Engine flooding after shutting off engine

[LockedupXJ]

Hi guys, I just purchased my first Searay its a 1994 200 Signature. Its has the 5.0 Mercruiser and Alpha 1 outdrive. My problem is that when i shut the motor off at the lake (after running for approx. 10 min or longer) and try to restart it after sitting for more than 5 min it acts like its flooded and i have to open it to WOT and crank a few times and it will fire and run roughly untill it cleans up and then its fine untill i shut it off again. I have tried rebuilding the carb, new plugs, wires and also checked the timing with no success. Also there is a line other than the main fuel line that runs from the fuel pump to the left primary ventury (when looking from the front of the motor). I am not sure what this does but it is full of fuel everytime i have the problem. I can take pictures if that would help visualize it. Also theres only 135 hours on the boat. Any help would be appreciated. :thumbsup:

 

[JediJD]

I'll throw out some random thoughts till the experts chime in.

Assuming its a "hard start hot" engine sends me first to the basics...timing, for example. Next, do the plugs look wet or sooty? Is the engine running rich? Can you run the mixture screws in without reducing rpms?

If the basics are all good, next come more exotic problems. I would be looking first at fuel pressure. What is going into the carb? When you turn off the engine, residual overpressure could be the cause. Also, when you rebuilt the carb, how were the float levels? Unlike an injected engine, carbs don't usually force fuel into the manifold. Fuel has to either be drawn by negative pressure or drip there. I would also want to look down the throttle body immediately after shut off and see if I see any residual fuel dripping or spraying into the manifold.

 

[Oldsman]

Did you epoxy the plugs in the carb? They are bad about leaking and flooding the engine.

 

[LockedupXJ]

Did you epoxy the plugs in the carb? They are bad about leaking and flooding the engine.

No i wasnt aware of this, is there a writeup on it or a section?

 

[Quint4]

The line you are referring to should not have fuel in it. It means your fuel pump has a ruptured diaprhagm....replace fuel pump and see if that solves your problem.

 

[LockedupXJ]

Well i finally got enough time away from work to start tracing down the problem and it turns out that it was indeed the fuel pump. I pulled it off the motor and took the pump apart and the diaphram looked to be dry rotted and was cracked pretty bad. The boat had sat for 1 1/2 years prior to me buying it so i link it to that. Also just a tip to everyone, Instead of buying an exspensive fuel pump from the a boat shop or werever and paying $100 plus. I spent some time looking around and found that i could get the same exact fuel pump at Autozone for $50. Its the actually marine pump not a regular car one. I will get the part number tommorow and post it up. Everyone may already know this but i thought it was pretty sweet :thumbsup:

 

[Spookeay]

I spent some time looking around and found that i could get the same exact fuel pump at Autozone for $50. Its the actually marine pump not a regular car one. I will get the part number tommorow and post it up. Everyone may already know this but i thought it was pretty sweet :thumbsup:

You had better make sure of this....
This is the one of 3 engine parts you don't want to make a mistake on....... It could cost you your life for $50.:wow:

 

[OldSkool]

Once again boats and cars are not created equal. As long as it's marine your good to go. I have used auto parts stores and saved some money, just need to make sure it's an apples to apples replacement.

 

[Quint4]

What Spookeay said.

 

[LockedupXJ]

Heres some comparison pictures. As far as i can tell it is an identical match. The part number is Airtex 60600 or a Carter 0-3000 is the same thing.

And heres one of the new boat

 

[Quint4]

They do not look identical but it does have the sight tube nipple which is encouraging.
It may be okay, but I would stick with OEM for fuel system components. Boat looks good.

 

[muskokamarc]

The line you are referring to should not have fuel in it. It means your fuel pump has a ruptured diaprhagm....replace fuel pump and see if that solves your problem.

I think my boat is having the exact same issue. Last year I drove the boat for about 30 minutes and then turned it off on the lake. It wouldn't start back up after about 30 minutes. It was turning over fine, but wouldn't start even with throttle. After sitting close to 45 minutes, it finally started with throttle.

My boat is currently at the marina and they are going to do a carb rebuild, but I've noticed that the little clear line almost always has fuel in it as well. Should I have the carb rebuilt and replace the fuel pump as well?

 

[Chip S]

My boat is currently at the marina and they are going to do a carb rebuild, but I've noticed that the little clear line almost always has fuel in it as well. Should I have the carb rebuilt and replace the fuel pump as well?

If the line has fuel in it I would replace the fuel pump first. The carb is probably fine. If you are still having trouble after replacing the fuel pump then have the carb rebuilt.

 

[muskokamarc]

If the line has fuel in it I would replace the fuel pump first. The carb is probably fine. If you are still having trouble after replacing the fuel pump then have the carb rebuilt.

What would cause this line to basically have permanent fuel in it even when the boat hasn't been running?

 

[Chip S]

Fuel in the line indicates that the fuel pump diaphragm has ruptured. In a car the fuel would spill on the ground but the line captures it in a boat for safety reasons.

 

[muskokamarc]

Fuel in the line indicates that the fuel pump diaphragm has ruptured. In a car the fuel would spill on the ground but the line captures it in a boat for safety reasons.

Ok, this should probably get fixed first then. Will it require an entirely new fuel pump or would they just replace the diaphragm.

Also, what effect does this have on the carb if the diaphragm is ruptured? Where exactly does this line connect to, the carb?

 

[Chip S]

Ok, this should probably get fixed first then. Will it require an entirely new fuel pump or would they just replace the diaphragm.

Also, what effect does this have on the carb if the diaphragm is ruptured? Where exactly does this line connect to, the carb?

I'm not a mechanic so I can't say for sure if the diaphragm can be replaced. Usually an entirely new fuel pump is installed. I believe the line connects to the carb.

 

[muskokamarc]

Well i finally got enough time away from work to start tracing down the problem and it turns out that it was indeed the fuel pump. I pulled it off the motor and took the pump apart and the diaphram looked to be dry rotted and was cracked pretty bad. The boat had sat for 1 1/2 years prior to me buying it so i link it to that. Also just a tip to everyone, Instead of buying an exspensive fuel pump from the a boat shop or werever and paying $100 plus. I spent some time looking around and found that i could get the same exact fuel pump at Autozone for $50. Its the actually marine pump not a regular car one. I will get the part number tommorow and post it up. Everyone may already know this but i thought it was pretty sweet :thumbsup:

Wish i had actually taken your advice and tried the fuel pump first! I have the exact same issue still, even after a full tune up and carb rebuild. Going to get the fuel pump replaced and pray this solves the issue.

 

[Bill Curtis]

Airtex is a major marine fuel pump manufacturer for OEM parts that get painted OEM colors and price tag triples.