Boat Misfires, or bogs after sitting a few days.

[paczowski123]

well as it says my 1998 bayliner with a 4.3 190hp mercruiser will misfire and bog if it has sat for a few days. However it only does it on the initial attempt to accelerate, it will slowly clean its self out and from that initial time it will run fine for the rest of the day. It will also only do this if it has sat more than a couple days otherwise it will not do this. for instance if i use it lets say after two days it will be fine, but this past week it sat all week and i didn't use it and it did it. I tried to accelerate and it bogged down and slowly accelerated and then cleaned up and was fine the rest of the day. Does this sound like anything i should look into, maybe a bad distributor, plug or wire? that maybe needs to warm up in order to preform better? Or maybe a partially clogged port on the carburetor? Has anyone experienced anything like this? this is my first I/O so idk if its normal to run harsh upon warm up or if it seems to be an actual problem?

 

[Don S]

Re: Boat Misfires, or bogs after sitting a few days.

Is it carbed? Choke too tight? Is the boat new to you?

 

[paczowski123]

Re: Boat Misfires, or bogs after sitting a few days.

Yes it is carbed, I do not know about the choke being too tight how would I check that? Yes, the boat is new to me and I bought it from him after it had been winterized and it did it that first time as well. but then I used it almost every day and was fine. Then after sitting last week while out of town I went in it yesterday and it did it by after the initial accel it was fine. It's almost as if it needs to clear out or something.

 

[Don S]

Re: Boat Misfires, or bogs after sitting a few days.

Remove the fuel filter and empty the contents of the old filter in a clear container and see if there is any water in it. Install a new filter, do not re-install the old filter.

 

[paczowski123]

Re: Boat Misfires, or bogs after sitting a few days.

Ok thanks I'll do that. I'd assume that's the black oil filter looking thing on the front left of the motor with the fuel hoses running to it? Is there anything else I can look into if that doesnt help? Such as the things I previously mentioned? Or would that kind of stuff cause a constant problem? How often do I need to change the spark plugs for future reference? And what's a good oil change interval?

 

[paczowski123]

Re: Boat Misfires, or bogs after sitting a few days.

Would my boat have what is called a thunderbolt ignition system? I was looking online at parts for doing a tune up for the plugs wires cap and rotor. Most are listed as thunderbolt ignition, is that what my boat would have?