86' Evinrude 90hp rebuild

[Dennischaves]

I have a 86' Evinrude 90hp vro
the motor has a piston that broke into pieces
(I dont know why this happend I got the motor like this)
The head was off when I got it and theres a little rust in the cylinder
How hard is it to rebuild one of these and what should I look for before I start the rebuild to see if its worth rebuilding
Is there a repair manuel that will walk me step by step
I have done autobody for over 25 years
I do a lot of mechanical work also when its collision related. I have even done a few clutches on cars and put piston and rings on a dirtbike when i was younger so I am pretty
crafty when it comes to turning wrenches
any help would be appreciated
dennis

 

[Baylinerchuck]

I guess it depends on how damaged the cylinder is, and/or what caused it to explode. You can still purchase manufacturer shop manuals for these outboards. They are a tad pricey, but will have a ton of information in them. Stay away from the Seloc manuals for this type of in depth repair. The 90 hp J/E is a really good motor in my opinion. I really like these older 2 strokes. Parts are still readily available.

 

[boobie]

If you get any service manuals, get the OMC Factory Service manual. Stay away from Seloc or Clinton.

 

[ondarvr]

Those motors have a habit of breaking pistons, it's fairly common.

 

[ezmobee]

http://www.outboardbooks.com/ has your OEM service manual. They are pricey but they are VERY good. I checked ebay where I can usually find one and didn't see one for an '86 90. Here's one for an '87 which I assume to be the same but I'd make sure http://www.ebay.com/itm/1987-Evinru...ash=item5d6ba69090:g:gIUAAOSwEzxYRZ1B&vxp=mtr

 

[racerone]

87 manual is the same.----Once properly rebuilt with 4 new O/S pistons / rings it will be a sweet running motor.

 

[Bosunsmate]

Easy to repair, if not a salty, the hardest thing is getting the powerhead off the leg if its a salty, the bolts seize up.
You do need a manual just to make sure you cover a couple of little important things such as making sure oil passages are in the right place and torque settings etc. Online ones a fine and free http://boatinfo.no/lib/library.html
Be sure to do the water pump and change out the gear oil in the leg.
You can aslo get underway by planing the heads flat using sandpaper on glass or a mirror and moving the head in a figure 8 until all areas are shiny

 

[johnson89]

I did my 89 90hp about 2 years ago 1100.00 give or take,i had a busted ring....... the motor is running like a champ and is my first rebuild of a outboard..... do lots of reading before taking the motor apart

 

[interalian]

I did my xflow 90 to 140 parts combo last spring for about the same cost. Farmed out the machine work but did all the other work myself. Not hard, but not quick. It's a bit like finishing drywall - the pros make it look easy and fast when it's far from that as a DIY.

 

[Dennischaves]

If I do replace the pistons is that going to mess with the timing and how do I look for the underlying problem that caused the piston to meltdown?
Also do the carbs need to be readjusted when im done?

 

[racerone]

As long as you work carefully timing will not change.--------Ditto for carburetors.-----Worry about that after you have the engine back together.

 

[interalian]

A picture of the broken piston? You do need to figure out why it failed. Usually an overheat condition either from lean running (plugged jet on carb) or cooling. Which cylinder?

Timing will be very close provided you don't turn any of the linkages you remove from the block. When you're finished, check base timing using the Joe Reeves method - sticky at top of forum.

 

[Dennischaves]

what linkages on the block
that would affect timing?

 

[racerone]

The maximum timing advance has a stop on the block / intake manifold ( black rubber cap on it ) and if that has never been touched the timing will be correct after re-assembly of the motor.----Best to rebuild the motor first and if you are still confused then, ask more questions.

 

[Dennischaves]

Thanks everyone
any recomendations where to get the rebuild kit?
I see them on ebay,amazon and a few other sellers
I dont want to end up with crappy parts

 

[interalian]

There's also the threaded adjustment where the throttle cam is connected to the throttle arm.

I bought my parts from a dealer since I'm in Canada (so many US vendors are clueless about shipping to Canada), and prices were comparable. I have very little faith in ebay or amazon for parts like this, but others will surely disagree.

 

[Bosunsmate]

Dont stress about timing, its easy to adjust and check and you will want to do that too to make sure that too advanced timing didnt burn up your piston.
Ive never had any crappy parts but i get all mine sierra brand at reasonable price so have no need to try something else.

 

[Faztbullet]

Don't buy any parts till you get it apart and can see all the damage and determine the cause..

 

[Dennischaves]

I got lucky today
I got a 1990 evinrude 115 power head that I can turn the flywheel so it's not seized
How many of the parts are interchangable with1986 evinrude 90hp I'd like to use the 115 power head
And what's the first thing I should do to check if the power head is actually good
I know it hasn't been run in a few years but supposedly ran strong