Draft Front Boss Replacement Procedure
Okay - I think I've come up with a version of
@dobba99 's fix that anyone with a vise/hacksaw/file can do.
I've elected to use brass, as its good in fuels and also free machining (easy to work)
Get a length of brass threaded rod (I've chosen M20 x 1.5 because I can't get 3/4" UNF - they both have similar pitch) and cut a 25mm piece and flatten the ends
Get 2 thin locknuts to suit
Get a short 5/16 UNF grub screw (preferably brass but doesn't matter if its steel)
Get 2 thin M20 copper washers (annealed) - just to cherry red and quench or not,
Next drill and tap 5/16 UNF down the centre of the 25mm piece (you can do a blind hole if you like but a through-hole is easier and cleaner).
File one of the lock nuts down to, say, 5mm thick.
Now to assemble, using loctite (567, 569 or 577), wind the thick nut onto the piece so that there is about 7mm of thread projecting from one end.
Again with loctite put the grub screw in the other end so that there is 17mm thread depth (existing boss number) for the OEM stud (only 10mm needed).
After the loctite has gone off - say 30 minutes - you're ready to fit to the tank.
First, ensure that the "boss hole" is a clean 20mm diameter and the threaded rod will slide through. Also that it's reasonably flat.
Put a copper washer onto the 7mm threaded projection
Next, snugly thread the OEM stud into the new threaded boss, having first locked 2 nuts together near the other tip.
Tie some braided (50-80ib) fishing line firmly near the tip (above the nuts) of the OEM stud and use a stick/wire (?) to poke the other end of the line through the fuel cap and through the boss hole.
Turn the tank upside-down, put some loctite on the copper washer and thread. (it is now important the job is finished within 5-10 minutes)
Pull the tip of the stud through the boss hole and use the the stud/nuts to pull the new boss into place.
Put the second copper washer and the "thinned" locknut onto the 7mm projection, with some loctite (i'd be liberal here), and tighten the locknut using the 5/16 nuts to counter the torque. Have not come up with a torque value yet - but schnisentite!
I am yet to get my bits but will report back after fitment.
Many thanks to Peter for his great idea!
Cheers ...and sorry if I've bored you all to death! (idle minds and devils you know!)
