Topic: Cracked petcock tube

[socalsupermoto]

you know that tube for the non-reserve line that shoots up into the tank (k2 cb750)? I cracked it while rebuilding my petcock. does it screw out for replacement? or is there an easy fix? ie coat it with some kind of epoxy/metal fix? other option is to just say screw it and watch my mileage since i'll be on reserve all the time.

one more question. the previous owner thought it was a k3 but it's a k2. many of the replacement gaskets are different sizes, did they change the petcock from k2 to k3?

Thanks!!!

[BeSeeingYou]

I remember reading about repairing the overflow tubes in the carb with shrink tubing.  As long as it's resistant to gas it should work.  You could solder it (use flux) or JB Weld.

[KB02]

I used heat shrink tube to repair my stand pipe on my K2 fuel valve. Be careful, though, as the reserve circuit is filled through the same hole as the stand pipe, so the thicker the tubing you put over the stand pipe, the less fuel will flow on reserve.

Solder is the best fix, or replacing the pipe, BUT, trying finding metric sized brass tubing in the US... yeah, right...

[HondanutRider]

Soldering cracks in those tubes is difficult, I found.  What I did was jam a small section of steel brake pipe over top of my cracked standing tube, and it seems to work OK.  The heat-shrink wrap sound like a better solution as its thinner (to fit into the tank hole) and won't rust, but is it resistant to dissolving in the gasoline?

[wrenchmuch]

I soldered the tube with no problem . Clean with carb cleaner first to get fuel residue off . Use plumbing paste flux and lead /tin solder for plumbing if you can find it . Lead free works as well but needs slightly higher temps to melt and flow well . Flux the tube and place the assembly so the tubes open end is inclined towards the floor (don't want solder in the valve ) . Apply the flame (low heat) to the open end of the tube and test with the solder where the tube meets the valve body . When hot enough it will begin to flow . Apply solder to the crack from the valve body towards the flame at the open end of the tube . Use the solder sparingly. Disassemble your valve first . Repair i made to mine is still good after 6 years . I don't think I would use this to repair a bowl overflow tube . It would likely fill the tube .
Hope this helps you .
Mike

[socalsupermoto]

wow great suggestions guys.

the only shrink wrap i have is the stuff used for electrical. can that withstand gas? does jb weld hold up to gas?

I'm embarassed to admit that i own a soldering gun and beyond that know pretty much nothing about soldering. (head hanging in shame)

[Magpie]

I found some replacement brass tubing at a local hobby shop. It was a tiny bit bigger than the Honda pipe but with careful use of a drill it fit.
Cliff.

[HondaMan]

+1 what Magpie said: I've also used that hobby shop brass tube, but chucked it into a drill and trimmed down one end with emery paper until it was "metric" enough to fit. 

[Magpie]

Hondaman, didn't think of doing that. Better than having an oops with the drill in an irreplaceable petcock.
Cliff.

[socalsupermoto]

how does that pipe fit in? does it pressure fit in, or welded?

I said screw it and slapped some jb weld and called it a day. I'll keep you posted as to the sucess. I think first time i ride i'll carry some gas. that way i won't put it to reserve, only to find that it was on reserve the whole time from gas going through the cracks of the tube. i think the jb did the trick though.

[BeSeeingYou]

JB Weld should hold up to gas. 

[socalsupermoto]

thanks, we'll find out!