The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: steve hawkins on September 28, 2013, 11:36:42 AM

Title: Wet foot - petrol leaking out of carb
Post by: steve hawkins on September 28, 2013, 11:36:42 AM
All of a sudden I have a wet foot and am stinking of fuel.  The left hand carb seems to be leaking.  Had a spare cork gasket but that made no difference.  Float actuation seems to work.  But obviously not all the time.  Looks like the fuel is not shutting off when the float bowl is full.

Before I pull the carb for a full strip down has anyone any ideas?

Cheers

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Title: Re: Wet foot - petrol leaking out of carb
Post by: k_enn on September 28, 2013, 11:49:17 AM
check to make sure the float still floats and has not take on gasoline/petrol.
Title: Re: Wet foot - petrol leaking out of carb
Post by: Luca on September 28, 2013, 12:06:40 PM
Take the bowl off and open up the fuel tap.  If there is a piece of debris that is keeping the needle from sealing against the needle seat, this might flush it away.
Title: Re: Wet foot - petrol leaking out of carb
Post by: davidpdx on September 28, 2013, 12:35:39 PM
I have had my carb leak a few times on my foot just at startup and I got it to stop just by wrapping on it hard with a broom stick.

Title: Re: Wet foot - petrol leaking out of carb
Post by: quixotic on September 28, 2013, 09:28:36 PM
Both of my carbs had bad leaks recently.  Found out that the floats weren't floating.  Now I have new sets in there and I'm trying just to use Shell V-Power gas (0% ethanol, which doesn't soak into the floats).  So far, so good.
Title: Re: Wet foot - petrol leaking out of carb
Post by: steve hawkins on September 29, 2013, 07:44:46 AM
Well it was oil change time, so I changed the oil and filter.  Whilst waiting for the oil to drain I checked out the left carb again.  When I first looked at it, I did fiddle with the float tab, but I also found that tiny wire clip that connects the float tab to the float needle had come adrift and might have stopped the float needle from being seated correctly.

I have now put it all back together and run it up and down the street with no leaks.  It remains to be seen if this does not re-occur.

Chucked a bucket of water over it as well.  Here she is, gone to lower renthals, which I prefer to the standard high rise bars and found some mirrors from an R75.

Now its time to see why the R100 is leaking fluid out of its final drive again.  Same place, brake spindle.  Got some O-rings.
Title: Re: Wet foot - petrol leaking out of carb
Post by: montmil on September 29, 2013, 09:23:22 AM
Quote

Slightly off leaky carb topic but still Airhead...

Just completed stopping a gear oil drip outta the final drive on my R100S. Did the same fix on my '81 R65 couple years ago:

That big, ol' oil seal fitted to the Cardan cover was worn out. Seems a PO had packed way too much bearing grease -not moly grease- into the cup portion of the rear splines. I cleaned out all the excess grease and found enough dirt and grit to ruin the seal's seal.

When I did the R65, I also replaced the O-rings on the brake cam shaft. Been dry now for many moons. The R100S has no provisions for O-rings but also does not have any opening to the final drive oil; just a stright through passage but requires occasional cleaning and greasing the brake cam shaft. Both ways a bit of a PITA.

Never been fond of all those "air vents" on the rear drum, either.

Title: Re: Wet foot - petrol leaking out of carb
Post by: steve hawkins on September 30, 2013, 03:47:30 AM
It was a busy day.

But both bike seem to be okay-ish.

The R65, I think would benefit from new float and needle. I am not sure how old they are.  I am sure I replaced them on the original café Racer build back in 2001.  

Although I have stopped it leaking - eventually.   I have had to reset the float tab.  I must remember to get the carb as level as I can as well, but I am not quite sure about the result.  I might now have the fuel level too low in the bowel I will monitor it for now.

As far as the R100 is concerned it is now not leaking, however, I was working on a slightly sloped driveway, but even I was surprised on how much transmission fluid I spilled when I took the spindle out.  The spindle is the same level as the filler bolt, but of course the swing arm and the bike itself was on a slope, so I need to drop the rest of the fluid and that of the swing arm and replace and check what comes out.  just in case it was over filled or I have a leak from one to the other....it does not leak though and there is still plenty of fluid in it though.

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