5.7L Marine power idle propblems

[wired1236]

I have an '06 carbed MP 5.7l. It idles rough and dies when you go to put it into gear which I know being the first time out could be a few things...water in gas, gumed up carb, plugs, etc. I turned up the idle screw to get from 550rmp to 900rmp but no help.

I have a strong feeling however it's a gumed up carb. Before I started it this spring, I took off the fuel filter, that I put on new last fall, and it had green sluge on it so I changed it with another new one. I had this little bird on my shoulder thinking I should check it since the boat, at the time, didn't have a flush kit on it last fall therefore I didn't run the engine after I put the Stabil in the tank. (I just don't trust those fake-a-lake things). So my thinking was that the fuel system past the gas tank didn't get any stabilzed fuel and the old fuel sat in there all winter.

I have an appointment this Tuesday to take it in and have a mechanic take a look. He's telling me it's probably due to H2O in the tank but I'm going to tell him to check the fuel filter for water and clean the carb first. Draining/wasting 37 gal of treated fuel at $4.00/gal just seems wrong.

Any thoughts before I take it in would be appreciated!

 

[Bondo]

Re: 5.7L Marine power idle propblems

Ayuh,.... Even if ya got Water,.... It's on the bottom of the tank,....

Pump it out, 'n the rest of the fuel is, well, Fuel...

Look up Fuel Polishing...

 

[wired1236]

Re: 5.7L Marine power idle propblems

OK - so I guess you mean pump it out regardless? I doubt there is water in it as the tank has been full all winter and it's stored inside my semi-heated garage but i would agree. It's probably not a bad idea just to clean it out now.

What's your thoughts on the probability of a gunked up carb? The boat runs fine at 1000rpm and above. I just can't get it to idle as high without turning up the idle speed and then go into gear w/o dying. From what I have read, that means pulling the carb and doing a thorough cleaning, not just spraying some cleaner in the throat. I think for that, I'm going to let the pros handle.

 

[Bondo]

Re: 5.7L Marine power idle propblems

From what I have read, that means pulling the carb and doing a thorough cleaning, not just spraying some cleaner in the throat.

Ayuh,.... That 'bout sums it up,... The dirty spots can't be accessed without a Complete tear-down...

 

[wired1236]

Re: 5.7L Marine power idle propblems

Update-

Had the carb cleaned out by a mechanic. He also noticed the two idle screws where broken/stripped so he replaced those. Also the choke was not adjusted right. Did all of that and works better than ever before. Thank God for good mechanics. I would have spent hours and probably never got it right.

 

[QC]

Re: 5.7L Marine power idle propblems

Thanks for the follow-up!!!