ran the sunsation yesterday for the first time and ended up with a filthy transom.

454 mag carb
stock exhaust , no muffler

did a search on the subject and from what i found , this is somewhat normal for a boat with an integraded swim platform?

it has been sitting for over a year with 1/2 tank of gas with stabol in it. i added 30 gallons of fresh gas before dropping her in. put new plugs (.035 gap) before taking her out also.
idle was very ruff till she warmed up then smoothed out fine. lotsa smoke at first also. boat ran wonderfull all day inspite of the dirty transom.

is this really normal or could the stabol have something to do with it?

thanks for all your help guys.

make sure it's in tune, timming, air fuel mix, ect,ect, run 87 oct gas and if it still turns black put an MSD box on it.

I think it is normal for any efi mercruiser motor to have a sooty transom since they are set up so fat, but fat is better than lean

there is a thread on page two of the tech page. MSD 6m-2 go read that.

LOTO, I have the same engine (carbed 454mag) and had the same problem last season on the first run. Boat ran fine, but had a filthy transom by days end. Turns out the choke was stuck partially closed. Fixed that and no more dirty transom. May be worth a look. Andy

bayou outlaw , thanks!
ill look into it. be nice if its that simple

It could have been fogged down before being put away also, run it again after cleaning up the transom and see if it stays clean.

I've noticed that early and late in the season when the water is cold I get more exhaust residue on my transom. Once the water warms, I have little to no exhaust residue. I have a 454 Mag MPI and don't have an integrated platform.

The smoke was probably the fogging fluid burning out of the motor. As for carbed motors, they tend to idle a tad rough until they warm up. You may also be rich on your carb jetting to give you a black transom, but i would see if it clears up after a couple tanks of good fuel.

Lotoparty - my old 252 Islander had the same problem, it also had an integrated swim platform. One time it was particularly bad and I cleaned up the flame arrestor and that eliminated a lot of it. My old 252 had a carbed 454 in it. I didn't let it bother me too much, the boat ran fine, I just cleaned it up after every use. You may want to check the choke though, that could be some of the culprit. I have read a lot on this too and a lot of people said richer was better than lean so I left it alone.