Fuel Pump Issue (Urgent help!)

muskokamarc said:
Thanks. I have another mobile marine mechanic (https://corcoranmarine.com) who is fair priced and knows his stuff that I am beginning to use for more than just my winterizing.
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No worries. Rob was the on-staff mechanic at Hindson Marina where I have been, and left to start his own business. He was very good, honest, and a nice guy. So if for some reason you can't get your guy, you have another name to try.
 
scoflaw said:
Diaphragm has ruptured and dumping fuel down the carb. It's flooding your engine when motor is off. Never hurts to rebuild a carb.
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So after the tune up and carb rebuild, the boat still seems to NOT want to start after I drive it and let it sit for an hour or so.

Went for a 45 min drive this past weekend and then stopped for lunch. When i tried to start it to leave, it was turning over but not starting, so I gave it full throttle in neutral and it got going... What made me nervous was the visible fuel that was sitting ontop of the block right next top the carb... Sounds like it is flooded with fuel, but i am not sure what to do to fix it?

Is it likely the fuel pump or diaphragm as some have suggested?
 
scoflaw said:
Be nice to pinpoint the problem with the hatch open
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My mobile mechanic who is aware of the carb flooding after the marina rebuilt the carb (and adjusted the float needle twice now) is suggesting to go back to the marina and ask for a brand new carb with a small discount given the rebuild did not resolve it.

He does not believe it's a fuel pump issue because I am getting excess fuel.

Going to call the Marina and see what they quote for a brand new carb...
 
But I am also wondering if the engine is just tired/old and could be a compression issue? I just don't get why that would only cause issues on restarts after the boat is sitting...

I did a full tune up (spark plugs, spark plug hi tension wire set, distributor cap and rotor, fuel filters, OEM ignition module, adjusted/rebuilt carb) as they suggested below with no difference and now I am just wondering if the engine needs to be rebuilt?

"Customer reports boat is difficult to start. Can't be started without lots of throttle. Wondering if carb rebuild will help. Checked for water in fuel - none. Checked under distributor cap - original sensor. Oil and fuel filters are Sierra, so if the ignition components are Sierra, then the life expectancy of those parts is minimal. Plugs are old. Compression test: 1 - 120, 3 - 130, 5 - 125, 7 - 120, 2 - 115, 4 - 120, 6 - 125, 8 - 130. Engine timing set to 12 deg BTDC. Customer mentioned rebuilding carb. Other than rebuilding the engine, new ignition components and the timing set to spec will help the most for runability. Yes the carb should be done, but not before a proper tune-up. This engine has in excess of 600 operating hours and is getting tired."
 
Well if it has a new needle and seat and the float is adjusted correctly it could be the pump is putting out too much pressure. If the engine runs fine when running, why replace it?
 
scoflaw said:
Well if it has a new needle and seat and the float is adjusted correctly it could be the pump is putting out too much pressure. If the engine runs fine when running, why replace it?
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Makes sense. I guess i will just bring the boat back to them to look at.
 
There is a compression washer that goes between the carb body and the needle valve seat that if left off will result in flooding.
 
Wanderer 290 said:
There is a compression washer that goes between the carb body and the needle valve seat that if left off will result in flooding.
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Noted. I hope that a marina would not forget something like this... Will mention this along with the fuel pump for things to look at.
 
Boat is being dropped off tomorrow for them to take a look at the flooding issue. Fingers crossed...
 
PlayDate said:
Find a new mechanic.

600 hours is nothing on a well maintained gas engine. If the carb is leaking....just get a marine Holley to replace it and be done with the throttle nonsense to start it.
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This may sound dumb... Is a marine Holley a special type of carb or just a brand of carb? If they told me it would resolve the flooding issue 100%, I would do it.
 
Holley is a brand. Got big making carbs for performance street hot rod and racing engines. One of the biggest and best, IMO...

Rochester, Holley, Carter, Edelbrock and Weber are all popular manufacturers that make carbs made for marine use.

There are models of Rochester, Holley and, sometimes, Carter and Weber that can be interchanged.

May the gods forgive me for saying this, but it is like saying what is your favorite oil? 99% have their favorite, and carbs can be placed in that grouping.
 
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muskokamarc said:
Oh ok, so Holley is an online store. My mechanic said my carb is a 4-barrel rochester and is about $1500CAD brand new. Is there something special about Holley or should i just get an OEM Mercury carb?
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Getting OEM makes for an easy swap. BUT........... Not always the best choice. Also check out Jegs or Summit racing. They are hot rod suppliers and do sell marine carbs of all flavors.

Plus these guys are Aces for rebuilds. Have used a couple of times with 100% satisfaction.
https://flyingfishcarburetors.com/index.html
 
I am going to give some information to the mechanic in writing (see below) since I won't be able to see him in person when i drop the boat off.

Please let me know if you have any other suggestions on what I should mention.

"The engine usually starts up fine on the first attempt with a bit of throttle. The engine is flooding on restarts after it is driven and sits for a while (30 min – 1 hour). On restarts, I have to put it in neutral and wide open throttle in order to get it to try and start (it does not always start when I do this).

Fuel leaks out beside the carb on the engine block and there is a strong smell of gas.

Once it sits long enough and I can get it restarted, I need to take off fast or else it will bog down and not restart.

When I brought the boat back to the marina after the carb rebuild and tune-up, the needle valves/float were readjusted, but it is still flooding.

- Is there still an issue with the Carb?
- Can you test to see if it is the fuel injection system? The fuel could be coming out too fast. Is there a way to check this and see if it needs a new fuel pump? Diaphragm may have ruptured and is dumping fuel down the carb when the motor is off."
 
muskokamarc said:
I am going to give some information to the mechanic in writing (see below) since I won't be able to see him in person when i drop the boat off.

Please let me know if you have any other suggestions on what I should mention.

"The engine usually starts up fine on the first attempt with a bit of throttle. The engine is flooding on restarts after it is driven and sits for a while (30 min – 1 hour). On restarts, I have to put it in neutral and wide open throttle in order to get it to try and start (it does not always start when I do this).

Fuel leaks out beside the carb on the engine block and there is a strong smell of gas.

Once it sits long enough and I can get it restarted, I need to take off fast or else it will bog down and not restart.

When I brought the boat back to the marina after the carb rebuild and tune-up, the needle valves/float were readjusted, but it is still flooding.

- Is there still an issue with the Carb?
- Can you test to see if it is the fuel injection system? The fuel could be coming out too fast. Is there a way to check this and see if it needs a new fuel pump? Diaphragm may have ruptured and is dumping fuel down the carb when the motor is off."
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Don't mention fuel injection in same argument concerning your carb. Did you mean fuel "Pump"?
2 different animals
 
Good point, I just think that it’s actually the fuel pump that needs to be fixed now and I don’t wanna waste time with the carb
 
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