!!! CARB leak and problems !!! (Part 20 ;-))

[guyom]

HI ALL i am back again :

question 1: if you let the fuel line opens when you go for a beer, is there some fuel on the ground = YES OR NO ?
On my R65, this is the case :
so i changed the float needles... but nothing changes...
so i changed the floats... but nothing changes...
so i changed all the seals... but nothing changes...
so i changed the membranes... but nothing changes...
so i tried different setups.... but nothing changes...
so i carefully inspected the carbs for cracks.. but nothing changes...

SO ? ideas ?? hahaha... i am close to buy new carbs after spending 300$...

[jp9094]

Don't drink as much beer or close the fuel line and drink more beer!  ;

FWIW

[guyom]

haha yeah for now i have to switch off the line otherwise i can have just a sip... ;-)

[Carott]

Guyom,

Check your fuel lines for leaks. If the outer cloth is wet it is time to replace with new 7mm tubing.

Test that the fuel shuts off completely when you lift the floats by hand with the float bowls removed. The fuel flow should stop when the line on the float is parallel to the bottom of the carb body. It should not require any significant force. If it still drips after setting the level the float needle seat ma be damaged. Some people have had luck polishing the seat.

Others have mentioned problems with the overflow tube in the carb float bowl being cracked or loose. Set the float bowl on the bench and fill it with fuel to test its integrity.

Good luck,

Brett

[guyom]

HI Carott ! thanks for answer.. i forgot to mention that the line is also new... new filter also.

Indeed, the bowl are full of fuel so sounds like the needle does not stop fuel even new with new floats... i will check the seat of the float and polish it a bit with a dremel... (soft polishing ;-))

[guyom]

also got another question (yeah, leak is just one problem, got 2 problems on the carbs) =

One carb does not return to idle when i turn the throttle but stay high... (2500-2800rpm) i have to turn the idle screw to decrease the rpm and then put the screw at normal.

Is it a diaphragm problem?

[Justin B.]

On the seats I have always used a sharpened wood pencil with a little fine valve grinding compound on the tip. 

[guyom]

thanks sounds softer that my dremel idea ;-)

[Barry]

The idle hang up problem can be carb related or it can be a sticking ignition advance. Given the issue you have with carb flooding there's a fair chance that the idle hang up is carb related so I wouldn't attempt to resolve it until you have a reliable fuel level and the idle mixture correctly tuned. 

When idle hang up is carb related it's usually that the idle stop screw is opening the butterfly to far and bringing the transfer ports in operation when they shouldn't be.  Why should the idle stop screw be opening the butterfly too far ?  Possibly to compensate for an incorrect idle mixture either too lean or more likely in your case too rich.

[Tony Smith]

HI ALL i am back again :

question 1: if you let the fuel line opens when you go for a beer, is there some fuel on the ground = YES OR NO ?

I once sent a fairly intemperate letter to Bing on this very topic (yes it was that long ago in the time before emails). They replied "We do not make petcocks, we make carburettors. When you leave your bike, turn the petcocks off."

Never had a problem since, although quite why the Germans cannot design a needle and seat that works as well as the Japanese manufacturers is somewhat beyond me.

[Bob_Roller]

Are both carbs doing this, or just one ??

[guyom]

hi All thanks for your answers. So if i well understand : I have to turn the line OFF ;-)
And no just one carburetor : the left one. Also i added pictures of the set up of the new Floats ? are they correct like that ? thanks

[guyom]

another one for the float needle

[Bob_Roller]

Been 8 years since I had the carbs apart . Looks like the floats may be  installed up side down .
Correct me if I'm wrong .

[guyom]

haha well the carb is up side down, i read that the bottom of the float should be horizontal to the body of the carb... sound good... however in 5th gear = the motor cough meaning not enough fuel in the carb i think.