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1982 Johnson 90

T

thawcko

Member
"Well got it running great aft

"Well got it running great after sitting for 3 years.. Went out today and it ran super... On the way in started to bogg... Made it back to the dock loaded it up took it home.. Removed the plugs and found one was squished.. removed the head to find the top of the piston all dinged up... The walls seem fine just the top of the piston and the cone.. To replace the piston, do I have to remove the whole block or is there an easier way??? I have a feeling I know the answer... but HELP... please..."
 
"Also, once I get this torn ap

"Also, once I get this torn apart, what is my best option if the walls are scored? Can I do one oversized piston? or do I need to do em all? Or should I have the one jug sleeved??? Plan on replacing all the rings while I have it torn down..."
 
"You seem to be in for a major

"You seem to be in for a major owerhaul! As for piston oversize - yes you may do only one if needed, and yes you will have to take it all apart! If you are not experienced and have the right tools,this is not a job I would recommend. When doing the job, have your thermostats and waterpump serviced/replaced at the same time. The thermostats may be a lot easier to access when the powerhead is off! However the job is wasted if you do not find the reason for the breakdown. To me it sounds like a 'lean-burning' dammage caused by lack of fuel to the dammaged cylinder, or water intrusion causing too high combustion temp."
 
"Well I just replaced the wate

"Well I just replaced the water pump and thermostats this week... I think there was a leak at one of the carbs ultimatly not feeding gas to that cylinder, found gas was leaking from the carb when I was inspecting it... I have rebuilt car motors and Jetski motors, so figure I should be up to the task.. Hell may as well try, I figure the motor is not worth paying someone to do it.. But I will be asking many questions.. by the way would it be better to go with the oversized piston or have it sleaved???"
 
"Go with the oversized piston.

"Go with the oversized piston. The bigger bore would make no difference, and the oversized piston are normally wheigt balanced to the standard piston size wheight. Next time You may have to re-sleeve it! However watch out for the sealing surface ot the cylinder top. Check that the aluminum cast is covering the sleeve all the way up and no cracks leaking water in between the sleeve and aluminum."
 
"Ok started to tear it down. M

"Ok started to tear it down. My question is, do I need to remove the intake? Are there bolts that are only accessable if I remove the intake? Thanks..."
 
"You will be in for a long day

"You will be in for a long day, my time is past midnight!
Start by disconnecting all externa components like carbs, starter, coils etc.
Remove the rear lower cover under the cowling:screws down from inside the cowling.
remove the lover forward that goes around the steering shaft.
Remoove the bolts holding the power head and the nuts. The middle bolt on port side may be rather stuck, try to heat with propane burner. If everything fails, take a 8mm drill and drill it off 10mm under the powerhead flange!Sounds brutal, but works! Hhen You are sure all screws and nuts, hooses and cables are off, lift off the powerhead!
Off with the fly wheel, the rest of ignition, the heads, the airintake.
Out with the screws for upper and lower cranck shaft bearing houses.
Knock out the dowel pins that aligns the cranck case to the cylinder, split the cranck case. Small outer screws first.
Split the con-rod big ends, watch out for the bearings and be sure that you get them correctly matced after you have pushed the rods and pistons out of the cylinder!
Any more questions?
Go to work, enjoy Your day, I'll enjoy my night, it is allready past midnight where I am!"
 
"Thank you for the info, I too

"Thank you for the info, I took all the componets off , and a few other bolts and stuff, will continue to tear it down later when it cools down a bit, hot here in south Florida, going Jet sking for a few hours.. Again thank you for the help. Sure I will be asking many more questions..."
 
"Had a great time out on the s

"Had a great time out on the ski.. Enjoyed it so much went thru 3 tanks and didnt get home till after dark, so No boat repairs went on... LOL Will hop on it today.. So watch for all my questions, and Thank you for giving me some of your time..."
 
Ok Got a Question... From unde

Ok Got a Question... From underneath I removed the 3 long bolts on each side The two nuts in the back... Am I missing anything from under? Before I try to lift?? I see three nuts under right abouve the mount to the boat.. Do those hold it down also? the middle one looks to far forward to be into the powerhead.. They look in real bad shape so I ask before I bust my cookies trying to remove em...
 
"At least two must go, honestl

"At least two must go, honestly not quite sure about the third. When you try to lift, note that the powerhead may be rather 'glued' to the gasket. Try to carefuly loosen it with a crow-bar or similar under the cylinders. Put a piece of wood between to protect the cowling and cylinder."
 
"Thanks for the reply, would t

"Thanks for the reply, would the hard copy manual be more detailed then The online version I purchased???"
 
The on-line are normally copie

The on-line are normally copies of the hard copy! However the hard copies are more convenient to bring around when working and photos are normally better.
 
"reason I as, is the online co

"reason I as, is the online copy dont have much to it, like the wire digram if you click on wire digram it just shows the discription, with no words no pictures nothing, and is the same for alot of things.. Just blank empty pages.. The manual has a couple of pictures of things with no information no directions nothing, these are pictures I could view anyplace online..."
 
"The most important is that Yo

"The most important is that You get the torques right. Wireing goes colour matched, which screws go where you may just put them in small boxes and mark them. As I earlier said, do not mix the con rod big ends and note how the pistons are in the cylinders before you take them out. Write cyl number with a marker pen on the upper surface of the con rod.
Finally be sure to you have a good description of how to synchronize the engine after assembly."
 
"I have the power head off, re

"I have the power head off, removed the intake, now I am about to remove the flywheel, but dont have the correct socket, have an 1 1/2 and a 1 1/4 first too big 2nd to small so off to the store, must be a 1 3/8 I hope... The reason I needed the wire diagram, is there is a whire running from the red on the block that was mounted on the power head ran under the flywheel and had a but connector on it but attached to nothing, so wanted to know where it goes..."
 
"Sorry, I do not have them in

"Sorry, I do not have them in my memory!
Try the dealer where you by new OZ piston and gasket kit. You even ned the following:
Gel Seal - for the cranck case
Sealing Compound - for gaskets and screws.(Someone may come up with other brands and products, however after testing a lot I still found the above mentioned the best)
They are original OMC products.
As for pistons it depends how much You need to take out of the cylinder. Pistons are available for that engine in both .020 and .030
Even gasket kit I preferr the original one. Have had some bad experiences with Sierra, their 'paper' gaskets are thin and sluggish."
 
Is it an original wire from th

Is it an original wire from the harness?
There is one going from the regulator to the starting solenoid. Close to the solenoid at the rear it should be a black or red rubber fuse holder. May be that is the one.
 
"It runs from the block that h

"It runs from the block that has like 5 terminals there is like 2 yellows a red and 2 other colors I cant make out, have a bit of a color problem...there are two red whire on the red terminal and one goes to nothing right now... The block is on the starboard side and runs under the flywheel to the port side and was just tucked under near the starter but is not from the starter..."
 
I just replaced my flywheel an

I just replaced my flywheel and it turned out to be 1 5/16.
 
"Also, I used a 5/16 12 point

"Also, I used a 5/16 12 point socket to remove the rod bolts off the rods and other bolts in the crank case. Good Luck, Ned"
 
"The wire is probably the B&#4

"The wire is probably the B+ charge wire comming from the terminal and going to starter relay B+.
On the terminal block you have 2 yellow from the stator, 2 yellow from the regulator (one with a grey stripe), 1 red from the regulator, one grey to the harness (tach), one red going to the starter solenoid B+."
 
"Every thing on the boat was w

"Every thing on the boat was working with this not attached... but I will look closer when I start to reasemble.. Got another question, do you know where I can get a star socket that is thin walled enough to remove the bolts on the rods I have star sockets but guess not thin walled enough and went try to buy one but seems they are all same as mine... Any Ideas where to get one?/ dont know why they didnt make enough room for a regular star socket... Thanks..."
 
Oh and where should I order a

Oh and where should I order a new piston from?? and figure I should atleast replace the 3 other rings.. Or is that not a good idea??
 
"I got my socket (3/8 driv

"I got my socket (3/8 drive) at NAPA auto parts, Napa brand part no. NB1210. Worked good for me. Look online for your parts, they were way cheaper, even with shipping, than local dealers around here. I agree, replace the other rings. Ned"
 
"I used the 'original'

"I used the 'original' from the OMC tools catalog. It needs to be of hardned steel!
You may use Sierra piston and rings. Changing all would be sensible. Note that OD pistons are normally delivered complete with rings, Sierra even incudes bolt, and bearings if I remeber correct. Do You have an Evinrude/ Johnson dealer in the vicinity that is aproachable?
As for 'everything working' did you check the charging?"
 
"Chris:
Taking the night, wil

"Chris:
Taking the night, will be back tomorrow, however Ned seems to be watching out!
Do not order any parts until you have the complete picture of the repir cost!
}"
 
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