86 V20 Cuddy 3.7L shakedown run in Norfolk

[Destroyer]

Yup. If I was a betting man I'd bet that you have a load of bad fuel/dirty tank/etc. Sounds like you need to open the inspection hatch on the tank, pump out whatever crud that's in there and clean the tank and lines.

Oh, and do yourself a huge favor and buy a fuel/water filter/separator. That should be the absolute last thing your fuel goes thru before it is in the short line to your engine's carb or fuel rail. This way you know that your fuel is clean. Period. (Get one of the ones with the clear plastic bowl on the bottom that you can empty the water out of). Moeller makes a good one, as does Racor, Seasense (Walmart) and several others. Cheapest $60 (about) piece of mind you can buy.

http://www.ebay.com/itm/Moeller-Wate...JXkSxQ&vxp=mtr

http://www.ebay.com/itm/Moeller-Clea...5X0BTL&vxp=mtr

[garbubba]

Testify about the fuel water separator. I had similar problems with my 20 when I first got it. Instead of cleaning out the tank, I just put an in-line filter where I could get to it easy (right in side the battery compartment) and carried spares including one that I could clean & reuse. I had to change that thing offshore a few times, cussed it out a few times too, but it did the trick.

[THEFERMANATOR]

EVERY boat should have a spin on fuel water seperator mounted just before the engine where it is easily accesible. Can't tell you how many times I've had to stop at sea to swap one out. But its better than plugging a carb up and burning your engine down. Beings this is an I/O, check your fuel pump. Most I/O pumps I've encountered have there filters on the intake side so the only filter to catch debris coming out of the pump is the filtet in the carbs inlet. If you have filters before the pump not plugging but are still getti,g debris into your carb, then the only place it can come from is the pump itself, and is normally a sign that its diaphram is coming apart(when this happens, they start dumping gas either into your engine, out the vent hose, or worse, into your bildge.

[RWilson2526]

Good advice from Destroyer but being that you have an I/O and will have to mount fuel filter under the engine hatch I belive USCG does not allow the plastic bowls on fuel filters for that installation.

[1966Mustang]

Took a look into the tank last night - it's about full of fuel - 50+ Gallons.

What is currently set up in there is:
Tank -- Napa F/W separator -- FuelPump Filter -- Carb Filter.

I pulled the carb filter - nothing to mention in there.

Pulled the fuel pump filter - nothing there.

Water separator didn't look like it had water in the fuel

Took a fuel sample from down the bottom of the tank into a glass jar and let it sit overnight... Nothing separated out. Not finding an obvious smoking gun yet.

I do have a napa fuel/water separator - looks like a regular filter, no drain hole. I am going to replace this with one with a drain. Parker/Racor makes one that fits the OEM mercury mount about $50.

In addition to that I am going to get small aux tank to hook up to with known good gas to do a test run. If it runs all right on there, I'll know the fuel in the tank is the issue for sure. This seems like the easiest way to troubleshoot.

If it displays it's issues again, then I'll know I need to dig deeper... plugs, wires (which are new, but wrong style end), take a look at the dizzy.

[chart]

if your not finding anything in your fuel next time it starts sputtering try popping your gas cap its a long shot but maybe a partially clogged vent?

[Destroyer]

Originally Posted by chart

if your not finding anything in your fuel next time it starts sputtering try popping your gas cap its a long shot but maybe a partially clogged vent?

Chart, that's a damn good suggestion.

Originally Posted by RWilson2526

Good advice from Destroyer but being that you have an I/O and will have to mount fuel filter under the engine hatch I belive USCG does not allow the plastic bowls on fuel filters for that installation.

Rob, I wasn't aware of that. Good to know. Thanks