2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

[jsuggs]

I'm not sure about some of the technical terms. My boat was running great this past Sunday. About half way through the day I was getting ready to pull my wife on the kneeboard. As soon as I pushed the throttle forward to accelerate the engine just died. I tried again several times and the same thing happened. I finally thought to just take a look at the carb. What I noticed was that the flap on top of the carb was stuck open. I loosened it, started the engine, and everything was fine. It looks like there is a mechanism that pulls down on the flap to open it, and I assume when I push the throttle forward this mechanism should release allowing the flap to close. It seems this mechanism is not releasing. Does anyone have an idea of what I should do? Would a little grease on that mechanism fix this?

Thanks

 

[mkast]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

When the engine is at operating temperature, the choke plate (what I think you are calling a flap) is supposed to be fully open.

 

[jsuggs]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

When the engine is at operating temperature, the choke plate (what I think you are calling a flap) is supposed to be fully open.

Thanks for the reply. The engine was definitely warm because I had just got done wakeboarding. All I know is that the engine was stalling out on me when I gave it gas. When I raised this mechanism that pulls on the choke plate allowing the choke plate to move freely it ran fine at idle and when accelerating.

 

[Don S]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

When I raised this mechanism that pulls on the choke plate allowing the choke plate to move freely it ran fine at idle and when accelerating.

Not sure what you meant by the above statement. Is the plate closed or open when warm?
When the engine is warm, is the choke plate Open or Closed ? It should be open.
If it's closed when the engine is warm, then repairs or adjustment are in order.

 

[jsuggs]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

Not sure what you meant by the above statement. Is the plate closed or open when warm?
When the engine is warm, is the choke plate Open or Closed ? It should be open.
If it's closed when the engine is warm, then repairs or adjustment are in order.

Ok, here's what happened. The boat was running fine the first half of the day. Then all of the sudden I push the throttle forward to accelerate and it stalled. I started the engine tried again and the same thing happened. I did this a few times. I had no idea of what to do, but I decided to just take a look at the carb. I saw the choke plate all the way open and it seemed stuck so I messed with it and then pushed it closed. When I pushed it closed a little arm on the side of the carb raised up. Pushing the choke plat closed made this arm raise up. This allowed the choke plate to move freely. I didn't know if I actually did anything important, but I tried to start the boat anyway and it fired up and ran fine. I could accelerate with no problem. We stopped one more time on the lake to swim before calling it a day. While we were swimming I checked the carb again to see what that plate was doing. It seemed stuck open again so I pushed it closed. When we were ready to go I fired the boat up and we went without issue. I have no idea if the same problem would have happened if I hadn't checked that plate again and pushed it closed, but I can only guess that it would have.

 

[NHGuy]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

It should stay open when the motor is warm, but it will be able to pivot with finger pressure. If it's stuck after a shutoff and you need to give a push to free it up - it may be trying to close as the motor cools. Sounds like there is a bent link or something in the linkage restricting some part of the system.
The next time you go to the boat take off the cover and check to see if the choke is closed when the motor is cold.

 

[mkast]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

The next time you go to the boat take off the cover and check to see if the choke is closed when the motor is cold.

The throttle might have to be pumped once, to set (close) the choke plate.

 

[Don S]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

All you have to do is move the throttle just slightly, enough to move the idle adjustment screw off the high idle cam. At that point, the choke plate should be free to move open or closed.

NOTE:
They are still called high idle cams, but they do not have steps in them on marine engines. They are the same size all the way around.

 

[jsuggs]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

Thanks for the replies. I'll check it tonight to see if the choke plate is opened or closed with the engine cold. I'll also mess with the throttle to see if that helps. When the problem happened on the lake it stalled on me several times before I decided to look at the carb. A couple of those times it didn't fire up immediately so I pumped the throttle a couple of times to prime it again. It didn't make the plate close then but I look at it again tonight and post what I find.

Thanks

 

[Fishermark]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

A couple of those times it didn't fire up immediately so I pumped the throttle a couple of times to prime it again. It didn't make the plate close then but I look at it again tonight and post what I find.

Just to repeat what has already been said - and to make it clear - the choke will not close after the engine has warmed up. Simply moving the throttle will not make it close after it has warmed. Don and mkast are referring to the engine being cold in order for the choke plate to close when the throttle is engaged.

 

[jsuggs]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

Ok, so here is what happened this evening. I checked the choke plate with the engine cold and it was closed, but that could easily be from me messing with it last night. I started the engine and put it in gear, pushed the throlttle forward and it ran just fine. I did this a couple more times and no problem. I cut the engine off. The choke plate was open. When I pull the throttle into neutral a screw makes contact with the arm that pulls the choke plate open keeping it from moving. So I'm not really sure how the choke plate will close as the engine cools since this screw is pressing against the arm holding the choke plate open. Anyway I fired the boat up again, put it in gear, pushed the throttle forward and it died. The next time I tried it was fine. The next time it did it again and I swear I saw something come up out of the carb out of the corner of my eye and there was a pop sound. One of the times it started to die I pull the throttle back into neutral and this kept the engine running. I'm not sure what all this means, but I hope it's nothing serious. The carb was rebuilt last year because the float was stuck, so it should be clean. Any help is appreciated.


Thanks

 

[jsuggs]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

I'm starting to think the choke plate has nothing to do with the engine stalling when I give it gas. I'm thinking it might have just been dumb luck that it worked after I messed with the plate.

 

[81 Checkmate]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

Last night before you messed with anything as you are saying, was the choke plate closed on the carb?

 

[jsuggs]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

Last night before you messed with anything as you are saying, was the choke plate closed on the carb?

Yes, but that could be from where I was messing with it the night before. Also I realized last night like Don S. said earlier "All you have to do is move the throttle just slightly, enough to move the idle adjustment screw off the high idle cam. At that point, the choke plate should be free to move open or closed." The more I look at it the more it doesn't seem like the choke plate is the problem. Could it be something with the fuel filter?

 

[81 Checkmate]

Re: 2001 Mercruiser 5.0 220 Alpha 1 - Flap on carb not closing.

Ok when your motor is cold choke plate should be closed, as your motor warms it is either a elect or spring activated arm that opens the plate AS THE MOTOR GETS HOT to give the motor more air along with more fuel to advance RPMS. When you shut down your motor as it cools the flap will slowly close that way it chokes the motor to start. If motor is still hot when trying to start the flap should be open. I think your flap is working properly the way you are describing. Sometime on my boat when we stop, say to swim or pick up a skier, i turn it off and we do our thing, i go to start and it will not start in neutral i have to pump the throttle once and it will start. not all the time but every now and then.

1. Change your fuel filter at the carb. The little one at the base of the carb
2. Change your water/ fuel seperator canister.