Engine acting wierd after winter storage, any suggestions?

[taitrt]

I have a Mercruiser 3.0L and I have been having some issues with it ever since it started getting cold. I live in FL and the boat was not winterized, but I had a work light in the engine compartment any time the weather got below 32*, which was only for about a day this year (which is still much longer than normal).

I went to start up the engine after the weather had warmed up a bit and it was acting a little funny. It started right up without a problem and ran for about 45 seconds at which time it just died without warning. I tried to start it back up and couldn't get it to run for longer than ~5 seconds. I let it sit for a day and tried again and the exact same thing happened, started right up and ran for around 30-40 seconds and then died.

Skip forward a month, I waited for it to get warm (60s-70s) and tried to start it again, exact same thing happened, it ran for 30-40 seconds and died, then failed to run for longer than 5 seconds.

I'm hoping it's just bad gas or water in the gas as I didn't put any conditioner in the gas tank before I stored it for winter. Is there anything short of siphoning all the gas out that I could do to figure out if it's the gas or something more serious?

[kyle f]

Definately sounds fuel related and if it is bad gas... well you will have to get it out of there.

What you could do is dribble some gas as it runin the the carb and seeif it keeps running to confirm this.

Also, it could be a bad fuel pump, the filter could be clogged, or you may need a new water/fuel seperator canistor.

[Skywalker022]

I second kyle f. sounds like bad fuel. Do you smell gas real bad in the engine compartment when this happens?

[taitrt]

[roomservice]

is it hard to start. by that i mean when you crank it does it sound like the starter is having to work extra hard to turn it over? if so , dont crank it no mo, could be water in the cylinder. if not , then it prob is bad fuel. not really bad, just old. fuel goes bad faster with the higher alcohol content in fuel now, a lot of the business end evaporates faster. and the fuel that you had last put in had the mix intended for summer weather not the surprise chilly winter that fla had.

if some fuel treatment does not solve the problem, drain it (dispose of properly of course) and put in some new good stuff.

good luck

[kartman]

as a mechanic, i would drain and flush the fuel system and start with fresh fuel.

[pet575]

As a non-mechanic, I agree that fuel is the place to start. I'd start with the water separator and/or any other in-line filters.

[Skywalker022]

roomservice, What do you mean (dispose of properly of course) I thought you put it in a jug, light it on fire, and then shoot it with some sort of high power firearm!

[roomservice]

[BrentC5Z]

Fuel condensated & water made it to the seperator. After time passes the water settles to the bottom of the seperator. When running, it's mixed with the fuel and the engine shuts down.

Just my crystal ball guess


Or maybe 4.5 years of working on watercraft.

Drain it all. You'll be better off. I installed a valve in the bottom of a large fuel can & recovered peoples fuel in it. After a few hours, we could drain the water from the bottom. One of the mechanics would run it in his old van......down by the river!!!

[Hollywood]

How about we determine if it is bad gas before draining it and refilling up the tank?

Take the fuel pump supply line off and attach a new hose to a fresh can of gas.

[pet575]

taitrt, how old is the gas? Is your tank completely full? If it is only like 1/2 full, it might be easiest to get a can of Sea Foam in there, then fill it the rest of the way with fresh gas.

[taitrt]

[Hollywood]

Unfotunately it still won't tell you if you have fuel problems from the pump to the cylinders though. Are you carbureted or injected? If you aren't gummed up there hopefully it'll run off the gas can. Keep everything well ventilated!

[JUST-IN-TIME]

those 3.0L TKS motors had some cold starting problems

if you post or email me the serial number i can email u the service bulletin

change fuel filters first and check cap and rotor and plugs

but the 30 second running is fuel related

[taitrt]

Update:

It finally got warm enough here in Fl to motivate me to work on my boat. I tried the boat out today just to see if it had magically fixed itself and surprise, it did not.

I went to autozone and got some seafoam. I took off the flame arrestor and dribbled seafoam into the carb and started it up. Sure enough it fired right up and I continued to dribble a little seafoam into the carb every 15-20 seconds and kept the boat running for about 10 minutes like this. I hoped that it had worked out whatever crap had accumulated so I decided to give it a little throttle. Almost immediately after giving it throttle the boat died and misted seafoam and gas out of the carb.

I am now about 99% sure it's just bad gas, but there's about a 1% chance it has a bad fuel delivery system. I looked around and can't seem to find a water/fuel separator to save my life, I was under the impression that they looked a little like an oil filter, but the only thing I can see connected to the fuel line is a little thing that looks sorta like a thermostat housing... is that the separator?

Here's my next question: I have no idea how to dispose of 15 gallons of gas. Would pumping the gas tank be something that a normal autoshop could do for me? or am I going to have to trailer my boat to the nearest marine repair shop (about 45 minutes away)?

Is there anything else you guys would suggest doing before I give up and send it to the shop?