BMW R80 1987 Leaky Bing carburettor...

[Lucy]

Hello helpful Kiwibikers... when I bought the bike and first filled it up, fuel leaked from the right hand carb, after taking off the float bowl and tapping the float it stopped.

Since then I (with the help of a retired mechanic) have replaced the gasket, replaced the float valve which had a groove in the rubber tip, checked the float didn't have fuel in it, and adjusted the tab that presses the valve. All seemed good, leak stopped, until today on my first long ride when after an hour I stopped for lunch and when I came back to bike fuel was p**sing out as badly as it ever had.

It seemed to be leaking from a small pipe/tube in the middle of the carb. When I turned the tap off and waited for it to empty, then turned it on again, fuel came out somewhere else, (nearer the side with the float valve).

Any ideas? Thanks in advance....

[Lucy]

Well after much Googling and mulling over, it seems that the only thing to ever make the bowl overflow and leak is either the valve or the float. As the valve is new, I am now wondering whether on a long ride the float has time to soak up and absorb some fuel to the point where it makes the bowl leak. Does that sound plausible? I am going to swap the float with the left hand side one and see if the leak swaps sides too.

[T.W.R]

We had a R65LS in at work late last year that was suffering from the same sort of issues.
Basically to solve it we were given the go-ahead to source a complete carb kit for the bike (not sure where the parts were ordered from, sorry) but that solve the leak issues. Apart from that just turn the fuel taps off when you park the bike up.

have you checked this site out:

http://www.airheads.org/

[Lucy]

We had a R65LS in at work late last year that was suffering from the same sort of issues.
Basically to solve it we were given the go-ahead to source a complete carb kit for the bike (not sure where the parts were ordered from, sorry) but that solve the leak issues. Apart from that just turn the fuel taps off when you park the bike up.

have you checked this site out:

http://www.airheads.org/

Thanks for the link - that is one I hadn't found.

Have just read a few things on there, and I may clean out the tank and fuel filters and see if it was gunk getting through that caused the relapse.

I ran into someone with an R80 and he told me to ask for and get a carb kit too, but when I rang the shops they all said they sold all the bits seperately and not in kit form. That's why I got the gasket and float valve first. Do you remember what was in the kit?

[Bonez]

Type in "R80 carb rebuild kits" in google. There's a few sites that have them on offer. Generally just the diaphams, gaskets and O-rings.
http://www.ascycles.com/detail.aspx?ID=2688

Float level may be set too high on one side allowing it to overflow too.

Had a similar issue on my R65. Just got in the habit of putting it on the centre stand and turning the fuel cocks of when not mobile.

In saying that Dad is an anal R80 owner and hasn't had this issue ;)

[T.W.R]

Do you remember what was in the kit?

From memory the kit had, float valves, seats, gaskets, needles, & Jets.

Least with your R80 there'll be plenty of parts available as they cross-over with R100, not like the R65LS which is BMW's oddball model :mellow:

[Bonez]

From memory the kit had, float valves, seats, gaskets, needles, & Jets.

Least with your R80 there'll be plenty of parts available as they cross-over with R100, not like the R65LS which is BMW's oddball model :mellow:Of the CV carbed airheads some R100s where the odd ones out with 40mm carbs. The rest had 32mm carbs.

Bing have full rebuild kits as you pointed out btw-

http://www.bingcarburetor.com/bmw/bmwcvkits.html

They'll need the carb numbers to supply the correct items.

Theres an exploded diagram in pdf form on this page-

http://www.bingcarburetor.com/bmw/bmw.html

[Lucy]

From memory the kit had, float valves, seats, gaskets, needles, & Jets.

Least with your R80 there'll be plenty of parts available as they cross-over with R100, not like the R65LS which is BMW's oddball model :mellow:

Yeah that's true, there doesn't seem to be a shortage of bits which is good. I presume they stopped selling them as a 'kit' because of the expense - my gaskets were $8 but the float needle valve was about $40, and so I hate to think what the overall kit would cost. On the net the kits seem to be $40 all up.

AS motorcycles say they only ship to the US or Canada, I think I will try and source locally as I am getting to the bottom of this problem and don't want to fork out for bits I don't need yet.

[BlackJack]

I've got an R80 G/S which I've had for 17 years. The leaky carb syndrome has occurred probably 15 of those years but only happens after I take the bowl off to see if there is any water in it. The cure for me is to turn the gas off and run the bike till it runs out of gas. Usually by the time I have done this 3-4 times it will magically stop and then be OK again till next time the carb bowl is removed.
So, the process of emptying the bowl of gas by running the engine is allowing something to settle into a position where is seats properly. Just taking the bowl off and tipping out the gas doesn't do it. Beats me but it works! Its done it on both sides as well. Sure would like to know why.

[TygerTung]

Could be rust or somthing similar jamming under the seat?