5.0 Merc Rough Start

[m3gumby]

Hey guys,

I put the boat on the ramp this Sunday and initially cranked but sputtered out. Long story short, engine got flooded and couldn't get it started. We took it home, I pulled out a plug and looked fouled to me. I have a west marine close so replaced the plugs for under $40. Tried to fire up after, same story as ramp. I let it sit overnight and decided to prop the butterfly valves open while trying to start, and sure enough it cranked.

I noticed that in moving the throttle forward, it looks like the butterfly valves are having a hard time keeping up with the fuel input. My guess is the red circled portion of the picture attached and is probably a vacuum leak, but how do I fix it? This makes sense with why it's flooding and stalls when I give it too much gas, that it's not getting enough air to ignite. Any advice?

 

[alldodge]

Hey guys,

I put the boat on the ramp this Sunday and initially cranked but sputtered out. Long story short, engine got flooded and couldn't get it started. We took it home, I pulled out a plug and looked fouled to me. I have a west marine close so replaced the plugs for under $40. Tried to fire up after, same story as ramp. I let it sit overnight and decided to prop the butterfly valves open while trying to start, and sure enough it cranked.

I noticed that in moving the throttle forward, it looks like the butterfly valves are having a hard time keeping up with the fuel input. My guess is the red circled portion of the picture attached and is probably a vacuum leak, but how do I fix it? This makes sense with why it's flooding and stalls when I give it too much gas, that it's not getting enough air to ignite. Any advice?

Sounds like you need to adjust your choke plate. When cold there should be 1/8 gap in the top. In the pic below your red line is the vacuum diaphragm which keeps the secondary's from opening until the rpm gets high enough. Also in the pic your choke plate is full open, if your engine was warm during this pic your OK. If the pic shows your engine cold and the plate open then you need to rebuild your carb because it is flooding the engine

 

[m3gumby]

The engine is on and warm in this pic, it just took it a minute to get started. How do I adjust the choke, thats kinda what I was lead to believe as well

 

[Bondo]

I noticed that in moving the throttle forward, it looks like the butterfly valves are having a hard time keeping up

Ayuh,..... Because yer lookin' at the choke flap, the throttle plates are down under the choke,....

How are ya startin' the motor,..?? What's yer method, throttle movements, etc,..?? Where's the throttle, when ya hit the key,..??