Update of petcock rebuild procedure 86-89 TRX350; this is my seventh one—sofar I have only found one oddball with a lever that was slightly larger diameter.
You can buy a set of seals on fleabay that includes the 4-hole packing, an oring lever seal, 2 tank seals and 2 screws. It will help greatly to use a small jewelers drill press and a set of oring probes.
Two things about this kit is that 1) I can’t find the right tap for the kit screws (3mm x 0.5mm?), so I use 6x32x3/8” screws; 2) the original petcock lever uses a quad seal instead of an oring–I haven’t followed up on the right sized quad seal because the oring fits.
I use a wooden jig to hold the petcock (with screws/nuts) while I’m drilling–it gets hot and this will help you concentrate on bit placement. I started with a #45—fits perfectly in the rivet head dimple–use cutting oil and small depths so you don’t weld the bit to the rivet. Drill all the way thru the ear of the petcock backshell.
Next use a #36 bit to enlarge the hole for the 6mmx32 tap. Take short strokes and plenty of cutting oil; back out the tap often to clear the shavings. Lastly cut the head off the rivets using a #20 bit and very shallow stroke–you want to leave a bit of the old rivet bodies as alignment pins. You can pop off the top shell cover with a flathead screwdriver–be careful not to damage the fiber shim underneath.
Replace all the seals, lubing with a petroleum compatible grease. Reassemble by seating the 4-hole packing on the backshell, then lever with seal, compression spring, fiber shim and topshell. Run the screws down firmly, but not too tight or will be hard to operate lever–no gasket sealer is needed. Took me an hour.
Oh that little piece? A rivet head.
You can buy a set of seals on fleabay that includes the 4-hole packing, an oring lever seal, 2 tank seals and 2 screws. It will help greatly to use a small jewelers drill press and a set of oring probes.
Two things about this kit is that 1) I can’t find the right tap for the kit screws (3mm x 0.5mm?), so I use 6x32x3/8” screws; 2) the original petcock lever uses a quad seal instead of an oring–I haven’t followed up on the right sized quad seal because the oring fits.
I use a wooden jig to hold the petcock (with screws/nuts) while I’m drilling–it gets hot and this will help you concentrate on bit placement. I started with a #45—fits perfectly in the rivet head dimple–use cutting oil and small depths so you don’t weld the bit to the rivet. Drill all the way thru the ear of the petcock backshell.
Next use a #36 bit to enlarge the hole for the 6mmx32 tap. Take short strokes and plenty of cutting oil; back out the tap often to clear the shavings. Lastly cut the head off the rivets using a #20 bit and very shallow stroke–you want to leave a bit of the old rivet bodies as alignment pins. You can pop off the top shell cover with a flathead screwdriver–be careful not to damage the fiber shim underneath.
Replace all the seals, lubing with a petroleum compatible grease. Reassemble by seating the 4-hole packing on the backshell, then lever with seal, compression spring, fiber shim and topshell. Run the screws down firmly, but not too tight or will be hard to operate lever–no gasket sealer is needed. Took me an hour.
Oh that little piece? A rivet head.