TOPIC: Decarb 72 6 HP Johnson?

Ok, so I picked up an awesome 72 Johnson 6HP Seahorse. It looks like it was in a time capsule for an unknown amount of years. I'm thinking it was serviced and hung on a wall....for 10-15 years, maybe more. All rubber is piable, and gaskets look great. The fuel lines are clear and not swelled. Compression "feels" good when pulling on the starter rope and the prop by hand.

My question is. I pulled the plugs to check out as much as I could see in the engine and there is ALOT of carbon build-up. Sticky almost powdery carbon. Do I need to pull the head, or can I shoot some Sea-foam into the cylinder head, let it soak over night and run a good seafoam treatment in gas? I plan on changing plugs, impeller and gear oil, but I do not want to pull the head unless I need to.

Suggestions/experience greatly appreciated.

I agree Matey, I wouldn't pull the motor apart just yet unless you have other issues! (Just my non-professional opinion, mind you.) It may take several applications of Sea Foam, but that stuff works wonders. It may cost you a couple sets of spark plugs, but I think you're on the right track there. Get ready for a lot of smoke when you first fire it up, you won't have to worry about mosquitoes for a while!

Take no chances. Replace the water pump impeller FIRST before trying to start it, or pieces could plug passages and fry that beauty.

Thanks for the advice guys. I went ahead and fired her up. 3 pulls with new plugs and it fired up, sounded great. Shut her down after 5-10 seconds. So I pulled the lower and the 4 screws holding the water pump housing are frozen. I guess I'll try some heat and penetrating oil? They're pretty stuck.
Also, my shift arm Is real stiff. I pulled the power head and I'm wondering how to loosen this thing up. Is there a way to get into the internals to clean up the old lube that's probably dried up in there?
I guess I'll be buying some new gaskets and a water pump housing, oh well. She's going to be my backup/trolling motor, so I guess it's worth it.