Ok sort of...

[J. Huber]

So my other convertible is a 2005 Bayliner 195. It has an I/O MerCruiser motor. 305 I think? Bought it new and all I know how to do is launch it, turn the key and have a lot of fun. Each Fall I have it winterized -- then spark it up in May or June. Always ran like a champ. Until now. The first and last two times I have gone out this year, the engine doesn't seem to want to idle very well. I can get it to start, and with some punchy effort, get it under throttle. Then it is fine. Lots of power, responsive, etc. However, when I then pull down to idle, it will stall. Kind of makes docking a challenge!

A few opinions have suggested that it may be fuel contamination (ie a bit of water got into the fuel). Feasible I guess. I store it indoors most of the winter but it did get rained on fairly hard in May after I pulled it out. It sits outside with a mediocre cover that has let water into the boat for sure.

I put a bottle of Lucas cleaner in yesterday before I went out -- after some spirited running to work it in, it did seem to idle for a little longer but then got lousy again. Came off the lake bummed out. Is a visit to the boat shop in order?

If it were my Pagoda, I'd be in there messing with something (ignition as well as fuel) but this is new territory and way above my pay grade. Thought I'd solicit some help from my trusty comrades before I go too far...

[Cees Klumper]

James - besides getting it winterized annually, do you have any regular maintenance done on it? Until recently I owned a boat with a 3 cylinder Volvo penta marine diesel. There was very little I could do with that engine - besides lacking knowledge everything was also difficult to access.

Maybe you can see if you can try the usual suspects, like fuel filter, ignition stuff, spark plugs. But if those don't result in any improvement, maybe it's better to have it looked at by the professionals.

[thelews]

Does it have a carburetor.  If so, I'd look (clean) the idle jets.

[J. Huber]

Thanks guys. It does have a carb -- and the mechanic I called when it first happened opined:

A. bad fuel (try a bottle of cleaner) or B. carb needs to be cleaned ($?)

As far as maintenance. Like I said, they winterize it -- which I believe entails changing the oil, fogging the block, and maybe the plugs? or not. actually not sure. $179 -- sure of that.

So it may be bad fuel and I need to clean the carbs... I may try one more hard run on the lake to be sure the Lucas gets worked in... I don't think I should mess with the carb -- do you all?

[graphic66]

Put some alcohol in the fuel. Isoproponol 99%. If there is water that will help, but I think if you had water it would affect the whole range of power. Probably gunk in your carb. I would try pulling the spark arrestor and giving it full throttle and choke it, over and over for a bunch of times. It may pull through the crude.

[thelews]

Are the idle jets accessible rather easily?  Simply pull them out, run some carb cleaner through them, blow them out and reinstall.  In my 190 SL that would take about 5 minutes.

[Norm]

I assume you have researched the impact of ethanol in fuels used for marine applications.  Your problems sound very familier to the problems being reported by boat owners across the country as more and more marinas have begun selling gasoline with up to 10% ethanol, which can have a significnat impact on fuel systems, including the fuel tank itself.   :'(

http://www.fuel-testers.com/marine_boat_ethanol_problems.html

Norm

[Cees Klumper]

What I mean by maintenance is the same stuff as on our cars - oil and filter change, fuel filter(s), new plugs, ignition checks, valve clearances - the works. Carburetors are not that expensive to have cleaned I believe. Winterizing could mean filling the (typically open, communicating with the water you drive the boat in) cooling system with antifreeze, unhook (and in the spring) recharge the battery and clean the bottom of the boat, then this could easily add up to the $170 or so - I know I pay a lot more for my cars tune-ups. So it may just be overdue for its regular maintenance.

[tuultyme]

If they fogged the engine for the winter did they change the plugs come spring.  I had the plugs fouled by the fogging oil.  When I owned a boat I put in an old set of plugs before fogging the engine and saved the good set for the following spring.  Some boats have a water separating type of fuel filter.

[J. Huber]

Thanks for all the insights. Here is an update. General consensus is it is fuel related -- possibly fuel contamination or something. Realizing that I have no ability to work on the carburetor myself, I was (am) going to take it in for a tuneup. However, the boat guy is booked for a ways out, so I decided to take it out once more and run the additive through a little more. I thought I'd try the old Italian tune-up, aquatic-style...

Well, boat ran good as always with throttle but still no idle ability. It just died when the throttle was disengaged. Resigned to failure -- I thought I'd try one last thing. I just wanted to really rev it and blow things out. Unlike a car, where you can just easily step on the throttle in neutral to run up the revs, with the boat it doesn't really work that way. Once you rev it up, the transmission grabs and it goes... So I started just punching it with short stops and starts. Looked like I was doing wheelies with the boat. My daughter was with me and thought it was all a blast... Anyway, after several of these in forward, I did a quick reverse punch... And bam! a fairly large "puff" of something exited the rear of the boat... My daughter said it was grey or green ? I heard it more than saw it really. Anyway, guess what? Boat immediately started idling perfectly -- ran it and tried it for another two hours that day -- it was like the day I bought it... I was stoked but what was it? a bit of muck?

[thelews]

Sounds like it backfired and may have blown out the idle jets.

[mdsalemi]

Well, the reversing certainly has nothing to do with the engine, merely the reversing gear in the outdrive.  But that kind of reversing behavior is what I would have to do to blow out crap that got sucked into the pump on a jet drive in days of yore.  Today my boat, like James', is a Mercruiser but thankfully with relatively problem free Bosch electronic fuel injection. 

I'm sure you know the score James--when you go and winterize it you fog the carbs as well as the spark plug holes.  Always add Stabil or some kind of fuel additive for storage and always store it with a full tank of fuel to minimize condensation.

[J. Huber]

Reverse has always seemed more responsive as far as torque (is that the right word?) than going forward.  So maybe it was enough of a gun to blow things out.