Hello I have a 1995 islander 272 w/454 carb engine w/500 hours. The sucker is hard to start after it sits for like a week. And than once i got it started it putters than starts to run right. I have changed several parts all to merc oem parts. Did a complete tune-up (cap,roter,plugs). Changed the ignition switch because i thought it was the electric choke. I put new batteries in this year as well. I have a stereo w/amp and speakers all hooked up straight to the battery not going through my switch.
I was wondering would this cause the starting problems sometimes. I spoke with a mechanic and he said it can cause the sputtering. What do you guys think. I know since it is carburetter it takes long to start.

I would say that is normal for a carbed motor. Do you pump the throttle a few squirts before cranking it?

My Baja is carbed and use to be difficult to start at times when I first bought it. I realized my timing would walk on me if the distributor bolt was not tightened and locked down, which would retard my timing bigtime. Once I got my timing right, my battery went down a bit over the winter, causing another hard start. I charged battery and now starts right up. I clear my carb out each time I start the boat by putting the boat in neutral and pushing the throttle about half or more forward. Keeping the throttle there and starting the boat, it starts right up. Just get ready to bring the throttle back down when it does.

If it has the original Weber carb on it then it starts like every other Merc carb motor that sits for week or more.

+1 my weber carb that was on my Baja Outlaw when it was a factory 502 mag did the exact same thing. sat for a week she was a little hard starting. Wasnt that bad though. I think they leak down or something. They are a better boat anchor than a carb. Get you a nice holley!