Large fuel leak

[montyr65]

Hi all

I have a lot of fuel leaking from my carbs on my r65. When it runs its ok, right hand carb leaks a bit but the left nothing. As soon as you stop the engine fuel pours out.

It looks to be coming out of a small hole on the outside of the carb next to a small plastic cover. The hole is part of the design as its there on both sides. I.E its not a hole from damage etc.

Has anyone had this before? I wanted to ask the question before removing the carbs etc.

Many thanks in advance. Monty

[Bob_Roller]

It's not an uncommon occurrence, you have problems with the needle valve and possibly the foam float  .

You need to remove the float bowl remove the needle check the rubber tip on it, most likely it needs replacement, they harden with age and fuel exposure .

Clean out any debris that may be in the area of the seat the the needle mates to .

Check the foam floats, they have the tendency to start absorbing fuel, after being exposed to ethanol fuel for years .

Also, a good habit to get into, is to shut the fuel tap(s) off when you are within a few blocks of your destination, just remember to turn them back on when you leave again, or the engine with start to sputter about a half mile down the road .

[montmil]

Monte to Monty...

Argh, Matey, your floats be in Davy Jones Locker

Seriously though, you likely have debris in the float needle area which is holding the needle off its seat and allowing fuel to continue flowing; engine running or not. Pretty sure the leak stops after closing the petcock?

Drop the float bowls and carefully remove the floats. The float needle will fall out so be prepared for that. A shop towel spread under the carb will help you keep track off small, falling objects. Check float bowls for debris... could be a good clue.

Flush the needle seat by turning on the fuel tap. You are running a fuel filter, I hope. Catch the fuel in a container and look for trash.

Another issue could be old, fuel-soaked floats that are no longer doing what floats are supposed to do. They would need replacing if they're sinkers.

Check the needle seat and report back your findings. [smiley=thumbup.gif]

[Rob Valdez 79 R65]

I had a fuel leak once.

It turned out I needed to replace the fuel hose.

[montyr65]

Cheers everyone, guess what i'll be doing over the next few days then  [smiley=bmw_smiley.gif]

[soc7260]

One of the joys of R65 ownership. It just happens every now an again, and like the guys say it's usually crud in the carbs.
When ever it happens to me, about one ride in 20 I usually resolve it by cleaning out the overflow in the float bowl.

[Rob Valdez 79 R65]

We should thank our lucky stars that the carburators are so easily accessed.
Imagine messing with a bank of 4 across the back of a 4-cylinder?

This is one of the things that made me want a BMW in the first place.  You remember, back when all there were, were air-cooled flat twins?

[Justin B.]

Often just turning on the gas with needles removed is not enough.  The rubber fuel lines deteriorate and little hard rubber bits that can prevent the needle from seating fully are on the "upwind" side of the seat and can only be removed by "back-flushing".  I chased this gremlin for a long time on the R65RS...