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Main Area => Odds n Ends => Topic started by: 1034am on October 29, 2017, 10:47:08 AM

Title: Petcock/tank outlet relocation
Post by: 1034am on October 29, 2017, 10:47:08 AM
I am changing a CF Moto V3 to a V5 and the new gas tank won't fit due to the gas outlet fitting is in the wrong spot. What's the best way to remedy?
I was thinking of cutting out the fitting (w/some of the sheet metal around it) then either bolting or welding it to the new location. If I bolted in place, could I tap into the tank metal or would I need to back up w/nuts?
Think most body shops could do this?
Title: Re: Petcock/tank outlet relocation
Post by: Big Rich on October 29, 2017, 11:48:15 AM
It's actually a pretty complicated thing to do. I've never seen a petcock swapped over using bolts, but I couldn't imagine any amount of bolts sealing gas in.

As far as welding it goes, I have seen that quite a few times. Obviously tank prep is HUGE when it comes to welding. You'll have to call around in your area to find out who is willing to do it though.
Title: Re: Petcock/tank outlet relocation
Post by: yamahonkawazuki on October 29, 2017, 11:57:06 AM
This is true. I've w3ld3d a fuel tank before. Made me VERY nervous. Since the explosive nature of vapors.
Aaron
Title: Re: Petcock/tank outlet relocation
Post by: 1034am on October 29, 2017, 12:12:59 PM
Tank is really empty, barely even a smell.
I've tried welding before w/limited success, so that's why I was considering bringing to a bodyshop.
Wondering if I take a Suzuki style petcock and try usung self-tapping screws (w/lots of sealant!) If they're large enough, & w/thread sealant, would it be strong enough for a little 250cc street bike???
Title: Re: Petcock/tank outlet relocation
Post by: Big Rich on October 29, 2017, 02:15:22 PM
There's a process to welding gas tanks. Purging the fumes is the first step. The other problem is how thin the steel is - a normal welder will burn right thru it. Another problem is getting a good seal at the welds - I personally have met 2 people that I know can weld a tank.

I'm really just saying it's not easy. And any business that isn't 100% sure they can do it will refuse to do it because of liability issues.
Title: Re: Petcock/tank outlet relocation
Post by: yamahonkawazuki on October 29, 2017, 05:21:48 PM
indeed. i just got lucky the one time i tried. a pinhole gap  and youd have a weeper.
Aaron
Title: Re: Petcock/tank outlet relocation
Post by: 1034am on November 02, 2017, 01:17:06 PM
I have my car mechanic working on it, should know if it's good next week. Thanks for the tips - I relayed them to him.
Fingers crossed!
Title: Re: Petcock/tank outlet relocation
Post by: Joolstacho on November 27, 2017, 06:56:49 PM
Bit late now, (just noticed that this thread is a bit old), but I would: cut out the existing outlet, and silver-solder a brass patch over that hole, and then use a similar method to attach the outlet to it's new position.
Tank steel is very thin and takes a REALLY expert welder to weld it without blowing holes in it.
That's why silver solder or brazing is 'the go'
(IMHO!)
Title: Re: Petcock/tank outlet relocation
Post by: The Buddha on December 21, 2017, 06:00:05 AM
I know of several people who'd be able to weld that tank in their sleep. But I am in Nascrap country.

Fumes schumes - when you know its gas free (after several boiling water rinses) stick a match in it. If it doesn't burn up, you're home free.

Cool.
Buddha.