1991 88hp engine teardown

[barrie ontario]

i have never done this before so i will be asking lots of questions as i go.
i`v`e removed carbs ,starter,coil flywheel, lower unit linkage etc.
in the beginning i had compression issues and found the top of a piston banged up good and the cylinder scored a bit along with the headed had taken a beating from the broken rings.
first question: is it straight forward as it looks to get the whole block off now from the bottom bolts under the cowling.
second question :to get the cylinders redone do i have to remove the exhaust cover etc.
Third question : the manual says you don`t have to oversize all the pistons is this ok.
Forth question: the top of the head got banged up does it have to be replaced or just cleaned up.
Thanks in advance if any brave soles would like to guide me through this.

 

[bob johnson]

Re: 1991 88hp engine teardown

I ahve heard you want a smooth consistant surface in the head, so you dont have the chance for a hot spot to develop..I took my buddies motor apart and it has parts of steel embedded in the aluminum head....that would be bad to run like that!!!

for the 25-50 dollars for a head...get another...

I just took a seemingly well preserved 1997 motor apart!!!

I broke off two of the small bolts that hold the power head on and the 6 big bolts were a nightmare getting off.....if i didnt have an electric impact gun...id still be there unscrewing them...I am a big strong guy and it was like 1/4 turn at a time with a 2 foot breaker bar at about 200 lbs of torque!....and the threads are like 2" long!!!( and i used a oxy-acet torch to warm the block!!!!!!!)

then the upper mount was corroded to the block... and three of the six bottom crank case housing bolts had to have the heads cut off in my milling machine, because they were so rusted away you could not get a socket on them!

if everything is clean and newish....it is all easy...but if it is old and was near the salt water enviroment..it could be a nightmare


good luck

bob

 

[barrie ontario]

Re: 1991 88hp engine teardown

Thanks Bob, no salt water that i know of, all the bolts i see look good.
i am going to try it this week-end, i do have air and electric impact available.
i`ll let you know.

 

[wilde1j]

Re: 1991 88hp engine teardown

It's perfectly acceptable to only bore the bad holes in an outboard, as long as the others are still within service limits. I would re-ring all, though. I my own motors, I've generally done all holes, so everything is like new and replaced any bearings that were even slightly in question.

 

[barrie ontario]

Re: 1991 88hp engine teardown

Good news it came off easily and yes i was intending to re-ring all of them but since were i am a piston and ring set is about $100 after taxes i was only going to do the oversize piston if i could.
looking at it i guess that exhaust cover does have to come off so they can mount the block in a fixture to hone it at his engine shop, i found a fellow that does this for $20 a hole.
Thank you fellows

 

[barrie ontario]

Re: 1991 88hp engine teardown

Good news it came off easily and yes i was intending to re-ring all of them but since were i am a piston and ring set is about $100 after taxes i was only going to do the oversize piston if i could.
looking at it i guess that exhaust cover does have to come off so they can mount the block in a fixture to hone it at his engine shop, i found a fellow that does this for $20 a hole.
Thank you fellows

 

[wilde1j]

Re: 1991 88hp engine teardown

Follow the OEM shop manual procedures for cleaning the block and re-assembly and you should be fine. I hope the $20 guy has significant experience boring outboard blocks and can tell you the oversize to buy for the bad hole. Make sure rods, bearings and pistons all go back in the same places.

 

[barrie ontario]

Re: 1991 88hp engine teardown

after reading dozens of threads on this site i have decided to do everything that could have caused this I.E. clean carbs , water pump , themostats etc.
this is going to be a take my time project as i get extra cash do it right.
what a great forum. thanks everyone.

 

[emdsapmgr]

Re: 1991 88hp engine teardown

I think you are smart to replace everything. That way you know where you are when you start it back up. Don't forget the 4 water diverters in the powerhead.

 

[barrie ontario]

Re: 1991 88hp engine teardown

I think you are smart to replace everything. That way you know where you are when you start it back up. Don't forget the 4 water diverters in the powerhead.

Yes i seen that in another thread with a picture of them mine are the same they look like squished rubber tubing i guess they could get brittle over time and breakdown i will do that. i am glad you brought that up!

i just got my 5/16 12 point socket for the rod bolts ,also info from another thread.
thanks .
Gary