TK 26 fuel leaking

hardrockminer wrote: 1. Yes, but as the fuel level increases in the bowl you will get increasing pressure on the float valve to remain closed. If fuel continues to flow after the valve is closed then you most likely have a bad match between valve and seat. You should check to see if there is any dirt or varnish on the valve seat that might prevent the valve from closing properly.

2. Depends on whether the petcock is open or closed. If open then the pressure is a result of fuel height in the tank. If closed, and it should be closed when the bike is not running then you must have leakage past your petcock. Either replace it or rebuild it.

3. Maybe...refer to item 1 above.

4. Correct.

5. The fuel system is tolerant of some errors so things don't need to be exactly according to spec.

When you set your fuel level did you check to the top of the meniscus or to the bottom? How did you measure the distance?

vabi wrote: I've checked from the top of the float bowl (clear tube test 6 mm +/-1). It's 6, give or take 0,5 for me (vernier caliper).
There is no petcock now. Carbs are on the bench and DIY IV is attached as a fuel source. So, 24 hours of consant pressure. They start leaking after 10 or so.

hardrockminer wrote: The floats on my bikes are all older than 40 years. And they don't sink.

Nessism wrote:

vabi wrote: I've checked from the top of the float bowl (clear tube test 6 mm +/-1). It's 6, give or take 0,5 for me (vernier caliper).
There is no petcock now. Carbs are on the bench and DIY IV is attached as a fuel source. So, 24 hours of consant pressure. They start leaking after 10 or so.

I'd call it done if they seal this well. The petcock will turn off fuel when the bike is parked, or at least it should.

F64 wrote: Not quite sure if you have access to a laboratory supply in Croatia.
Could you fill up the carbs with your iv setup. Then replace the iv bottle with a burette filled with gas.
The burette will be more accurate concerning fluid loss, but that's if you can get a burette for cheap.

shop.brand.de/en/volumetric-instruments/burettes.html

Nessism wrote:

vabi wrote: I've checked from the top of the float bowl (clear tube test 6 mm +/-1). It's 6, give or take 0,5 for me (vernier caliper).
There is no petcock now. Carbs are on the bench and DIY IV is attached as a fuel source. So, 24 hours of consant pressure. They start leaking after 10 or so.

I'd call it done if they seal this well. The petcock will turn off fuel when the bike is parked, or at least it should.