Re: Weekend Puzzler

Posted by Joel Z on August 28, 1998 at 22:02:43

In Reply to: Weekend Puzzler
posted by Kevin Daly on August 28, 1998 at 11:44:45

: Hi Folks,
: Here's one to ponder over the weekend!As we all know by now my Zenith's viton tipped float valve weeps.Yeah I know "BIG DEAL they all do!"You're right!, even I'm sick of hearing about it!With that in mind, here's the Weekend Puzzler.
: I've replaced the gas tank pet cock and am certain that once closed, the gas is stopped at the tank.I have gotten into the habit of turning off the gas and letting the engine run until it stalls from fuel starvation.The following morning the bottom area near the weep hole has gas around it, but it hasn't apparently dripped.By now you're saying "Your taking up my time for a wet spot?"Let me finish!
: I feel that by running it dry with the tank shut off the carb float drops and opens the fuel valve.Then slowly over 8 or so hours the fuel left in the line from the sediment bowl to the carb fills the carb up slowly and over that time raises the float to shut the valve again (Ever so Gently).My theory is that the process of filling slowly, shuts the valve but not tightly.This condition then allows the small remaining volume of fuel in that line to continue filling the carb and weep out the jets just enough for a wet spot.
: The carb is properly rebuilt and adjusted. The fuel height internally has been checked and is indeed 5/8" below the parting line of upper and lower castings. It can't be wrong, You guys told me how to fix it!
: Pay attention here comes the puzzler.
: Under normal operation the valve opens and closes as the level of fuel rises and falls which is a result of mixture, driving speed... This process of up and down,open and close happens relatively quickly within the carburetor under these conditions.As the level rises quickly the float valve closes quickly and would probably "seat harder" than the run it dry scenario and would probably be less apt to let fuel pass by overnight causing the offending "Wet Spot"
: Should I run it dry or just shut her down and turn off the tank?
:
: What Do You Think? --- (Said slowly with a mysterious inquisitive tone!Picture Jack Palance!)
: Who Knows,This just may work out to be a weekly column
: Have a great weekend!We'll see what happened next Thursday when I return from vacation.Don't talk about me when I'm gone! I have spies everywhere!
: Regards,
: Kevin Daly
: PS I know it's hokey, but no more than that guy who wanted to know just what the salesman is thinking on the cover of Bratton's 1998 catalog! Don't you think?

Kevin, I like the Jack Palance thing, made me chuckle. I'm not sure that there would be enough gas left in the sediment bowl bowl to refill the line and the bowl to the point that they are over full. I'm not convinced that you gas is really stopped at the tank overnight. How about this, as long as we are having you take apart and put together your entire fuel system several times, before anything else disconnect the fuel line from the carb and see if the line is full. If it is then fuel is getting by the shutoff, not unusual. If it isn't then your carb is somehow creating fuel by itself and you may never need to buy gas again.
Even better, try not turning off the gas to starve the engine and see if you get the same weeping. If you don't then you really don't need to take apart your fuel system 37 times, except for fun on a slow weekend.
Finally, if you can't solve the great wet spot mystery, accept the fact that it will be there and be happy that it isn't a drip, a trickle, or God forbid a full blow running leak. Hope you had a great vacation, and remember that a Model A with a little problem is better than any other car running perfectly.
Joel Zinnecker
Lincoln, NE