Topic: cracked pet cock tube

[GRock]

Hey all,
My early '70's pet cock has a longitudinal crack going down the side of it. The tube seems to be in the pet cock body real tight and I'm wondering if I can just sleeve it. Has anybody seen this problem before? Searching the post doesn't yield anything so I'm thinking this is a bit unusual. Any suggestions would be greatly appreciated.
Thanks,
Greg

[smashedmelon]

Which model?
Is it the metal "nipple' protruding from the bottom of the bowl thats cracked, the bowl itself or the tube running to the carbs?

[HondanutRider]

My CB350F had a similar problem.  It still was able to suck fuel, except the reserve was pretty shot as the bottom of the tank portion could get through that crack (slowly) even in the normal Run position.  What I did was slip a small section of steel brake line tube over it and sealed the entire exterior with some tank liner (POR-15), as I was in the process of doing the tank.  Just make sure that the hole that it goes into the tank is plenty large enough - mine was.

[wrenchmuch]

I also had a crack in mine (750 K4 ) . I put some plumbing solder flux on it and soldered the crack . If you do this keep the open end of the tube facing down when you solder .

[Hoosier Tom]

I replace mine with brass tubing from the hardware store.  The OD is slightly bigger, so I chuck it in a drill and use a file to taper the end.  I've done this on several petcocks over the years.  Sometimes the old tube is so bad it crumbles when you try and twist/pull it out.  I use a screw/bolt extractor after cutting it level to the body.  Works like a charm.

Good Luck- HT

[GRock]

Hey guys,
Thanks for the input! All sound like great alternatives. As far as what model it is - it's a '78 CB750 but I'm not into the '77 '78 tanks so I picked up an early '70's tank (with the pet cock) from the local motorcycle salvage yard. The tubing I'm talking about goes up into the tank. It's rusty on the inside and the guy told me to stay away from the tank liner products because they peel off and get stuck in the pet cock and cause all sorts of problems. I guess you haven't had those problems HondanutRider? He told me to put a bottle of white vinegar in there for a few hours and slosh it around every few minutes. The vinegar will take the rust out if it isn't to heavy. If vinegar doesn't work, use CLR. What are the comments on that? As far as putting solder on it wrenchmuch, my crack is spread apart and I wonder if the vibrations would cause it to re-crack. Hoosier Tom, like that idea too! I'm keeping all ideas on the table and see what happens this weekend when I work on it. By-the-way, one of the brass nipples the the fuel lines hook up to is missing. Any ideas on where to pick up another one of those?
Sorry for all the questions, first bike and the whole newbie thing. Again, thanks for the suggestions, they all sound quite good!
Greg

[HondanutRider]

It's rusty on the inside and the guy told me to stay away from the tank liner products because they peel off and get stuck in the pet cock and cause all sorts of problems. I guess you haven't had those problems HondanutRider?

Do a forum search on "tank liners" and I'm sure you will find lots of info that collaborates with what you've been told - except for the POR-15 product.  This liner is the best, in my and many other's opinion.  Just be sure to follow all the instructions if you use it.

[flybox1]

the WORKS toilet bowl cleaner does a great job on tank ust.

[Duke McDukiedook]

What is a pet cock? Is this some type of cock that is a pet?

[HondanutRider]

What is a pet cock? Is this some type of cock that is a pet?

Actually, it's all one word: petcock.  In the English/British region of the world, the common term for gasoline is known as: petroleum, which is shortened to just "pet".  Also, the common/old English term for a valve, is "cock"  (like what was originally placed onto a barrel of brew after the "bung" was knocked-out).   Combining the two you have "petcock", which for those non-savvy translates to a "gasoline valve"...you know, that thingy at the bottom of the gas tank that turns off the flow or switches to the reserve.

What do you call it? 

[Frostyboy]