possible solution for one of the petcock failure modes

[So Cal Joe]

New to this discussion so the petcock is vacuum but does it have a manual on/off/reserve setting like other ones onj other bikes? If so can the problem be avoided by simply turning the petcock to OFF every time you park the bike? 

[derm]

Unfortunately, no. The positions are
1. Prime (forward), which draws from the reserve height and is open without restriction
2. On (down position), which is opened by the vacuum valve, drawing from higher in the tank to allow for some reserve fuel below this height.
3. Reserve (back position), which is also open by the vacuum valve but from lower in the tank

[So Cal Joe]

Thank you I appreciate the answer. It should be easier if Kawasaki put an OFF position on the thing.

[Chrome Megaphone]

I "reconditioned" mine and fuel leaked from the switch so I gave this a try, looks exactly like OEM in every way and I now have peace of mind. Replacing the petcoc on these old bikes is now preventative maintenance. $30
https://www.ebay.com/itm/313781928845

[Nigel]

Most hydro lock events and damage occurs when the petcock is turned to ON. I  fail to see how any of the above suggestions can prevent hydro lock.  There is only one  solution which  has been known  to work 100% of the time and has also  been known to work for  over 30 years   now  and is  also a very  simple solution  and inexpensive  to implement. Why are we trying to re invent the wheel here? 

[m in sc]

there is no 'off' position. If the o-ring on the diaphragm fails, its bent rod time.

[Chrome Megaphone]

Doing this every time you stop is 100% effective

[Chrome Megaphone]

Overflow tubes are a no-go for me.  I'll rather not have a garage-house fire
A stand-alone vacuum switch inline would be a simple and inexpensive redundancy but the only make them for 1/4 in fuel systems
 

[George R. Young]

Overflow tubes are a no-go for me.  I'll rather not have a garage-house fire . . . .

Without overflow tubes, the gasoline fills the cylinder then trickles out onto the same floor with the same fire hazard.

[Chrome Megaphone]

So best to avoid both. 

[m in sc]

again.. manual inline cut off is the only sure fire way to prevent both IMHO. (as i have stated above)

[Boomer]

I've found that a new vacuum petcock every 10 years or so works wonders.
Yes it might leak one day and total my engine, but I've managed well over 300k miles on 3 different C10s and so far no hydro lock.
I've rebuilt two high mileage C10 engines and both had straight conrods.

[m in sc]

Mines done that way because they do tend to sit.. a lot. I don't use them every day by a long shot, i'm typically riding my other bikes.

[Chrome Megaphone]

I "reconditioned" mine and fuel leaked from the switch so I gave this a try, looks exactly like OEM in every way and I now have peace of mind. Replacing the petcoc on these old bikes is now preventative maintenance. $30
https://www.ebay.com/itm/313781928845

Updating: took off tank yesterday and fuel would dribble out, I withdraw recommendation.