Carb float or Passing fuel tap?

[andybantam]

Tried to start my 2ma and its putting petrol out of the exhausts as I kick it over! they were full! Could you please help,im thinking either a stuck carb float or the fuel tap is passing,where do I start? cheers.

[tzr-v4]

Problem can come from :
- perished o'ring at float valve seat => new seat needed or find o'ring (solex carburetor fits)
- perished membrane/seal at the fuel tap = vacuum does not close the fuel tap => change seals or reverse the TAP to remove vacuum mechanism.

Check on the forum I think I've posted some pictures while ago.

[andybantam]

Thanks for that,i think I will try the fuel tap first,cheers.

[tzr-v4]

To remove the vacuum functioning and get a 3 position tap... here you go :

Unscrew the 2 little philipps bolts
Turn 180° the metal plate engraved with On / Res / PRI

From memory, PRI will become OFF position.
Remember to block vacuum hose to avoid cylinder seizure.

Standard tap


Modified one

[Rasher]

I spaffed £100 on new Yamaha tap last spring and it now drips.

Tried this mod on old one and its neat, and Prime is the new off, but it also still dripped.

Took new one apart and the diagphram was sticky and horrible despite only seeing shell or esso premium, cleaned it up and OK again.

Next trick will be to jam behind the plunger to ensure it seals with reversing the plate to hopefully create a leak free on / off setup.