Is This Possible?

[Coyote]

While changing the floats and resetting the float heights the other day, I noticed something odd. You might remember I had trouble getting the center cylinder to run.. Well when I removed the bowls, there was residual fuel in the left and right bowls, but the center was dry. Totally dry - like it never had any fuel in it.
Those familiar with the later 550's know the fuel feeds between the left and center carbs - then crosses over to the right from the center carb. How could I have fuel left and right and none in the center? In my mind, that's impossible. But it sure looked that way.
The motor is still apart. Waiting for son to come over and compress the rings while I drop the cylinders back on. I can do that job alone with the motor on the bench, but not in the frame.

[bill in okc]

You must have made the right call to readjust the float levels.

[Alan H]

After a run, the middle pot/carb area is warmer than the outside two, so the fuel evaporates more?
The carb will get heat from the crankcase/gearbox as well as the cylinder. More than the outer 2 perhaps.
I've noticed that the middle pot on my K takes a bit more 'starting' than the outer 2 after being stood more than a couple of days after a run, so may be similar to yours?
I usually fire up on the starter and it takes a few turns to pump the fuel through I suppose, so if the middle floatbowl is empty and the outers not quite empty, that would be logical (said Mr. Spock!)

[tz375]

eeze posseble fo sho.

If the needle valve is stuck or blocked on the center carb, fuel will flow over to the right carb and the center bowl will stay dry.

[yeadon_m]

When fussing in the past with float heights on my GT380, I've carefully removed carbs after a run to find exactly the same fuel level in each bowl. So IMO, if you had a dry centre bowl, you have some kind of problem.
Mike

[rngdng]

eeze posseble fo sho.

If the needle valve is stuck or blocked on the center carb, fuel will flow over to the right carb and the center bowl will stay dry.

Agreed. That's my bet.


Lane

[Suzukidave]

If the carbs are still off you could maybe do a bench test with the bowls off and use water instead of gas to see whats going on ?

[Coyote]

I'm surprised no one ever came up with Lexan bowls or even just a glass tube on the side. That would take all the guesswork out of it.

[rngdng]

I've actually seen lexan bowls before. They were sold for a time but I guess didn't go over well.


Lane

[tz375]

I have a couple of sets of Lectrons with clear float bowls.

[Suzukidave]

A google search pulled up quite a few posts on checking fuel level on assembled carbs by rigging up a small length of model fuel line to the carb drain and then up the side of the carb bowl . When the bowl is full you can check the inside level by the level in the fuel line next to the bowl .

[Coyote]

I've seen that method before. Easy enough to do, if and when you can ever find spigots to fit the drain hole threads. I have never seen anything even remotely close.

[Suzukidave]

Dont have one handy to check .. but would a main jet thread in ?