K
kartin
Guest
I have a 1979 GS1000E. Even after rebuild, fuel tap (petcock) was still passing fuel in "On" and "Res" with engine not running, confirming what others have said regarding quality of the kits. Tried smoothing the conical seat where the o-ring rests and also stretching the spring slightly, to no avail. I could have bought a new tap but decided I wanted a real "Off" position so here's what I did:
If you take off the piece with the lever, you'll see it has 2 channels in the inside face; a short straight and a curved. If you study the the various fuel tap passages, you'll see that the straight one carries the fuel for both the "On" and "Res" positions since it carries it from the top (On) or the right (Res) feeds from the tank to the centre hole which is the one controlled by the vacuum. From there, it goes "downstairs" to the exit. The curved channel takes the fuel directly from the reserve feed to the bottom hole whuch then goes to the exit so this one is for the "Prime".
First I disabled the Prime function by filling the curved channel with 2-part epoxy (I used JB Weld). Put enough in so it's just above the surface level (clamp the piece so the flat face is horizontal) then, when fully cured, put a piece of emery paper on a very flat surface and rub the face of the tap on it until it is all smooth and flush. Next disable the vacumm operation. I did this by removing both the o-ring and the spring from the vacuum diaphragm assembly. If there's any signs of fuel shortage, I'll remove the plunger piece that holds the o-ring completely but so far not necessary.
Et voila! Now your "On" and "Res" are "full time" and your "Prime" has become your "Off".
If you take off the piece with the lever, you'll see it has 2 channels in the inside face; a short straight and a curved. If you study the the various fuel tap passages, you'll see that the straight one carries the fuel for both the "On" and "Res" positions since it carries it from the top (On) or the right (Res) feeds from the tank to the centre hole which is the one controlled by the vacuum. From there, it goes "downstairs" to the exit. The curved channel takes the fuel directly from the reserve feed to the bottom hole whuch then goes to the exit so this one is for the "Prime".
First I disabled the Prime function by filling the curved channel with 2-part epoxy (I used JB Weld). Put enough in so it's just above the surface level (clamp the piece so the flat face is horizontal) then, when fully cured, put a piece of emery paper on a very flat surface and rub the face of the tap on it until it is all smooth and flush. Next disable the vacumm operation. I did this by removing both the o-ring and the spring from the vacuum diaphragm assembly. If there's any signs of fuel shortage, I'll remove the plunger piece that holds the o-ring completely but so far not necessary.
Et voila! Now your "On" and "Res" are "full time" and your "Prime" has become your "Off".
