Fuel Petcock: PRI / ON / RES What Do They Really Mean ?

[chief]

When in doubt check the website first!!! <LOL>...

On the website under MODS/TIPS - air and fuel -

Here's the word from that listing

The pet cock on the 800 drifter has 3 positions... PRI (Prime); RES (Reserve) and ON. This is a vacuum operated valve so when the bike is off, the valve is automatically OFF. Use the PRI position only to prime the valve after maintenance, etc.

Prime is used to fill the bowl, bypassing the vacuum system and shouldn't be used during normal operation.

So, you should be using ON, unless you start sputtering with a low fuel condition... then it's RES.

Cheers.

[Homey237]

I did not get an "owners manual" with my recent 800 Drifter purchase but I have one on the way.  In the mean time, I was on another forum website and read the "PRI" on the petcock is for "prime" (?).  RES is for reserve and ON is for normal driving fuel supply.

When is PRI used ?  Any explanation of this setting is most appreciated.  Thanks