I just picked up a new to me 38 TG with Chief 650 blower motors. The motors were fully rebuilt from top to bottom by Chief engines 5yrs ago and today have 10hrs.
The boat sat for the last two years. Before I try and start it what steps should I take? Drain fuel, new plugs etc....

Man Im no expert but I would definitely change all the fluids, filters and at least the raw water pumps. Put some fresh gas in it and fire those bad boys up! I would absolutely not run them over 3500 rpm until you know everything is working and all the old gas is out. I also just for my own peace of mind would run them until I know they are at full operating temperature then shut them down and let them completely cool down. Ive done that with all of my engines and its worked for me. Good luck and post some pictures as soon as you can. Good Luck!

in addition to above..might not be a bad idea to spray some lubricating oil into each cylinder to dress the piston rings. 2 years isnt “that” long..

Assuming the motors haven't been rolled over in 2 years - Pull the distributors and prime the oil pumps (if you could drain the old oil out and refill all the better) + shoot a bit of oil into the cylinders and then roll the engines over by hand just to ensure the rings have a chance of not breaking from being stuck to the walls.... once everything is free, Fire the engines up on fresh fuel, change the fluids and then put in new plugs

GREAT Idea on lubricating the cylinders before you fire them up!

Now you must post pics!!!!

You may find manifold and block drain plugs loose or missing if the engines we're winterized or preserved. Hose clamps may be loose at the raw water pumps.

also pull the bowls off the carbs and clean them . probably some crap in there , and not a bad idea to change the needle and seats .

No pic

I'm not an expert but at the minimum I'd probably drain fuel, have a couple fuel filters on hand to change after a few minutes of running, new plugs, shoot some oil in the cylinders, definitely new water pump impellers, then I'd pull the kill switches and spend an hour or so cranking them over at intervals long enough you don't burn up the starters to get the oil flowing - and needless to say fresh oil and filters.

Before I used it I'd pull the drives, understand how old bellows, etc are. Check gimbal bearings and put fresh drive lube in before I reassemble. Bellows are a basic maintenance item and if it's been sitting a couple years those are dry rotted and likely need to be changed.

Good luck. Post pictures