Re-awaken a 165hp I-6

[Kruegs35]

I just purchased my first boat. It was sitting for a few years due to a incomplete transom repair. Supposedly, the boat ran great before then. I planned on changing the fluids and flushing the motor. What else should I do before I try to start the engine?

 

[wahlejim]

Of it were me, just for piece of mind before cranking it, I would change spark plugs and if there is corrosion in the distributor cap, I would change that and the rotor out. Examine the plug wires, electrical connections to the engine AND the grounding connections and make sure they are clean down to shiny metal. Change the water/fuel filter/separator, if you don't have a cannister one, add one, if any gunk is in the fuel lines, this will catch it before it reaches the carb. Clean other fuel filters at carb and open the carb up and check for any varnishing from old fuel. Not much us worse than constantly cleaning a carb because old crud keeps getting caught in it.

Other people may disagree with me on this next one. I would manually turn the engine slowly a couple of cycles to make sure it is not seized and turns without any weird noises. Also, if any corrosion has formed in your cylinders, this will "polish" it away. All of this is preventative but could prevent major damage if you just hook up a battery and crank away. You will also be able to feel if you do have compression.

I would personally do all of this before even hooking up a battery.

 

[alldodge]

Agree, pull plugs and spray some oil in each cylinder, then crank over by hand a few times. If all is good crank it over a few seconds on the battery. Install plugs, change fuel filter, run engine off a gas can not the tank, might have some bad gas in there.

 

[harleyman1975]

Plan on a new impeller as well.

 

[Kruegs35]

Thanks everyone.

 

[biggjimm]

If you don't know the history of this boat, I'd pull the drive & check the gimbal bearing & u-joints & replace the bellows & probably the lower shift cable while your in there.

It can get expensive right up front but you'll have a boat that you can rely on for years to come. I've got one that sat for about three years & I'm up around $800-$900 in repairs & maintenance. And it was already mine. But it'll be good for a while now. Good luck & enjoy your new toy. Jim.

 

[bobturismo]

We usually fill the cylinders with marvel mystery oil overnight, then hand crank to push mmo out of the spark plug holes. Just as Jim suggested.

 

[Kruegs35]

So I have had no luck getting the engine to turn by hand. I've had Marvel Mystery Oil sitting in it for about 2 weeks now. I pulled off the cylinder head and the two outside cylinders still have oil sitting, while the others seemed to have soaked through. I also tried hitting the pistons with a wood block and hammer, but no luck. I have read about heating up the cylinders and then letting them cool before trying the block and hammer again, I might try that next.

I'm trying not to disassembly the engine more than necessary, but is it time for me to pull the crankshaft out and work on the cylinders individually?

Also, could there be something with the flywheel that is preventing me from turning it?

 

[alldodge]

Have you checked the block for cracks? If its cracked no since in going further. Check dip stick oil level, then pour some water in the water jackets and see if it holds, if not look on the block and in the dip stick to see if the level came up.

If all that is good, then start your disassembly, your going to need to rebuild

 

[Fishermark]

Is the outdrive installed? If so, pull it. It might be what is frozen. Otherwise, you have the engine already almost stripped down. I would pull the engine and completely disassemble and evaluate what you have.

 

[Scott Danforth]

I agree, pull the drive.

 

[Kruegs35]

Yeah, the drive is already off and the engine is already pulled. I guess I don't have any excuses to take the rest apart.