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I feel obliged to post John's definitive response as to how to replumb post octo:
Thanks all.
James,
It's rather easy actually. Turn the fuel off, and remove the tank. Tilt the tank forward and turn the petcocks to the prime position, and tilt the tank back to level and determine which nipple on the petcock the fuel is pouring from. Cap that port off with a 1/4 inch cap. Do this to both petcocks. You won't be using it at all. The petcocks will prime the carbs just by turning them on. There are two ways of plumbing the fuel lines. The first method is the easiest, but you'll need to use both petcocks. Just run a length of 1/4 inch fuel line from the right side petcock to the#1-2 carbs, and from the left petcock to #3-4 carbs. Run the lines over the top of the air inlet boots. The next way is a little different but I prefer it. Attach a short piece of fuel line, 2-3 inches, to each fuel inlet T fitting in the carbs.
We'll call this one the inlet line. Then to the open nipples of the petcocks, run a piece of fuel line from one petcock to the other, so you are connecting them to each other. We will call this the crossover line. Tailor this line so there are no kinks, and it lays smoothly over the intake boots when the tank is installed. Now, where the short pieces of fuel lines attached to the carbs intersects the crossover line, cut the crossover line there and just insert a T or a Y fitting and attach the crossover line to the inlet line and you are done. Be sure to tailor the inlet line so that there are no kinks. This way you can use just one petcock to feed all carbs with out any starvation issues. Make sure you have no kinks and cut the line so that eveything is nice and neat. When it is time to hit reserve, you can turn on the unused petcock to use the remaining fuel that is in that side of the tank. When that runs down then you can switch to reserve when you need to. This method will allow the fuel to balance out in the tank when both petcocks are opened. This is the setup that I use on my bike, and I have no fuel starvation issues untill I hit 100 mph or faster. Then I just open the other petcock if I want to go that fast. Now use a 3/16 vacuum plug and cap off the vacuum port on the carb boot that used to supply the vacuum to the octopus. Put the tank back on and attach the lines to the pet cocks. Open one petcock and wait a few seconds for the bowls to prime themselves, and check for leaks. You will need to remember to turn the fuel on and off eveytime it sets for any lenght of time. This will insure that no fuel will leak past the float needles and get into the oil.
I hope I made this easy enough to understand. Once you get it all plumbed up, you will see just how easy it is to do.
Good luck with it, and if I can be any further help, you know where to find me.
John
Thanks all.
James,
It's rather easy actually. Turn the fuel off, and remove the tank. Tilt the tank forward and turn the petcocks to the prime position, and tilt the tank back to level and determine which nipple on the petcock the fuel is pouring from. Cap that port off with a 1/4 inch cap. Do this to both petcocks. You won't be using it at all. The petcocks will prime the carbs just by turning them on. There are two ways of plumbing the fuel lines. The first method is the easiest, but you'll need to use both petcocks. Just run a length of 1/4 inch fuel line from the right side petcock to the#1-2 carbs, and from the left petcock to #3-4 carbs. Run the lines over the top of the air inlet boots. The next way is a little different but I prefer it. Attach a short piece of fuel line, 2-3 inches, to each fuel inlet T fitting in the carbs.
We'll call this one the inlet line. Then to the open nipples of the petcocks, run a piece of fuel line from one petcock to the other, so you are connecting them to each other. We will call this the crossover line. Tailor this line so there are no kinks, and it lays smoothly over the intake boots when the tank is installed. Now, where the short pieces of fuel lines attached to the carbs intersects the crossover line, cut the crossover line there and just insert a T or a Y fitting and attach the crossover line to the inlet line and you are done. Be sure to tailor the inlet line so that there are no kinks. This way you can use just one petcock to feed all carbs with out any starvation issues. Make sure you have no kinks and cut the line so that eveything is nice and neat. When it is time to hit reserve, you can turn on the unused petcock to use the remaining fuel that is in that side of the tank. When that runs down then you can switch to reserve when you need to. This method will allow the fuel to balance out in the tank when both petcocks are opened. This is the setup that I use on my bike, and I have no fuel starvation issues untill I hit 100 mph or faster. Then I just open the other petcock if I want to go that fast. Now use a 3/16 vacuum plug and cap off the vacuum port on the carb boot that used to supply the vacuum to the octopus. Put the tank back on and attach the lines to the pet cocks. Open one petcock and wait a few seconds for the bowls to prime themselves, and check for leaks. You will need to remember to turn the fuel on and off eveytime it sets for any lenght of time. This will insure that no fuel will leak past the float needles and get into the oil.
I hope I made this easy enough to understand. Once you get it all plumbed up, you will see just how easy it is to do.
Good luck with it, and if I can be any further help, you know where to find me.
John
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