Merc 2.4 Bogs out of the hole,


Senior member
May 9, 2004
Cruising area
Malahide, Dublin
Boat make
Hydrostream V-king, 650SS OCR ,Ring 21, Ring 18, Phantom 18.
300Hp Mercury 2.4, 130 Yamaha, Bridgeport EFI, XR6, Merc 200.
I have been going over my boat trying to get it up to scratch, one of the things I did was time the engine as it wasn't quite right last time out. First I decided to remove the spark advance module not paying any attention to how it was supposed to be wired to the engine. I re-timed the engine by the book and tried to start it, it wouldn't fire. So I thought ok, I'll put the spark adv module back on. Not remembering how it was wired I took out the wiring diagram and it turns out it was wired up wrong in the first place. It was wired with the ground on the block and the three wires across the three coils on the top switchbox?????
I re-attached the module and fired the engine up. Is this just coincidence that it didn't fire when it was removed or is there something else.

Second part of my question, when I put the boat in the water and started it, the engine sounded a little rough, and started to die. I gave it a bit of throttle and it picked up, slowly let off back to idle and it was fine. I thought I'd take it for a run and see how it goes, when I pushed the pedal it it totally bogged down, and the more I pushed the more it seemed to struggle until it hits a point where it just snaps to life! The boat takes off but at the end of the run when I let off the throttle it bogs up again and dies. But it still restarts again without any trouble!

Has anyone any idea what this might be, thanks in advance for any ideas.

Also I have just found out it is probably a ModVP engine, if this helps at all????

Thanks again, Alan


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2nd part bogging down

I too have experienced this, appears to happen when you flood the engine too much hit the choke and it roars into life. I think it because my XR2 has an electric fuel pump and puts too much fuel in when I rev it without letting it go onto the plane. Only happens occasionally though. If you free rev the engine I dont get the problem it only occurs under load.

Not sure that helps a lot but if it happens again try pushing the choke in when it bogs down?
I Think

I could have it figured, I started going through the entire electrical system, and found a bad plug lead.

Lesson to be learnt, always try the simple things first. I just hope I haven’t spoken too soon.

I had checked out the flooding idea as I also have an electric pump, fuel was flowing out my high speed jet but it was just some crap stuck in the float valve. I don’t have a choke, it's an enrichener valve.

Thanks for your reply, Alan..

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