engine choking out

[dmarshin]

I'm a brand new member and new boat owner hoping someone can help me diagonois a problem that just developed on my boat.
I have a 1995 Sleekcraft, 26 foot Enforcer, with a 7.4 Mercrusier and 502 HP Bravo I with a mechanical fuel pump.
I was on the Lake this afternoon for about an hour, boat ran great, then started to starve fuel, and gradually died. Fuel gauge read, 3/4 full. Got pulled in to fuel dock, thinking I ran out of gas. Engine started but was missing real bad and would not stay idleing.
Filled up both tanks but only took a small amount, 11 gallons one side, 19 gallons other side.
Engine started real rough, but wouldn't idle unless the RPM's were up. Would not go into gear without dying.
Towed it to the ramp and left.
Any ideas on what caused the sudden turn around. I'm hoping something simple like the fuel filter.
Sorry for the long post but know you want as much info as possible. Thanks

 

[ziggy]

Re: engine choking out

i don't have a clue about yer perticualar engine.

but have ya performed any tune up stuff to it? cap, rotor, plugs, plug wires, timeing

fuel filter sounds like a good start. when i got my used boat i had pluged up fuel filters.

have ya done a compression test? to see if ya got anything to work with.

have ya got a book on it? if not, get the oem service manual for it. great reading i'm sure.

have ya got a fuel/water seperator? maybe it's full of water

just a few ideas for ya....the oem service manual will give ya a lot more ideas though........

 

[Haut Medoc]

Re: engine choking out

Change the water separating fuel filter & post back your results, when tested in the water.......
Two minutes of sustained load at 3500 rpms will tell you if it was the problem or you need to look further....
Welcome to iboats, btw.....​

 

[dmarshin]

Re: engine choking out

Thank you for your help.
Took off the fuel filter and only about 3 teaspoons of water. Going to cut it up in a few minutes to check for debris.
Did find some debris, particals in the carbureator. My friend who is working on the boat for me thought the debris clogged the opening and made too much gas enter, thereby running so rich the engine could not stay running.
Will try and test it with the muffs first, then the lake tomorrow.
I will get back to all with the results.
Can't thank you again and this forum for all your help. It's my first reading of the day to help me learn more.

Doug

 

[Haut Medoc]

Re: engine choking out

Like I said, replace the water separating fuel filter.....
Since you see debris, I would check the filter screen where the fuel line enters the carb, as well as check the tube that goes from the fuel pump to the carb....
If there is fuel in that clear/yellow line, fuel pump failure is imminent....
That would explain some of your symptoms......​

 

[DayCruiser]

Re: engine choking out

1 teaspoon of water is not good much less 3

 

[dmarshin]

Re: engine choking out

My friend installed a new filter from the new fuel filter to the carburetor, cleaned the carburetor and ran it on the muffs for a half hour. Ran great.
My son took it to the lake Sat. and it ran great for 1 and 1/2 hours.
I took it out Sun. and it was hard to start, would not stay in idle and running real rough again. Barely made it back to the dock again. Black smoke coming from exhaust and running terrible.
Could we have more debris in the carburetor, doesn't make sense.
Any suggestions are much appreciated.

Thanks again,

Doug

 

[Coors]

Re: engine choking out

Change filters again, but black is choke on, or too rich.

 

[dmarshin]

Re: engine choking out

I will change them again tomorrow after work and hopefully get another test run in.

Thank you again,

Doug

 

[Fishermark]

Re: engine choking out

If you have water in the fuel separator (again), it's time to check your fuel tanks. I suspect you will also need to take your carb apart and clean out the fuel bowl.

 

[Windykid]

Re: engine choking out

Lots of black smoke= to much fuel.

Check plugs for fouling, and again that yellow tube for the preasance of fuel.

Tune up

 

[lee42lee]

Re: engine choking out

What does it mean if the yellow line has fuel in it?

 

[ziggy]

Re: engine choking out

What does it mean if the yellow line has fuel in it?

fuel pump failure.......

 

[Boomyal]

Re: engine choking out

What kind (brand) of carburetor is it?