petcock

[stockman]

does anyone know where and which petcock rebuild kit to use on an 83 ?
Thanks

[stockman]

I guess no one knows. I'm too cheap to buy a new one. I could always add a lawn mower shut off if there is enough space.
Thanks anyway. Happy Motoring.

[Rob Valdez 79 R65]

This Topic was moved here from R65 Technical FAQ/Procedures by Rob Valdez 79 R65.


Maybe someone will see it here in the general technical area.

There are two different petcocks.  You need to determine which you have - a Germa or a Karcoma.

You can buy parts here: http://www.bmwhucky.com/010016.html


This subject was just discussed: http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1277245768

[Bob_Roller]

The Germa fuel taps have a small screw that holds the lever onto the tap, the Karcoma taps have a solid lever no screw .

That's the quickest way I know to tell them apart .

[stockman]

OK with that info -mine is a Germa. thanks again.
Being the petcock leaks would that contribute to the bowls leaking. I know the float level should stop the flow but can't it overfill?

[montmil]

OK with that info -mine is a Germa. thanks again. Being the petcock leaks would that contribute to the bowls leaking. I know the float level should stop the flow but can't it overfill?

If the fuel valve is internally shutting off all fuel flow through the fuel line; if the floats are adjusted properly and are not sunk due to fuel saturation; if the float needle valve and valve seat are clean and not being held open by a small bit of debris; if the float bowl gasket is fresh and undamaged; if the carbs are positioned vertically in the rubber tube mounts and the bike is not stored on the side stand, the carbs should not leak.

Best overhaul the petcock and then work your way down the fuel line and through the carburetor/s. It does not take but a minute bit of dirt to create a drippy leak off the carb.

I'd be betting on the needle valve and seat...

[Bob_Roller]

The floats should shut off the fuel, if they are not, the rubber tip has probably gotten hardened with age and with posibbly 31 years of contact with fuel .

I just ordered the rubber disc that was grooved on my Germa fuel tap, there's also a thin stamped sheet metal part that gives the lever it's detents .

That part appears to be no longer available and I guess it is prone to breaking .

So you probably need to open the tap up and see what parts you have that are worn out .

Motobins has a rebuild kit for the Germa fuel tap, but it doesn't have the metal disc included .

Motobins part number : 98580, cost 7.5 GBP

http://www.motobins.co.uk/bmw-parts.php?model=R Series 2 valve Twin

[stockman]

I removed both carbs and turned them upside down and checked and adjusted the floats as described in the Clymer book I have ( keeping the float parallel to the carburetor body and the  float tab just touching the needle valve) . It took a couple of try's but  I think I got it. I forgot to mention that the engine was missing and the float bowl were intermittently leaking. When I took off the left carb there was actually fuel pooled in the cylinder intake. Hence the petcock allowing the over fill situation. After the adjustment it is running smooth again.  I read Monte's post some where about carb adjustment , listening and feeling the exhaust output for balance so it is running good. I removed the fuel line for tonight and plugged it so it wouldn't over fill and for safety until I can repair/replace the petcock. I was disappointed that it started running bad Saturday, I just finished fabricating brackets to  mount some plastic Ammo cases as panniers and we were out shopping when it started missing. I really like this bike. Its more comfortable than my Vstrom 650- I want it to be as reliable. Thanks for your help.

[Rob Valdez 79 R65]

Are your fuel lines the kind with the braided cloth on the outside?

Do you know when they were last replaced?  If you don't, you should replace your fuel line while you are in there and ordering parts.  

Or, you can use fuel line available locally, but others will have to tell you about that.  I like the cloth stuff, and I'm willing to replace it every few years, because it does break down and leak, and then you think you have a petcock leak or a float leak...  Go ahead, ask me how I know.

[stockman]

Yes I have replaced all but the piece from the TEE , through motor to right side. I will pick some up after work and do it tonight. Can I just pull it through the motor housing or is more dis-assembly required? I'm ok with that if so.
Thanks to all you experts.

[montmil]

Can I just pull it through the motor housing or is more dis-assembly required?

I used a straightened coat hanger wire, run through the fuel line, to pass the line thru the airbox.

Monte

[Bob_Roller]

Lube the fuel line with some dishwashing detergent, makes it a bit easier to get the line into the engine  case .

[montmil]

Lube the fuel line with some dishwashing detergent, makes it a bit easier to get the line into the engine  case .

That's right! Otherwise, it's a lot like pushing a rope uphill.

[Rob Valdez 79 R65]

Take the airbox off.  

[Bob_Roller]

"Open' the square holes in the airbox casting with a small file, don't need to take much off to make it work .