Merc 3.0 will start but won't idle--help, please!

[bigmacfan]

We took our 2002 Sea Ray 176BR with Mercruiser 3.0 out for the first time this season. Winterized by a professional last fall. We got caught by unexpected colder weather and wasn't able to run as much of the gas out as we would have liked for fall, so it was put away with about 3/4 tank of gas, but the winterizing person added fuel stabilizer to take care of this.

Yesterday, take it to the water....started fine...but wouldn't idle. I could keep it running by continuing to give it more fuel. Never actually put it into gear, but worked with it on the ramp for a couple of hours. Added some sea foam and topped off the 1/4 tank with fresh gas. I could finally get to idle briefly at 2800rpms but then would just start climbing rpms for no reason. Otherwise, I would give fuel to take to 2000rpms and it would just start falling and wouldn't hold an idle anywhere.

We put it up without issue...was running fine last fall. Couldn't get ahold of anyone to take a look at it this weekend and am home from the lake to do research on what could be the matter.

Any ideas out there?? Appreciate any help!!

 

[NHGuy]

Re: Merc 3.0 will start but won't idle--help, please!

So did you need to run it above 2800 rpm to keep it from stalling?
When you ran it did it run smoothly? Did it start normally each time? Did it stumble, smoke, or do anything else unusual?
Maybe you should read the sticky post about un-winterizing too.

Stay tuned, more experienced people will be along eventually.

 

[bigmacfan]

Re: Merc 3.0 will start but won't idle--help, please!

Thanks for the first reply! It ran smoothly and started great, it just wouldn't continue to run without me continuing to pump fuel through it. Whenever I quit the pumping action with the throttle it would die. I have never experienced anything like this.

I followed the same procedure for the first trip out that I have since I got it (4th spring with it) and we haven't ever had this issue. It has always been hard to start the first time of the season (and it was this weekend, too), but it has never had problems continuing to run.

 

[ljenks]

Re: Merc 3.0 will start but won't idle--help, please!

This sounds IDENTICAL to the issue I just fixed on my 4.3. It ran great all last year, winterized it & put up for the winter. When I went to dewinterize, it was very hard to start, and if I did get it started, I had to feather the gas & keep it above approx. 2500rpm or it would die.

I pulled the carb apart on mine & for the most part it was clean, but found the pilot jet (jet that meters the fuel at idle), partially clogged. Cleaned that out & now it runs like a top.

Hope this helps

 

[Mr South]

Re: Merc 3.0 will start but won't idle--help, please!

Yeah I was having the same problem early last week. Cleaned the carb and now it runs perfect, so try that first and see what happens. Mine is also a Merc 3.0

 

[fat fanny]

Re: Merc 3.0 will start but won't idle--help, please!

From what your describing it sure sounds like yoou need to take a look at the entire fuel circuit pick up tube in tank along with the screen,anti siphon valve, fuel filters(pumps and carbs) fuel lines,and fuel pump along with as suggested a carb tear down. sounds like interuppted fuel feed something is starving the system!

 

[Hansolo99]

Re: Merc 3.0 will start but won't idle--help, please!

Yes this is a carb problem. Nothing big take it and clean it and that's it. Don't try and mess adjusting any screws, it need a good cleaning that's it.

 

[swihartart]

Re: Merc 3.0 will start but won't idle--help, please!

were the plugs changed? I've read where fogging oil can foul plugs after spring start and gum up carbs. There was a thread not too long ago about this very problem...just an idea...