hi all, new member to this forum and asking my first question. I'm in the process of restoring a '72 LT2 my son grew up riding for my daughter and having the, often seen, leaky petcock issue. I've tried some of the petcock rebuild kits seen on ebay with fairly miserable success. In looking at new petcocks there seem to be some vast differences in the price with some at about $10 up to $60 (Partshark). I recently bought a new clutch cable on Partshark and it's looked to be a genuine Yamaha part...perfect. That said, I'm wondering if anyone can point me to a reliable site for a solid petcock that isn't so expensive. Usually you get what you pay for but this little gem is nickel and diming me to death. Appreciate any replies.

I am unaware of any genuine Yamaha petcock rebuild kits. Was there a manufacturer given for the one you bought? When I rebuild a petcock, I buy genuine Yamaha parts, and I buy the screws and mounting fiber gaskets as well. I also clean all the metal parts with a soak in Berryman's carb cleaner. It's more expensive, but I've never had a Yamaha petcock rebuilt with Yamaha parts fail to seal completely.

Pretty sure its this style & can't go wrong with the price. Have bought a few similar off 'aliexpress' that work ok.
www.aliexpress.com/item/1005002130072393...924e-489ce64dceb3-26

Ebay has dozens and dozens for in the $8 range with free shipping.  I can't recommend a specific one but I've used them without issues.

Hint: 78-81 DT175 uses the same "thread on" petcock

In fairness to Yamaha the recent kit I tried was for a Honda (can I say that word here) and it wasn't genuine parts. The aluminum in the Yamaha LT2 petcock, I have, has experienced some level of electrolysis in the bowl and body above the bowl with severe pitting. I did have it in a B-9 dip for a several hours. The mating surface for the lever, where it really counts is borderline and may still be ok with a rebuild. I was just thinking it would be safer to buy a complete unit. I was mainly looking to know if my best bet is to pony up the big bucks or if anyone had a good experience with any other options. I appreciate your recommendation that using genuine parts and rebuilding the one I have may be the best, least expensive option. 
 

That's a good option for the '79 DT100 which I have also. I think I tried the petcock from that tank onto the '72 tank and recall the threads were slightly different. I do like the ability to add tension from the rear locknut on this version. I may disregard my desire to keep it original in this case if the swap carries over. I'll check it again. Thank you.

I hadn't noticed the tension bit, how trick is 'that'.

Threads are not different.  Yamaha petcock part number is the same for the LT2 and the 78-81 DT175  I have both model bikes.

I also noticed you said 79  DT100.  I doubt it would be different but it could be.  The 78-81 DT175 isn't.  Reason I mentioned the later DT175 is because an ebay search will turn up a lot more choices than LT2 will