Vacuum Petcock Shutoff

[Paul Martin]

I'm now the proud owner of a 2001 RSV (bought about a month ago).  I see in the owner's manual it says to shut off the petcock between rides.  And that surprises me.

First reason for the surprise is this bike has a fuel pump.  So, if you forget to shut off the petcock, can the fuel actually leak past the fuel pump, up to the carbs, and then leak down into the cylinders and beyond?

Second reason for the surprise is, my 1982 Yamaha XV920 is equipped with vacuum shut-off petcocks.  Why would Yamaha not equip the RSV with same?  And along with this question, has anyone here tried swapping out their RSV petcock for a vacuum shut-off petcock?

Thanks for feedback!

PM

[vzuden]

Fuel will drain past the pump.  If you have a stuck float needle,  fuel will drain into the combustion chamber and likely hydro lock the engine.   There have been some ruined engines because of this.

i had this happen once but was very lucky, the cylinder with the raw fuel happened to have the piston at the top of its travel.  When I hit the starter it was locked rather than starting to turn over and slamming that piston into uncompressable fuel and busting the piston,, rod and or block.  I took the spark plugs out,and turned over resulting in fuel spraying all over.   The crankcase usually fills with fuel too.  
Now I absolutely never shut my bike off without turning off the petcock.   I don’t even think of it as it is now such a habit.  The reverse when starting - turn the fuel and pull the choke out 

[Paul Martin]

On my '82 Yamaha XV920 I never had to worry about the petcock unless I needed to flip onto reserve.  Call me spoiled and lazy, but I went ahead and swapped out the manual petcock on my 2001 RSV for a vacuum operated (automatic shutoff) petcock.  Hopefully the below link will work - the video shows the petcock working.

20250420_043309000_iOS.MOV

Here's the ebay link to the petcock I put in:

https://www.ebay.com/itm/404012437230

 

Edited April 20 by Paul Martin
Added link to part.