Boat Not Idling

[gallion_t]

A few weeks ago a bought a 2002 Bayliner with the 3.0L Mercruiser. The first few times I took it out it ran great with no issues, but I went to take it out on Sunday afternoon and I couldn't get it to idle. If I put it in neutral and gave it a little throttle it would fire right up and run smooth, but as soon as I back it down to idle it would die.

My first thought is that there is something in the idle jet on the carb. The boat had been serviced every year, but not actually licenced and used since 2012. When I got it there was still a few gallons of gas in it which makes me think it might have been old and managed to gather some crap in it. I am going start by spraying some carb cleaner in it, checking the fuel filter, and adding some fuel additive.

Is there anything else I should be looking at to start?

Thanks,

Travis

[MADMAX]

Drain the gas and go fill it at CENEX with non-ethanol gas, change the fuel water seperator and rebuild the carb

[CP]

Sitting that long I’m sure the gas has evaporated off leaving varnish behind in the jets and orifices.  You can try the carb cleaner and running an additive like Sea Foam through it.  If that doesn’t work the only way to clean it out is disassemble the carb and clean everything.

[Stein]

If it were me, I would pull the carb, ultrasonic clean it and rebuild it while I had it out and apart.  I would also check the fuel lines and filter and likely replace both on a boat that age unless they are pristine and look like they were recently done.

[Happy Gilmore]

Flush tank, lines, replace filter. If it does the same with new ethanol free fuel then pull carb. You need to do the tank and lines anyways. Start there first. Make sure fuel lines aren't mushy too. If you see any signs of black stringy looking stuff in the filter its the lines breaking down and they must be replaced.

[gallion_t]

Thanks guys. I tried spraying the carb cleaner, adding the fuel additive, and swapping the filter with no luck. I was trying to avoid having to pull and rebuild the carb, but It looks like that's where I'm at. Looks like there is two different options for the rebuild kit so I'll have to take a look and see which one I have.

Thanks for the advice guys. I was hoping there was a simple fix.

[Happy Gilmore]

Did you try pulling the line off and using a pony tank with fresh fuel? Adding fuel dryer to stale gas isn't going to help anything.

[Wazntme]

Welcome to your new part time job as a boat owner!

[gallion_t]

No, I haven't pulled the lines off and tried using a fresh gas. When I got the boat there was maybe 5 gallons of gas in it and now the rest is fresh 17-18 are fresh. I am going to try to pick up a rebuild kit this weekend and do that.

[Miles]

Welcome to your new part time job as a boat owner!

Lol.   They say the two best days are ________.   I'm sure someone can fill in the blank.


Plenty of advice already given.

[Happy Gilmore]

No, I haven't pulled the lines off and tried using a fresh gas. When I got the boat there was maybe 5 gallons of gas in it and now the rest is fresh 17-18 are fresh. I am going to try to pick up a rebuild kit this weekend and do that.

Well, adding food gas to gas with water has a very high problem potential. It's why boat shops are full this time of year. Drain ALL the fuel, purge the lines, replace the filter then, go deeper.