all thumbs = gas mess
 

On our last "sail trip" (21 hours motoring, one hour sailing in 10 days), the A4 was unusually smelly. Not exhaust or gas smell, but kind of eye-stinging...sort of like a wood finishing product. Turned the boat upside down looking for some spilled product. Wondered if she could be running too rich, but fuel consumption was well under 1 gph at 1500 RPM. Choke good. Starts and runs great. Plugs a bit on the sooty side, but not extreme.

Our next trip is in a few weeks, so decided to install the Indigo PCV kit I had on our previous A4. (current A4 is a Moyer rebuild from 2015). Doing this to eliminate blow-by as a possible cause of the odor....?

As usual, taking the carb off was easy, but no matter how prepared I think I am, removing the fuel line ends up in a couple tablespoons of gas spilled. I have vowed to find a better way. Wondered if anyone runs the carb dry first, which led me to thinking about a second fuel shutoff valve just upstream of the carb. Otherwise, I will be running the engine quite a while to burn all the fuel in the Racor and polishing filters.

Any tips appreciated!

Marty, I had my second shut off valve on the fuel pressure gage. When ever I left the boat in the slip I ran the gas out, however weekending I did not. No messes when almost all of the gas is out of the carb bowl.

Dave Neptune :cool:

Marty,
Doesn't matter where the shutoff is - locate it for convenience. On my Tartan 30, the inlet to the primary Racor worked well.
Engine will run until the float bowl runs dry. You're not going to draw from the lines upstream of the float valve.

Oil absorb cloths will also adsorb gasoline. Pull the fuel line off with one in your hand or put one in place to catch the spill.

TRUE GRIT

When I setup the replacement electric fuel pump, I put a manual switch in its power line. The idea is I can switch off just the fuel pump with the motor running. With no power, it won't refill the carb bowl, and eventually run it dry.
Since the pump is higher than the tank, it should not have any siphon ability.

As others have said, putting a fuel shutoff valve in-line before the carb will minimize spillage.

Check out Neil's post #8 in this thread for a possible option.
(Hoping Neil doesn't mind) ;)

polishing filter
 

Thank you for the replies. Interesting there are a few different solutions.

I should have been more precise in my first post. The spillage is always from the polishing filter, not from the carb. It is lower than the gas tank. If I put a valve between the Racor and the polishing filter, can I run the polishing filter dry? Or will the electric fuel pump be unable to pull that gas out?

Thanks!

I plumbed the the polishing filter so I can leave it attached to engine compartment when I pull the fuel line with the carb leaving minimal fuel to leak when I remove the carb

I'm not clear on the relative positions of your pump, Racor and polishing filter. It's typical to have Racor→pump→polishing filter→carb but from your last post I'm not sure where the pump resides.

Before I try to contribute to your question I'd like to be sure.

tank→racor→pump→polishing filter→carb
 

Yes, that's the sequence. Again I was imprecise: I am contemplating putting a valve between the Racor and the electric pump. Would that run the polishing filter dry?

Thanks all.

My guess is it won't result in a dry polishing filter but maybe worth a try anyway. I think the best position for a valve to achieve your goal is between the polishing filter and the carburetor. It seals off the fuel line right where you're opening it.

Marty, I agree it won't result in a dry polishing filter, but maybe a soggy one that is no longer saturated and dripping fuel. I tend to pull the outlet of the polish and let it drip into a container so I only have the pressure gauge/carb after it..it does drip a few tablespoons. My polish filter is also for sure the lowest spot.

Since my fuel tank shut off is inconvenient to reach, I added one at the inlet of the Racor...my plumbing is: tank --> always open valve --> hose under the cabin sole --> easy to reach valve --> Racor -->mech pump -->polish --> pressure gauge --> carb.

I forgot to open the "easy one" once and the engine ran dutifully for 20-ish minutes while we prepped for departure and until I backed out of the marina slip just out of boat hook reach and promptly died. :rolleyes:

It sounds like you are trying to burn out the fuel in the polish filter...if you put it in front of the electric fuel pump maybe but I dunno if that is bad on the pump or not..:confused: