I have a 1995 Formula 252BR with 454 Mag MPI (boat was re-powered at some point) with Bravo III.

Boat has been sitting for at least a year maybe more. Fuel was bad, basically varnish, drained 30 gallons from tank and then added a few gallons with rubbing alcohol to get whatever other water was in there. Will drain before refilling with clean gas and replace fuel filter and fuel/water separator.

Pulled starter. Its corroded and would not work. Solenoids seem to work.

Will replace starter. What else should I address given the motor has been sitting. Motor turns. There is corrosion on pulleys, manifold bolts, and other areas. Boat is raw water cooled and spent life in salt water.

Recommendations? Plugs, tune-up, compression test, leak down test, etc???

If I get things working right I would like to upgrade the motor given its the forged internals 4 bolt as I understand. Links to recommendations on builds. If I have to replace stuff I might as well upgrade.

Thanks in advance.

If the fuel was that bad, its probably been sitting for more like 3+ years.

Probably was. Got the varnish out. 30 gallons. That was fun.

Putting in fresh fuel with some rubbing alcohol and will then drain that as well before putting good gas in again.

Pulled starter. Flywheel has rust. Is there a way to clean it, CorrosionX???
Pulled plugs and cylinder looks clean inside.

Is there an easy way to tell if risers and manifolds are okay.

Whenever I wake a motor up from the dead,especially a mystery motor,I no nothing about.i pull all the plugs and squirt a small amount of marvel mystery oil or two stroke oil in cylinders. I make sure I have a full charged battery and a charger with a 50 amp or better start mode.i like to crank the motor crank > stop ,crank> stop ,crank > stop , you know just try get some oil in the crank and rod bearings. I like to disconnect fuel line and just run motor off a squirt bottle with gas. After making sure motor doesn’t rattle like a bubble gum machine then I know oil change,carb rebuild,fresh fuel,tune up won’t be wasted time

If it was sitting that long, for sure pull injectors and have them tested/cleaned. Plugged injector will scorch a piston right quick (coming from experience on that).

Changed plugs, impeller, cleaned risers/manifolds, replaced thermostat, flushed cooling system, replaced idler pulley, new fuel separator, got 91 octane chevron with royal purple octane boost in the tank after cleaning, and working my way to injectors. Did compression test and looked good with 140 on all cylinders. Motor ran smooth before plug swap and now runs tad rough after plug swap but at least now temps are holding normal and risers/manifolds stay cool. Have a shop nearby that cleans and certifies injectors so may go that route soon. Thinking I need to do cap and wires as well. Was concerned about hot risers and now they stay below 100 degrees (per infrared temp sensor) and motor idles around 160 degrees.

Shifting focus to drive to make sure that works and flushing trim pump which had chocolate milk for fluid. Got it apart and cleaning.