TOPIC:

Is that showing about 17mm? My hole spacing is 44mm (roughly 1 3/4 inches)

pa317 wrote: Is that showing about 17mm? My hole spacing is 44mm (roughly 1 3/4 inches)

No, not mm. That is showing 1.750 inches. Ed

Not everyone took shop classes.....

A little math

1 3/4 inches = 1.750 inches = 44 mm ( exactly 44,45 mm )

Ha, is it that obvious that I never took shop? Something that I don't understand is how the unrestricted fuel is causing the terrible idle & dying. The way I am thinking of this is a non-vacuum petcock allows fuel to flow freely. That's basically what is happening with mine, so why should it cause any performance issue? It seems like the only issue my faulty vacuum petcock would create is fuel dumping on the ground via overflow tubes when the ignition is off.

Your leaky petcock is a problem..... but its not your only one.

You need to take a few minutes to become familiar with the layout of your bike's petcock and carbs. Take a close look at the fuel line from the petcock, the vacuum line from the petcock, and where they each attach to the carbs.

Notice the fuel line runs to a “T” at the center of the carbs. From there fuel flows to each carb and goes through each carb’s float valve into the carb bowls. The float valves control the level of fuel into each carb bowl by shutting off fuel flow when the bowl is filled to the correct level. Fuel is then drawn from the bowls into the cylinders as needed.

Now look at the vacuum line. It does not connect to the center “T” or to any carb bowl or to any device such as a float valve that controls fuel flow. Instead, it is connected to the #2 carb up near the carb throat through which fuel flows to cylinder #2. If fuel flows through that vacuum line it flows directly into cylinder #2 without ever going through the carb body. That will cause cylinder #2 to receive too much fuel, and that will make that cylinder run poorly or not run at all.

The non-vacuum petcock does not have a vacuum line, it only has the fuel line that connects to the center “T”, so it is impossible for fuel to bypass the carb bodies and go directly into a cylinder. Ed

So it is correct thinking that although the petcock needs to be fixed, that isn't what is causing the poor idle. I keep looking for excuses not to tear the carbs apart and risk messing it all up

If fuel is going through the vacuum line it is also going into the engine and fouling the oil. Flooding carbs can do that too. Fix the petcock and go through the carbs. Once done sync them.
Steve

pa317 wrote: So it is correct thinking that although the petcock needs to be fixed, that isn't what is causing the poor idle....

Please READ the last reply I sent. Ed

Hi Ed,
Thank you for all the advice so far. After getting the Golan filter in the mail the other day I took a look at how it would fit on the bike. That's when I realized that I posted wrong information on here. Fuel is freely flowing from the fuel port, not vacuum. I went wrong by comparing my petcock to the diagram in my manual and saw the port on the left was vacuum, while the port more on the right side was fuel. In real life, matching up which ports were 5/16" clearly pointed out I was a knob and fuel was not flowing out of the vacuum port.
This past weekend I sat with the bike (gas tank off) and had the manual there to follow all the hoses to see where they connected to, and tried to understand how they function. That's where I got held up thinking that even a vacuum petcock doesn't manage the flow of fuel other than allowing it to be on/off.
Overall, I tried cleaning the carbs on a moped 15 years ago and caused more harm than good. That's why I'm trying to think through the entire issue list before doing any work. I also have a wife who tells me not to spend any more money on it, so that's why taking it to a pro is not a choice

For a guy who has never looked at a petcock closely, I made the error of looking at the port on the left and matching it with the left most in the diagram. Even the shapes seem to match better swapping the two. I'm guessing most people reading this are either shaking their head or calling me a dumba**

A correction to my earlier post: when I took the gas tank off, fuel was flowing out of the fuel port; not the vacuum port