Help, I think Ive tried everything.

[halltrail]

Hello all, my first post here. I have been doing a lot of researching and reading on this site. Two weeks ago, I purchased a 1985 Grady white seafarer. The boat had a completely new repower job done in 2000. Included a new 1998 4.3l mercruiser (2bl mercarb) and alpha one gen 2 stern drive. Engine serial number is 0m008448. The engine and drive have 20 hours total. The boat has been sitting for 13 years. I have the receipts for the work done to the boat. The engine would only turn over but sounded good and compression was pretty close to 180 on all 6. No more than a 5psi spread.
Currently, im having trouble with the engine stalling under load in the water. The spark plugs are wet and black smell like fuel. I think one issue is im running rich.

Here is what ive done so far:
Change oil and oil filter
Changed fuel filter
Replaced spark plugs and gap set at .45
Replaced Coil
Rebuilt the Carburetor (float weighed 9 grams, drop at 27mm and top at 14mm) All linkages are set to spec. Idle screw backed out 1 and ¼.
Replaced oil switch and sending unit
Replaced fuel pump with mercury 861155A 3
Replaced anti-siphon valve
Replaced starboard single piece manifold with Mercury two piece manifold (looked like the previous owner broke off the blue plug tabs and just left it plugged so the manifold was rusty inside and kept clogging up even after I flushed it)
Replaced gear oil
Replaced impeller (which was in great shape considering it was sitting for 11 years)

The only thing I haven’t checked is distributor cap and timing..but I am getting good spark. Also, the new fuel pump is running at 10psi. I set up some 3/8 rubber hose and fittings to use a fuel gauge. I think psi is supposed to be under 7. Is that enoughdifference to cause my problem? Im at a loss as to what else to check. She will idle in water and on muffs fine. But soon as im in gear and moving…she will stall out. I had to row back to the ramp the last time…about 75 yards…I know, you can laugh. It did look funny rowing a 22’ boat. Lol.

The interrupter switch seems to be working correctly by the way.

Any thoughts or ideas would be very much appreciated. Love this forum. A lot of what I have done is based on information Ive read on this site.
Dave

 

[alldodge]

:welcome: to iboats

I hear smell of fuel, the pump putting out 10 psi, leans me to, to much pressure, if your measurement is accurate. You have spark and your flooding. Did not look up your carb spec so if your correct with the settings then the next thing would be, is the float closing off the fuel when up to top of level?

 

[halltrail]

I think my carb serial number is 807764A1. How do i check the float to make sure it is closing off the fuel? I set the float at rest to 14mm. Thanks for the reply

 

[MikDee]

It sounds like a stuck carb float, or needle not shutting off gas flow? What's the spark plugs look like are they wet?

 

[havoc_squad]

10 PSI is too high for fuel pressure under 1800 rpms. That fuel is going to slowly sneak past that needle and seat into the carb body.

Expect that your Venturies are going to drip gas onto the throttle body and slowly flood your engine.

You won't notice a flooding issue going on at low idle in neutral very much unless its about to choke over and die due to flooding. "Slow" flooding typically affects the engine while under load at low idle.

Mercruiser service manual specifies that the electric fuel pump check valve may be stuck, you may have to temporarily block the fuel flow output for 0.5 second to 1 second to free it up. Link to service bulletin: http://www.marinemechanic.com/merc/distributors/mercurymarine/sterndrive/electricfuelpumptesting.PDF

Diagnose the cause of the fuel pressure being too high at idle and get it resolved, then if further issues come up, investigate them.

It also won't hurt to check the normal idle timing specs per Mercruiser service manual.

 

[halltrail]

Havoc, great information. Thank you . My updated post most have gotten lost in the Database problem. It turned out I had a lot of water in my fuel and that was causing the main problem for stalling. But im still concerned about the fuel pressure. So I will follow your adviThanks for the responses guys. I have been having a hard time getting the into the forum. I got frustrated with her and took it to a local marina. They cleaned the carb again in one of those dipping machines. But the big things was they did a fuel analysis ( dumped fuel in the jar). Im so mad at myself for night doing it myself. The jar was 90 percent water and 10 percent fuel...

Here is my post that got lost. I wrote it in word and copied it over....since the forum was having issues:

I initially ran the boat off of a separate 6 gallon tank...and then switched back to the boat tank and noticed no difference on the muffs. Didnt even occur to me to try it on the water. Duh. I guess with so many things to think about..i just lost sight of the most basic thing. Hopefully that was the primary problem.

Im wondering if that much water is a bad fuel seal in the filler, tank with holes, or just 13 years of condensation. I dont think the tank is bad only because i dont smell any fuel in the compartment or any fluid in the bottom of the fuel area.

I am still concerned about the fuel pressure but hopefully they will have a successful sea trial.

If all goes well, I then need to fix one of my bellows that is leaking. I will keep the updates coming. I will order a new float also.

Note to self: ALWAYS check the condition of the fuel.

​By the way, can I upgrade to a Racor fuel fiter with the water/glass bottom? I seem to remember reading about that somewhere?.