Fresh water only.... I would not waste my money. Freshwater manifolds last 40 years or when someone screws up winterizing
$300 gets you parts for new motor
no need to worry about chain, oil pump or RMS your motor is just a puppy....... let it grow old before you worry about those things. you dont change oil pump on your car when you only have 20,000 miles. no need to worry on a motor that only has 570 hours
before removing pan, inspect it. may...
Not sure I would use a shop vac with arcing brushes and open framed motor for emptying a fuel tank. The fuel vapors go thru the motor.
It's a miracle you didn't blow up
Pull sender
Siphon out all fluid
Mix simple green and hot water. Fill tank 1/4 full
Reinstall sender
Drive down gravel road with potholes
Repeat
3rd time, use denatured alcohol on last drive
Siphon out, and let dry
Then fill up and go boating