73 Wombat retsto - Petcock

[Heeto63]

Greetings everyone, glad to be in this group!!!

I am in the midst of restoring my Wombat which I have owned since 1981. It's been tucked away in the corner for way too many years and it's time for it to live and breathe again!
In looking at my original petcocks, do they require a tiny o-ring??? Or is there a better petcock to replace these?

[Dale]

Welcome to the group!
The original petcocks do not have an O-ring. They are metal to metal. The surfaces can be lapped with polishing compounds to improve their seal, but with limited success (some folks can do it successfully). There are replacements available at Hodaka-Parts.com. There are both a brass style (like the original, but with a tiny o-ring) and a pot metal style. Both are better than the originals. In my opinion, the pot metal style is the way to go for long term performance.

Watch out for other types/brands of petcocks. The threads on the Hodaka chrome tanks are 1/8-28 BSPP (British Standard Pipe Parallel). Not a common thread for later petcocks. And, it is best to purchase a tap and die of this size to chase your threads in addition to applying a thin coating of a fuel fitting sealant on the threads (Gasoila is a good one).

[Al Harpster]

I have successfully re-lapped the original equipment type.

I've used Diamond lapping compounds, working from "coarse" to "fine". Automotive Valve Grinding compounds are too coarse from my experience.

Here's a link for the diamond compound:

https://usa.banggood.com/7pcs-Diamond-P ... mds=search

New aftermarket petcocks with the o-ring seem fine. Last I looked a pair would run about $100.

I dislike the pot metal ones, but that's just my preference.

If you like, send me yours and I will give them my best effort to re-lap and test at No Charge.

aharpster at copper dot net

PS I assume you are sure they leak. If not, try first.

[MTrat]

Check the Resonator Revisited for an article on rescuing these brass fuel cocks.

[matt glascock]

Nice Al!

[Heeto63]

Thanks for the info guys! I honestly don't remember if they leak so I'll clean and test first!