Just bought a new boat (new to me that is) and have started or plan to do the following:
1. New water pump (in the process)
2. Check lower unit fluids (in the process)
3. Top off and charge batteries
4. Will run 1 1/2 to 2x oil the first full tank of gas per local mechanics suggestion (motor hasn't seen a lot of action in the last three years - run ever so often but not much).
5. Check function of oil injection - compare fuel use to oil use
6. Decarb
7. Install water separator filter

Any other suggestions related to the motor? Spark plugs were put in new last summer - I imagine they will need to be replaced after the double oil and decarb process - correct? When would be a good time to mix some seafoam into the fuel (have read alot about it here)?

Will also be packing the trailer bearings. Already replaced the winch strap. Trailer lights all work. Pumps all work. Trolling motor works. Nav lights work.

Am I missing anything?

Thanks in advance for your help and suggestions!

Safety equipment?

if its over 16 feet you'll need a throwable floatation device, life jackets for everyone on board. Oar, fire extenguiser, horn, and check the emergency shut off to make sure it WILL kill the engine when pulled.

Good tip Kingfisher - should have mentioned that I will be bringing over all that stuff from my previous boat. Thanks though!

Drain the fuel tank(s), inspect for debris and/or rust. Refill with fresh fuel.

Inspect all the fuel lines (including under the hood) for any sign of cracking or stiffness.

Check the functioning of the fuel primer bulb, make sure the line holds pressure.

Inspect engine wiring harness & spark plug wires, look for frayed, brittle insulation, corrosion.

Inspect your accessory wiring, look for half-axxed do-it-yourself repairs, make sure things that need fusing are fused.

You have oil injection - premix at 50:1 will double your oil + give you a safety margin if the injection don't work - wouldn't want to contradict your mech, but if you double that...well, that'll be an awful lot of oil.

Test the functioning of your overheat & low/no oil warning.

Familiarize yourself with the cold start procedure of your new motor.

Soon as you get a chance, take compression readings so you have a baseline for future testing.

Have fun!

Thanks jtexas - I am going to do what you suggested with the 50:1 mix, just didn't express it that way. 50:1 oil/fuel mix in the tank, fill the oil resevoir and mark level, run and compare fuel use versus oil use - correct? Thanks for the other tips - pretty much done most of them but not all.