fuel tap position '84 petcock?

[robbygixxer]

hello all, prob a stupid question this but im fairly new to fj's, iv an 84 fj1100 and i notice the fuel tap has to operating positions, pointing down and to the side, my question is what is it point at?!! im assuming there a prime and a on..But what one is what?
thanks

[FJ111200]

There's a little arrow pointing away from the centre on the tap lever and there's two positions marked ON and PRI on the housing.
When the arrow points to ON, that's for the vacuum tap, when it points to PRI that's for priming the carbs to fill with petrol after a rebuild. It can run on PRI.
So, pointing down is ON and to the side is PRI.
Hope that wasn't to long winded.

[robbygixxer]

yep cheers, theres no markings on the housing so without removing the tank/pipe there was no way of knowing, ta very much

[bigbore2]

On the 84 1100 petcock there are two positions. one positionis labeled ON and one labeled as PRI. Is PRI some kind of code only certain people are priviledged in knowing or what?  I just bought this bike and only ran it in the on position before I started taking everthing apart to go thru.    AND THEN I read the post a couple down from mine.

[bigbore2]

So there is no way to turn off the gas and run engine a little to drain the gas out of the tubing so I can take off the tank without having to clamp off the tubing?

[Pat Conlon]

On the 84 1100 petcock there are two positions. one positionis labeled ON and one labeled as PRI. Is PRI some kind of code only certain people are priviledged in knowing or what?

PRI is short for Prime, as in prime your carbs. Also used to drain your tank with the engine not running.
Do not leave the petcock on prime.
The petcock will be open all the time. If you have *any* leakage from your carb's float needles, you will wake up one morning with 4 gallons of gasoline on your garage floor, and the remaining gallon of gas will be in your crankcase.
Not an ideal situation for promoting your morning serenity.

So there is no way to turn off the gas and run engine a little to drain the gas out of the tubing so I can take off the tank without having to clamp off the tubing?

Sure there is. Disconnect the vacuum line from the petcock (and plug the open vacuum line) and the petcock will remain closed (no vacuum) while the engine runs the gas out of the carbs.

[bigbore2]

Pat- thanx.  Just so I can be absolutely sure, so I can plug the vacuum line port and remove tank with gas in it and set it aside for a day or a week, etc. without worrying about tank dumping fuel?  As long as vacuum port is capped no gas can come out of tank?

[SlowOldGuy]

As long as no vacuum is applied to the vacuum port on the petcock, fuel "should not" flow out.  Unfortunately, the petcocks are known to "seep" fuel even though there is no vacuum on them. 

Be safe and attach a hose to the petcock fuel output port and tie it off above the tank height.  You'll probably notice some fuel in the hose after only a few hours.

DavidR.

[Pat Conlon]

Pat- thanx.  Just so I can be absolutely sure, so I can plug the vacuum line port and remove tank with gas in it and set it aside for a day or a week, etc. without worrying about tank dumping fuel?  As long as vacuum port is capped no gas can come out of tank?

No, what I meant was to pull the vacuum hose off the petcock and plug the vacuum hose, so when you start and run your engine (to run your carbs dry) you don't have a open vacuum line running to the #1 cylinder which will lean out the fuel/air mixture.
You do not need to plug the vacuum nipple on the petcock, no gas should come out of that.

+1 to what David said, even in the closed position (ON position with no Vacuum) the petcock will weep a tiny bit of gas. If if weeps more a a small bit, you need to overhaul and service your petcock .
See the Files section on how to do this: http://www.fjowners.com/index.php?topic=2264.0
New Yamaha oem petcocks are still available to purchase $102 from Powersports: http://www.powersportsplus.com/parts/search/Yamaha/Motorcycle/1984/FJ1100L/FUEL+TANK/parts.html

So if you are going to store your tank off your bike, and you have gas inside your tank, be safe and plug the gas nipple on the petcock. Also, while I'm on the subject of petcocks, safety wire your petcock asap:
http://www.fjowners.com/index.php?topic=3265.0

[edit] More than you wanted to know, eh?

[bigbore2]

Nope, too much info is OK.  I found out yesterday at the motorcycle salvage yard how the shut-off works on these petcocks. The on-off is vacuum activated and has a spring/seat valve arrangement.  Either turning over the engine with the start button or with the engine running, vacuum is made and opens the valve to ON. No vacuum and the seat closes via spring pressure and no fuel flows.  Some of that has already been covered but I needed to get in my 2 cents worth.