I gave my fuel system just too much love!

[BonS]

Everything was okay until I improved it! While I was replacing my low speed jets I made a few "upgrades". I replaced the intake o-rings, vacuum lines and plugs. I also added an electric gas valve, filter and quick disconnect (with fuel line loop). I have a stock petcock. At first everything seemed to be just fine; starting, running, power all fine. However, after letting the bike sit for a few days I restarted it and some of the cylinders weren't firing. The exhaust pipes of the suspect cylinders (1,3) were cold. When this first happened I first checked for spark and everything was okay. I then cracked the drains on each carb to check for fuel. Before I could complete the trouble shooting I restarted the bike and it began to run normally. The next day I did a 100 mile charity run without any problems whatsoever.

Well the problem came back. The bike sat for a few days and when I started it to go to work I recognized the same problem was back. It started but was running very flat. Soon it died and wouldn't restart.

I separated the quick-disconnect and the vacuum line to the petcock; pulled a vacuum with my mouth and fuel flowed very well. The vacuum line stuck to my tongue and held it there with no vacuum leakage so I'm confident the petcock is working pretty well (isn't that how everybody does it?). The flow stopped just as soon as I released the vacuum.

Anyway,  I decided to simplify things a bit. I installed a (non-vac) Pingle petcock, removed the quick disconnect and associated fuel loop. I capped off the #6 vacuum port and the bike started up right away. Problem? What problem. My current setup is Pingle-to-filter-to-electric valve-to-carbs.

I don't have any idea what was caused all this but I do know that fuel wasn't flowing to the carburetors. I post this here so that it might help someone that might go down this same path. Anyone else tried my original setup (stock petcock-to-fuel loop-to-quick disconnect-to-filter-to-electric valve-to-carbs) and succeeded?

[Momz]

 Your not running a Car tire are you? 

[gregc]

  If 2 carb bowls were empty (dry) then it is not a petcock problem.  Sounds like something is leaking or draining the bowls. Unless you are shutting the valve off to stop the motor by running it out of fuel.

[Ricky-D]

No!! That's not even remotely a possibility.  Theoretically the petcock could stop five of the carburetors from getting gas.  The gas flows according to gravity and the "path of least resistance"  The carburetors farthest away will always be at the bottom of the pecking order when it comes to gas allowance. Like for instance the #! and #3 carburetors.

[John U.]

BonS, when you replaced your slow jets did you reset your pilot screws? I found on both my Valks that 38 slow jets and 1 1/2 turns out on the pilot screws would clog up from methanol just about as fast as 35 slows with 2 1/4 turns out. I reset the pilots to 1 3/4 out due to the bikes running lean and the clogging has improved. A dose of Seafoam or Techron (or just running the bike in your case) would have fixed the trouble, at least until next time.

[gregc]

How do you figure the petcock will stop only 5 of the 6 carbs ?  The fuel line is the same for all carbs, and the line will flow more then the carbs can use.  You lost me on that one.

[BonS]

BonS, when you replaced your slow jets did you reset your pilot screws? I found on both my Valks that 38 slow jets and 1 1/2 turns out on the pilot screws would clog up from methanol just about as fast as 35 slows with 2 1/4 turns out. I reset the pilots to 1 3/4 out due to the bikes running lean and the clogging has improved. A dose of Seafoam or Techron (or just running the bike in your case) would have fixed the trouble, at least until next time.

No I haven't reset my pilot screws but from what I've learned on this forum I will asap. I tried cleaning up my slow jets with Seafoam but it was just too bad or I wasn't patient enough. I was tired of the 35's lean running that would let the engine sometimes die when pulling away from idle and long choking required until the engine was warm. It now smells a bit rich and doing as you say and adjusting the pilot screws would clean this up.

[BonS]

  If 2 carb bowls were empty (dry) then it is not a petcock problem.  Sounds like something is leaking or draining the bowls. Unless you are shutting the valve off to stop the motor by running it out of fuel.

I will say that there isn't any sign of leakage from the carbs or drain lines or any smell of fuel in the garage and I'm not stopping the motor by running it out of fuel. The bike only sat for 2-3 days before this problem would manifest itself.

[Kingbee]

How full is your tank?

I had the same problem when I put in the fuel line loop, electric fuel valve and metal fuel filter.  Bike wouldn't get fuel once it got much lower than half a tank, not even on reserve.  Removing the fuel filter solved the problem for me.

[BonS]

How full is your tank?

I had the same problem when I put in the fuel line loop, electric fuel valve and metal fuel filter.  Bike wouldn't get fuel once it got much lower than half a tank, not even on reserve.  Removing the fuel filter solved the problem for me.

I think you're onto something!  The first time this happened I was about to go and get some gas for the next days ride. Second time, same condition; low fuel.

I put in the fuel filter because I had installed the quick disconnect and was concerned with crud entering there when disconnected. By removing the fuel loop and the greater flow area of the Pingle it seems to have corrected the problem of poor fuel flow as my tank is still really low on fuel.

By the way, with the Pingle it's much easier to simply pull off the fuel line (no vac line)  at the petcock as there's much more room for fingers and tools now.

[BonS]

Your not running a Car tire are you? 

It may not sound like it but I do know when to quit!