Would a faulty petcock affect the motor that much?
07-21-2008 | 01:59 PM
#1
Thread Starter
Senior Member
Superstock
Joined: Mar 2007
Posts: 268
From: San Diego
Would a faulty petcock affect the motor that much?
I remember the first time I took my tank off, I didn't have to twist the dial, as I read the guides on here that it's vac controlled. One day I twisted it off, and when I twisted it back on fuel started pouring out. I'm guessing I tore an o-ring or the diaphragm assembly.
Anyway, would this affect rich/lean conditions while riding?
Anyway, would this affect rich/lean conditions while riding?
07-21-2008 | 02:59 PM
#2
Senior Member
SuperSport
Joined: May 2008
Posts: 530
From: Central Fl.
Rich/lean is controlled by the jetting of the carbs and the flow, once past the petcock, is controlled by the float needles in the bowls. The vacuum operated petcock is for convenience only. Back in the day, the petcocks were operated manually and even if you forgot to turn them to off, the float needles would stop all fuel flow as the level rose to the top in the float bowl. (Assuming that there was no fouling of the needle or seat.)
So, no, the petcock doesn't affect the richness of the carbs.
So, no, the petcock doesn't affect the richness of the carbs.
07-21-2008 | 03:00 PM
#3
Senior Member
SuperBike
Joined: Feb 2007
Posts: 1,051
From: Portland, Oregon
in a perfect world the needle & seat that the float operates would control the fuel level in the bowl... but a little wear will / can cause the bowl to fill with fuel. since the tank is higher than the carbs the gas can drain down into the cylinder.
tim
tim
07-29-2008 | 09:39 PM
#4
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World Champion
Joined: Dec 2004
Posts: 105,287
From: Fulton, MO
These petcocks stick after a while. I dunno why. Mine does the same thing. Now I just treat it like a manual and whenever I remove the tank I use the 8mm wrench on it, otherwise fuel will be everywhere!
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