Petcock problems??

I think I may have a problem with my petcock. It seems like no fuel will come out when it is on the ON position. I thought the vac hose was blocked but I replaced that and still nothing. Anyone heard of this happening?

 

Not a lot of detail in your question.

Fuel should only flow in the "ON" position when there is vacuum on the line. Are you saying no fuel flows with the engine running ant the valve at the "ON" position?

How about on "PRI". If fuel isn't flowing when set to "PRI" look for clogged pick up screen or..... insufficient fuel in tank.

How about "RES". Does fuel flow on "RES" with vacuum to the valve?

 

OK, I'll repeat it in English this time. Sorry, I was a bit rushed before...
Basically, with the Petcock in ON, the bike will run for a while and then stall, the only way to get it started again is to put it in PRI.
I just took the hoses off and fuel does come out when I crank the engine over with it in ON, but not as much as if I put it in PRI, RES is the same as ON.

Background:
The bike has been unregistered for about 4 or 5 years and I;m about to get it registered again,. It has sat forthe last 6 months with the fuel tank taken off and in this time something made a nest of some sort in the vac line so I replaced that but its still happening

 

Take the Petcock out of the tank and clean the screen with Carb Cleaner and a toothbrush.

Open the front and take-out the guts of the Petcock and spray all the holes nice and clean.

Run a piece of weed-whacker plastic line in the outlet and do a "Roto-Rooter" with it.

Make sure the wafer is on the dimples and replace it after wiping it down with some Armoral.

You MUST run an Inline Fuel Filter beyond the Petcock and before the Carbs.

If the Problem isn't the Petcock ....
You got some Carb Cleaning to do.

You'll have to Clean the Carbs and make sure that you Pull-out the Float Valves and spray the Beenie Screens clear of any foreign matter.

Because you have to go that far to get the problem solved ... Keep on going and Clean the whole rack up nice and clean.
That will get you up and running again!

 

the carbs have been cleaned recently, they were a bit of a mess (one of the jets wasn't actually screwed in and was rattling around in there).

Are there any surprises to look out for when pulling the petcock? Any gaskets to replace or spring loaded parts that might fly out never to be seen again?

 

Not really.

One major surprise is the screen tower missing and rattling around in the tank.

As for the petcock ... don't open the Vacuum Unit. Deal with the front end.

2 Screws
Faceplate
Spring washer
Control Knob with O-ring Seal
Wafer Seal and Flow Control.

Extract the Control Knob real slowly and save wear on the O-ring.

 

cool, I'll give it a go when I get a chance. In the meantime are there any problems with leaving it as it is and running it in the PRI posotion and changing it to ON when I turn it off?

 

Nope, just remember not to leave it on "PRI" when sitting. Also, you won't have a reserve so watch your fuel closely.

**EDIT**
If you don't have an inline filter do that first. No good can come from running dirt down into your float bowls.

 

Check the vacuum line to the petcock is actually vacuum line. Other line can collapse under vacuum and stop fuel flow.