I/Os For Dummies

[Cherokee-Runabout]

So... after selling my 1977 Lund bowrider (70 hp Johnson) at the end of last summer I was left boatless (save the yaks and the canoe). I bought a small skiff that I use for fishing and power it with a 6hp Tohatsu. My fiance kept on me and I knew the only way to make her happy was to get something larger that would hold more than one or two people. That led us to purchasing a 1985 Sting Ray cuddy with a 190 Mercruiser (It was affordable) a few days ago. For someone that has never run an I/O what are things that I should be on the look out for? In my limited research I have learned the importance of blower operation before starting (and some say when idling others have said that motor air flow will exhaust fumes when idling??), checking fluids before each use, and checking under motor cover for any fuel or fumes. If anyone has any other advice or can point me in the direction of a thread, video or article that goes over the basics it would be greatly appreciated!

 

[Scott Danforth]

on a 34 year old boat, hopefully you inspected the hull/stringers/deck/transom

with any new to you boat, do all the maintenance

• new raw water pump
• new gimbal bearing and bellows
• alignment
• gear oil change
• engine oil and filter change
• plugs/cap/rotor/wires

hit the stickies at the top of the mercruiser forum for maintenance tips

 

[Cherokee-Runabout]

Thanks for the input Scott. The seller (reputable and trustworthy) did an inspection of hull and motor. Everything was found to be sound and in good condition.

 

[KJM]

on a 34 year old boat, hopefully you inspected the hull/stringers/deck/transom

with any new to you boat, do all the maintenance

• new raw water pump
• new gimbal bearing and bellows
• alignment
• gear oil change
• engine oil and filter change
• plugs/cap/rotor/wires

hit the stickies at the top of the mercruiser forum for maintenance tips

why would you do all that if the boat wasn't giving trouble? if she is not overheating why change the raw water pump? if the bearing isn't "growling" and noisy and the bellows looked fine, i wouldn't think about taking the drive off until i had a good reason to. igition components change on a boat that runs fine? i'm far from any expert but i;d think if it ain't broke don't fix it. i would change the gear oil and engine oil and filter at the end of the season if they looked ok now. otherwise and most importantly, don't forget to drain the water out of the engine, mannifold and riser before first frost. it don;t automatically drain out when taken out of water like an outboard and if it freezes inside the engine tour done.

 

[Scott Danforth]

you must assume the prior owner did not do any maintenance before selling the boat to you.

its not repair, its preventative maintenance

the OP asked what needs to be checked, so I pointed out what needs to be checked.

because the impeller gets changed every few years.
the gimbal bearing, bellows and alignment inspection is every year - read your service manual. most likely you will discover issues. failure to check alignment will kill your coupling.
gear oil change is every year.
engine oil change is every years
ignition system because the prior owner didnt do any maintenance

I didnt even mention the trailer, etc.

however KJM its your boat, do as you want with your boat. I prefer to do all the maintenance to make sure its done, because a 25 mile tow is $1200 and a half a day of maintenance is cheap compared to the wife yelling at you for the 3-4 hours your being towed in.

 

[Cherokee-Runabout]

As of right now everything checked out during inspection. I was planning on changing lower oil and impellor before the frost sets in. Is the lower unit maintenance similar process to outboard? I haven't yet looked at a manual as I haven't even picked up the boat yet. Do the generic manuals work fine or should I try to find mercruiser specific? Also unfamiliar with how to drain manifold and riser I am decently mechanically inclined, and have a few small repairs on outboards under my belt ( water pumps, fuel pumps, carb rebuilds, coils, points, realigned pinon gears, winterization, etc...) But all of this was performed on outboard 70hp or less .

I respect that both of you have varying philosophies and I'm sure that mine will vary from either of yours. Scott the mercruiser sticky you have directed me to seems very promising and I have only skimmed the surface. Like I said not my first boat so I know about structural integrity and trailer maintenance just looking for anything that explains basic differences in operation, things to look out for, things to watch, warning signs, etc... And once again thanks for the input!

 

[Scott Danforth]

lower unit service is like an outboard. so is the impeller service

pulling the drive for the annual inspection takes only about 20 minutes

draining the block and manifolds will take about 20 minutes, including pulling the two hoses (large hose from water pump and hose between power steering cooler and thermostat housing)