Mercruiser 2.5 1981

[Michigan semidriver]

I'm brand new to the boating world... A truck driver by trade and a mechanic by necessity, I decided to take the plunge and picked up a 1981 rinker with a 120 mercruiser. Before purchase, I studied all post I could regarding these boats and everything about this engine set up.. I got the boat and trailer for 75 bucks.. the boat was a previous restore and and was very impressed with the shape. Transom, stringers floor and hull in impeccable shape... The motor ran but not in 5 years so I knew the undertaking i was embarking on. Having a well set up shop with many rebuilds from cars and semi trucks under my belt, a marine engine repair would be second nature. Boy was I wrong...
My first question is, how in Sam hill do you get the starter out... My research shows 3 bolts; one rear bracket and 2 starter housing bolts. I can get all but the short bolt closest to the side of the boat. There isn't any clearance between the bolt head and flywheel cover. What's the secret to it?
Me second question is, is this boat large enough to go out on lake Michigan? With it being 18 ft open bow, what wave height is considered to much for this boat. Thank you

 

[Scott Danforth]

welcome aboard.

many times, its easier to pull the motor to get to the starter than it is with the motor in the boat.

regarding lake michigan and rough water, depends where you are on the map. I wouldn't go out in the bay with anything more than 7mph winds and a 2' chop. if the wind changes slightly your into 7-10 foot rollers quickly. into lake michigan itself, would depend on the direction of the wind.

my old Avanti probably had 400 hours walleye and perch fishing on the bay.

 

[kenk63]

do you have a pic?, have an 82 stingray with a 470, changed the started a couple months ago, if i remember right, one one bolt i had to loosen it a little, pull the starter a little, loosen the bolt a little, you get the idea, as far as 18ft in lake MI. you`ll have to watch the weather closely, open bow takes on more water than a closed bow, splashing from the waves, I went to lake Erie a few weeks ago, stingray is 19ft, 3 to 4 ft chop, ruff ride, wanted to see if the old girl would stay together, she did

 

[Michigan semidriver]

I decided to pull the motor, took me 15 minutes... Got the starter off and now to decide... Refresh the motor since it's out or do a swap to the 3.0 since I'm finding are a dime a dozen.... Decisions, decisions lol

 

[Scott Danforth]

go 3.0, even your 2.5 head will bolt on if needed

Just remember, 1990 and older or 1991 and newer. 1991 was first year of 1-piece rear seal.