Currently have twin 496ho 2003. Little over 500 hrs. Motors run perfect, no miss, correct rpms, seem to be getting sooting only out of starboard motor portside. I could see it on my steering ram. Think it may just be a plugs and wires fix? I an no stranger to sooted up transoms my old ride had procharged 502s, sooting was a constant battle. Any suggestions would be greatly appreciated. Like the stock motor life style

current fresh fuel is best to use - not 3 to 6 month lay up fuel... Next - fuel pressure testing ? - spark plugs and wires -- especially if you have the original spark plug wires.

Scan the engine - operating temps at the scan are ? MAP sensor readings when scanning ? and of course fuel injector SERVICE is a must with any 496 - they suffer from contamination issues. They are good injectors but the crap they collect is unreal.

I have spark plugs and all Brand NEW wire sets for all 496 s. We actually are redoing the 496 s spark plug wires because I am so picky that I wanted the best EMI / RFI suppression that is not offered in any other plug wire.

The spark plugs I have are GAPPED correctly, its a fine wire and priced really well. Ready to install. I carry 600 spark plugs for the 496 s inwhich I get a price break on. I do not use the AC Delco spark plugss for anything.

If still rich / sooty the intake manifold GASKETS gen 1 design was not good - the gen 2 IM gaskets is way better for sealing and holding that seal over time.

Thanks for your input, I will be reaching out to you for plugs and wires in the near future, busy travel schedule for the next month.