Fuel Line Help

I just noticed these two caps on my new bike. Is the blue one supposed to be there and should I hook the pluged fuel line to the black one?

http://i80.photobucket.com/albums/j195/ ... imfuel.jpg

 

That is a DANGEROUS condition.

The Fuel Pectock is weeping.
The Vacuum Line is Plugged and the Petcock set to PRIME.
The PRIME setting will allow Fuel to Flow at all times.

You could Flood the Engine.
You could have gasoline overflow onto the garage floor.

Short Term Fix:
Install Aux Shut-off Valve -- Briggs @ Stratton Hdwe Store -- $11,00

Briggs & Stratton Valve -- Valve Installed on Bike:


Repair:
Order a New Fuel Petcock and Replace the Old one.
Hook-up the Vacuum Line and have a Fuel Valve that will shut-off when the Bike is not running.

Alternatively: Rebuild the Petcock with a Repair Kit. May not have satisfactory results.

 

I just realized that I accidentally left the petcock on prime.

 

Pull the Plug off the Vacuum Line.
Hook-up the Hose going to the Intake Manifold.
Test it like that.

The thing looks like its leaking though.
Get rid of the Speed Clamp and use a quality Hose Clamp.
Run it for a day or two and evaluate the situation.

If the Petcock is still leaking you'll have a decision to make.
New or Kit.

You get the New one in a box and just Install it.
Done.
You get the Kit in a Package and go on an adventure.
You do an intensive rehabilitation and repair with the outcome in question.
Might be fixed.
Might leak worse than before you put the Kit in it.

 

It's still not right.

The line that's plugged is the vacuum line to the petcock. Normally, it would be attached to the petcock and the vacuum nipple on the #3 carb manifold. Somebody unplugged and capped it for a reason; most likely a petcock problem of some sort.

When functioning correctly the system feeds fuel because the petcock receives a vacuum "signal" (via that line) to open the diaphragm-operated valve in the petcock. "ON" and "RES" are vacuum operated; "PRI" allows fuel to flow all the time. If the petcock is allowing fuel to flow in "ON" without the vacuum line being hooked up, then you DO have a petcock problem, most likely a holed diaphragm.

Your petcock is weeping fuel; that and the plugged vacuum line leads to a suspicion that somebody knew there was a petcock issue and that was their misinformed solution.

Rick was absolutely right in regard to the overall situation: You have a safety issue developing here, you need to investigate and fix it before you end up burning your bike or your garage down, or filling your crankcase with gas.

It's not just a case of having left it on PRI.

 

I had very little fuel in the tank but the crank case still smells like gas. I will change the oil and filter.

I will also change the petcock but i'm still confused about the vacume lines. The line is coming from the #3 carb. Do I hook that one up the the petcock and leave the other 3 capped? Why are the other three caped?

 

Each manifold has a vacuum port. They are used for synchronizing the carbs. One gets "tapped" to be the signal for the petcock, on the bigger XJs it's usually #3, on the 550s it's #2 (for who knows what reason.) The other three remain capped until it's time to sync the carbs.

The line to the petcock is supposed to "signal" the petcock to feed fuel when it's in ON or RES. If yours has been feeding fuel in ON without the vacuum line attached, it either has a problem or it has been modified by a PO. The PRI position is the only position that should allow fuel to flow without the vacuum line. Something ain't right.

Even if left on PRI, your crankcase should not fill up with gas unless you have a stuck or misadjusted float. Gas in the oil indicates a two-pronged problem-- petcock AND carbs/floats.

So yes, the vacuum line should be attached to the vacuum port on the petcock, but the bigger problem is that it shouldn't be working the way it is. You need to figure out what's going on before you have a calamity.

How the petcock works and what's inside it is covered here: http://xjbikes.com/Forums/viewtopic/t=25058.html At the very least you need to diagnose your petcock before you ruin the motor or worse. Install a lawn mower cut-off valve if you can't do it right away.

 

I went to the local yamaha dealer today too see what they had for the petcock. They said to install a banshee petcock w/o the vacuum port and cap the third cylinder. Will that work?

 

It ought to work if they say the Banshee petcock will fit. That also assumes that the Banshee petcock will need you to turn it on and off. Why not give Chacal a shout and get a rebuild kit for your existing unit and rebuild it??? Then you won't have to worry about remembering to turn it on and off. I, and not just a few other XJers, are in the area. Need a hand?

 

Yes. but Go to chacal. It comes with everything need to mount it up correctly, and even comes with a cap to cap off the 3rd carb port. I got the same petcock from him and absolutley worth every dime!

 

For now I'm just going to put a simple petcock on to get the bike going.

Robert: Thanks. I could use some help when I do rebiuld the stock one.