Leaking carbs and weird fuel petcock

[Cgreen]

Guys,

Got a weird deal going here, restoring my dads 97 Valk. It had been sitting since 2019 when he passed.
So I have Pull the carbs rebuild them new jets all the Needles Valves float valves clean them real good put them back together bike was running fine. Then I started having a leak on the fuel tea on both sides so I pulled the carburetors back down took them apart and replaced the orings on the tees and on the vent tubes. Put it all back together again, hooked up the fuel to it, checked it out again no leaks from there so I’m thinking it’s good. Go to crank it up, crank it up, it’s running well, then I remembered that I had not turned on the fuel petcock which I have replaced with one I bought off eBay. Not having filled it up all the way with fuel, I set it to reserve, soon as I did, fuel starts running out of the left bank vent tube, so I turned it back to off, the rpms which were coming up, went back to idle, and fuel stopped running out the vent tube. So I switched it to the on position, and fuel starts running out the right bank vent tube and rpm started ramping up, so I turned it back to off, it stops running out of the vent, and the rpm starts coming back down to idle. I have no clue what could be making this happen? It was not happening before I took the carbs apart and changed the orings on the inlet tees. I replaced the petcock out cause y’all got me scared of hydrolock situation, so I thought I’d head that off at the pass with a new petcock.
  I’ve been through the carbs new everything except floats, and initially after the carb cleanup there was no problem with fuel running out of the vent tubes when I set the petcock to ON or Reserve??
Just can’t see a Scenario where this would happen?? Unless this petcock is a pos? Lost in Texas

[Willow]

If it's been setting for four years or more the rubber has dried out.  It's not unusual in that state for the lines to leak.  The reason they only leaked when fuel was flowing (on or reserve) is that otherwise fuel was being burned from the carb bowls.

After enough fuel has flowed (and leaked) through the lines they should moisten and swell causing the leaking to end. 

No problem with the petcock was indicated.

[hubcapsc]

If I had an ebay petcock and also had a gas leak problem, I'd
get a new OEM petcock, or a high quality Pingel-style
replacement petcock.

-Mike

[WintrSol]

By 'vents', did you mean overflow vents? If so, at least one float is stuck open, causing that carb to overflow. If this is what you meant, then fuel treated with a strong dose of Seafoam or Berryman's B12 may unstick them, and clean out any other dried fuel stuck in there. Of course, YMMV.

BTW, unless you damaged them, jets don't need replacing, since gasoline doesn't wear them. Only hard parts that wear could be the needle jets, as the needles could wiggle around in there. Or if you changed something in the air-to-exhaust path that requires a change in size.

[Mooskee]

Fuel running out the top tee, the air rail vent lines is because a float bowl needle valve did not seal. If you didn't replace them the springs are likely weak and the rubber rips are worn. If you did replace them with ones from All Balls or a cheaper Chinese rebuild kit it is because the float bowl needles  in those kits are inferior. Use Honda float bowl needles or K&L 18-8955 needles. If fuel ran out of the left and right side air tee then you have at least one bad bowl valve on each side.  Be very cautious of hydrolock.

Replacing jets after carbs have sat for years with fuel in them is actually a good idea because they are generally plugged with goo from the fuel.

I have no idea how many carb sets I have rebuilt, but certainly more than most. I have seen many many worn out float bowl needles and plugged jets.

I have also seen on the forum here some stories of lesser expensive petcocks from eBay failing in a short time. I highly recommend getting a Honda one, or replacing with a quality one such as a Pingel.

Respectfully,
Dave
Valkyrie Carbs and Custom

[WintrSol]

Cleaning plugged jets can often be done with a good solvent and an ultrasonic cleaner. Depends on how much time you will let it take. Using aftermarket jets is a crap shoot, as they often don't consistently meet the size specs. All in which side you look in from.

[Mooskee]

Jets R Us carries Keihin jets.

[indybobm]

What kind of shape is the gas tank in? Rusty? Have sediment in it? its is possible that debris from the gas tank is holding on of the float valves open.

[idaida98]

Bought one off ebay 3 yrs ago.The thing leaked could not shut it off  contacted seller no reply.

[Cgreen]

Figured it out, I didn’t break the carbs apart when I cleaned them up and it looked like some bug casements or something like that all down in the fuel joints. I have them completely disassembled now and plan to take them and have them ultra soniced, buying all new Honda floats and needle valves. I already cleaned and put CREAM in the tank. But I plan on adding an inline filter between the petcock and the middle fuel tee.
I cant get the new petcock to mess up again, when off, nothing comes out now, put it on ON or Reserve it does not run out until I apply suction to to petcock, now it runs fine?? I think it was just one of those days where everything you touch turns to crap!! My mower float stuck that same day and filled the crankcase with gas when I went to eat lunch, smoked like holy hell when I started it back up!! Days like that happen to me quite frequently!!! Lol

Main thing now is getting the carbs perfect, I like to do my own wrenching, even if I have a day like that now and then. When the petcock kept flowing, it showed me which carbs are leaking by, 4 and 5 intakes filled up with fuel, luckily I was trying to figure out why the fuel was coming out the vent tubes, so I never tried to start it again, I just started pulling the intakes to remove the carbs, and found both 4 and 5 were full of fuel, so I dodged a bullet there!!

Thanks for all the help

[hubcapsc]

Valkyries tend to hate added in-line gas filters...

-Mike