24mm works well for me and the precise figure is probably less important than that they are both the same.

[barcelona_r65]

[size=8]Th precribed way to set the fuel level in the carb is to check that the float needle just shuts off fuel flow with the floats parallel to the carb body.
Adjustment can be made by gently bending the tab that pushes up on the float needle. I also like to measure the fuel height in the bowls after quickly removing them. There does not seem to be a concensus on what the fuel height should be. Figures quoted vary from 20 to 24 mm.
23 to 24mm works well for me and the precise figure is probably less important than that they are both the same.[/size]

  THAT ONE SEEMED TO COME OUT OF LEFT FIELD?!! ...HMMM  

[Barry]

THAT ONE SEEMED TO COME OUT OF LEFT FIELD?!! ...HMMM  

Sorry if it seemed so. As we posted almost simultaneously I hadn't seen your last question and was still addressing the possibilities of why your left carb overflowed. It could have been because your "mechanic" set the fuel level too high. I offered a way for you to check this which you could do with the carbs still on the bike.

To answer your last question is there an easy solution to your problem ?  I'm with Steve H sack the mechanic and learn to do it right.

[Darwin_R65]

Hi y'all!

Now that I resolved the problem with my final drive, another thing has popped up ... My shoe smells like gasoline!  Well, just my left foot.  

Talk about coincidences, I 've just repaired my rear drive and got the bike on the road yesterday morning, rode it to work where it backfired and I though "that's odd" then I looked down at my shoe and I have a wet look to my left boot and the carby intake hose has come adrift from the breather box. Obviously the rear drive and the left carby are attached by some cosmic connection.  :-/

call x-files

John

[dav]

Mine done the same thing but on the right carby, we put new fuel hose lines on & during the next ride the right carby was leaking fuel, just pulled over took the bowl off played with the needle & seat, but it kept on happening, all on different days but twice in 20mins on one day. Anyway i found out we used (thanks dad!!!) fuel line that had been used as a nesting place for our insects friends, but he did say he gave it a GOOD clean , sooooo we stuck the air line in the hose & blasted away. Its has't happened since (touch wood), all it takes is tiny little specks of whatever to upset the neddle/seat...

hope you work it barcelona  

[DeeG]

Please ... a glimmer of hope? ...    Is it easy?  (I'm keeping my fingers crossed ... could be an interesting weekend)

P.S. There's no "Magic Additive" that I can run through the feed lines to "wash" the carbs an dissolve all the crap, right? .... That'd be too easy, I assume ...  :-/ ... could I give it a reasonable spray cleaning from underneath if I were to drop the float bowls? ... Gummout? Carb-Cleaner? Oven Cleaner?  :-? Hairspray?  

I'm looking at rebuilding the carbs in all three of the airheads.  ACK!!!  I thought along the same lines as you:  Gumout, carb cleaner, etc.  But in the end, I thought about how long it had been since the carbs were rebuilt (in the R75's case.....19 years) and with all the alcohol that they put in the fuel now, I decided a total rebuild was best.  And at about $170 per kit, it isn't cheap either.  Oh well.  At least when its done, I won't have to worry about it for another 19 years.... hehehehe

[Bob_Roller]

Other than the throttle shaft o-rings, it's not a big job .

After you deal with the screws on the throttle plates once, it's not intimidating after that .

[515_FOTO]

I think NHMAF has nalied it--thanks to the alcohol and other crapola in our gas, at least here in the US, we all better get good at rebuliding our carbs or get use to gas soaked feet.
Removing the carbs is easily done in the street, with one tool, a slot head screwdriver.  A 15 minute job. hose clamps loosened, loosen cable adjusters till they are off,, move levers on side of carb so the end of the cable can slide out sideways (I know this sounds confusing, but wont be when you look at it) remove the bowls to get rid of the gas in it. stuff a rag in the head opening. Then take carbs in to the kitchen table. Explain to the family this is a good place to do this. (mine now accept it as a recurring ritual) Find one of the many bing rebuild procedures on the net. take digital photos as you go along so things go back in correctly. small bowl of carb cleaner to soak metal parts. compressed air to blow them out (hold onto those parts tight when doing this or you may be playing find the pilot jet)  use the right size screwdriver. do one at a time so the other one can be used as a 'where does this go' model if you get in trouble. And I am with Bob, the throttle shaft o-rings are a bear. If you do the inlet needles, diaphragms, enrichment circuit gasket, bowl gasket, and remove needles, seats, adjustment screws, ect and clean the heck out of them you are doing well and adjust the bowls when they go back on you will be living the dream. Sounds like way more work than it is. 1-2 beers max per carb.
And we are here to help.

[nhmaf]

There are now alcohol resistant fuel line hose available in the autoparts stores - it may be called something like "blue line", or it may have a blue line on it.   Some of the new vinyl fuel lines (not black rubber) are also alcohol-proof and won't disintegrate... but of course, the nuisance is switching everything over on all your bikes, lawnmowers, snowblowers, etc.

[515_FOTO]

I am also wondering if the meth/corn/alco-ohol is also effecting the tips of the inlet needles. The tips that plug up the inlet orfice is black and I always assumed it was a rubber 'skin'to aid in stopping the gas. Is our gas deforming it, contributing to this plague of overflowing carbs? Gas foot has always been a part of BMW airhead life, but it seems out of control now.

BTW, Barcelona R65--does you bike have a red pinstripe as well as the white one around the tank? Stock paint or repainted? That is the bike I am looking for for my wife. My 82 R100RT has that exact color scheme and the touring cases.