1995 Evinrude 70 Rebuild Project

[trendsetter240]

Hi guys,

I'm just starting on a rebuild (rebore, pistons, rings, bearings and powerhead gasket set) for my 95 E70ELEO. I've got a few manuals but not one for this particular model. I will be ordering one soon; any suggestions on a good manual? I wasn't that impressed with the Seloc ones I got for my mercs.

Also I'd like to get the motor disassembled soon, probably before I get the manual in the mail. Any tips on things I should or should not do during the teardown proccess?

I've rebuilt a few 2 stroke motorbike engines but never gone this far with an outboard. Any advice would be much appreciated.

Thanks!

 

[tedious]

Re: 1995 Evinrude 70 Rebuild Project

Forget the aftermarket manuals, go OEM: http://www.marineengine.com/parts/p...pe=Service+Manual&Engine=437482&Model=70ELEOR

Tim

 

[trendsetter240]

Re: 1995 Evinrude 70 Rebuild Project

Forget the aftermarket manuals, go OEM: http://www.marineengine.com/parts/p...pe=Service+Manual&Engine=437482&Model=70ELEOR

Tim

Thanks Tim, I'll order a manual from there.

Motor is coming apart, bolt by bolt. Got a quote from the machine shop and parts dealer. Looks like about 900 CDN and lots of my labor to get this thing rebuilt. Add the 200 I paid for the motor and controls and I think I got a pretty good deal!

 

[reeldutch]

Re: 1995 Evinrude 70 Rebuild Project

Before tearing it apart look very close to the engine and find out why you need to rebuild it.

just low compresion doesnt tell you why it happend.

could be lots of things and you dont want to spend all that money and have it happen again because of something is not right like a crancase leak or anything.

whatever it is you have to make sure you fix it so you will feel confident putting this thing back togetter .

is the timing set correctly?
did somebody mess with it?
does it have good spark?
etc etc

the manual wil not tell you this.

 

[trendsetter240]

Re: 1995 Evinrude 70 Rebuild Project

Before tearing it apart look very close to the engine and find out why you need to rebuild it.

Hey reeldutch, yeah that's a very good point. I'm still not 100% sure what caused it but it was something foreign got into the #1 and #2 cylinders. Like a piece of ring or bearing. This caused scoring on the #1 cylinder and lots of pitting on the #2 head.

There was a LOT of carbon buildup inside the cylinders so maybe that caused a ring to stick and then break?

As for the rest of the powerhead, it's in mint condition. Everything looks brand new and the engine ran before I started taking it apart.

Once I get the crankcase open I'll hopefully be able to find what broke. I will post once I do!

 

[trendsetter240]

Re: 1995 Evinrude 70 Rebuild Project

Well, I got my OMC manual and I've got a bit farther on the tear down process.

The powerhead is off and onto my bench. Lower leg has been removed from later servicing. Now I need to remove the flywheel before I can get any further. I don't have a flywheel puller yet though so I am stuck until I get one.

The motor is in very good shape for it's age.

Here are a couple pics.

 

[trendsetter240]

Re: 1995 Evinrude 70 Rebuild Project

Well, I've found the first of what may be a few problems.

The crank has some rust on it and both center main bearings are shot. Ive attached pics of both.

What do you guys think...is this worth fixing?

 

[trendsetter240]

Re: 1995 Evinrude 70 Rebuild Project

UPDATE: I've got the pistons out and removed both center main bearings. Only the upper main bearing was shot.

I cleaned the crank shaft and found that there is some pitting on the journal where the upper center main bearing was. Also there some pitting and rust on the crank above the journal on #2.

The #1 piston had stuck rings and TONS of carbon build up. The rings were not broken. #2 and#3 are intact and not stuck.

SO. Where to go from here... My thoughts for the failure are that the #1 piston rings became stuck from carbon, running the engine like this caused the failure on the center main bearing and the resulting flakes of metal caused the scoring in #1 and the pitting on the upper center main journal.

Anyone else have thoughts or oppinions? All advice is greatly appreciated.

Thank you!

 

[trendsetter240]

Re: 1995 Evinrude 70 Rebuild Project

#1 piston with carbon, stuck rings and lots of damage.

Pitting on upper center main journal.

Rust in #2 crank.

 

[James R]

Re: 1995 Evinrude 70 Rebuild Project

The crankshaft condition is the killer for me. If you add all the costs up you will be better off finding a good used power head.

 

[reeldutch]

Re: 1995 Evinrude 70 Rebuild Project

yep that crank is junk.

question still is how did it get water in it to get it pitted like that?
has it been sitting for a few years in a shed and wasnt put away propper?

even if you find a good crank cheap you still need at leas one new piston all new bearings for your new crank, man i hate to say it i wouldnt do it.
if a crank gos bad thats it..... junk.
safe all the other stuff and find a powerhead.

 

[trendsetter240]

Re: 1995 Evinrude 70 Rebuild Project

yep that crank is junk.

Ouch! Yeah that is what I feared.

I added up all the parts and it is about 1600 for what I need now. That is if I reuse two pistons and all the connecting rods.

question still is how did it get water in it to get it pitted like that?

has it been sitting for a few years in a shed and wasnt put away propper?

I don't know the answer to either of those questions. I inspected the block and water jackets and didn't find any cracks. I know that the PO had the head off and then it sat for a few months.

I guess I will start shopping around for a powerhead. It's a shame because this motor has so many excellent parts. Maybe I'll just part it out on ebay and buy a whole new (used) motor.

No matter what I only paid 200 bucks for this one and the controls and wiring harness are worth more than that. Not to mention the leg which is mint.

Thanks for your advice.

 

[reeldutch]

Re: 1995 Evinrude 70 Rebuild Project

what im trying to say is just look for a powerhead.
even if its blown up you might get a good crank.
dont trow it out just be patiant and keep your eyes open i believe a 60 horse will fit to.
the pitting on the journal is going to kill a bearing.
so dont even think about reusing it .

you dont need a stator carbs all that stuff you got .

just keep looking you will find something.
i wouldnt buy just a crank for a lot of money you will need al bearings and stuff.
what you want to look for is a block that has low compression for dirt cheap or even free and tear it apart.

good luck

 

[bktheking]

Re: 1995 Evinrude 70 Rebuild Project

Have the crank repaired, it will be like new when its finished, used may be throwing your cash away.

http://www.marinecrankshaftinc.com/outboard.html

 

[bkwapisz]

Re: 1995 Evinrude 70 Rebuild Project

Look at it this way: Rebuild what you have and you'll basically have a brand new motor that you know will be done right for much less than buying a brand new motor.

 

[nymack66]

Re: 1995 Evinrude 70 Rebuild Project

I am working on re-building my 1987 140 v4 and ran into a bad crank myself, I found a perfect crank on ebay and and I am on my way this set me back 200.00. In the end its your call I will check ebay or there is a very reputable company in California see on www.screamandfly.com the boys all recommend this company for any crankshaft work ..

 

[trendsetter240]

Re: 1995 Evinrude 70 Rebuild Project

interesting..I didn't know that cranks could be repaired. I'm going to take my block, crank and head into my machine shop this week and see what they can do.

I'd really like to rebuild this motor as it's super clean for it's age. Everything else on the powerhead is in great shape.

 

[reeldutch]

Re: 1995 Evinrude 70 Rebuild Project

crank cannot be repaired.
the reason is they only make one size bearing for that motor.
i dont think a weld and machining it down to spec is a good strong surface for your bearings to roll around at 6000 rpm in.

it has to be so perfectly done or it will fail.
and than you still haver a bad crank and may be a rod trough the block.
find yourself a good crank thats the best way.

 

[bktheking]

Re: 1995 Evinrude 70 Rebuild Project

I disagree that crank cannot be repaired, I know guys that have sent their motorcycle cranks out to be repaired and they come back better than new and they spin 2x faster than a boat crank. It's not like his is split in 2 , it's just a machined surface. Build it back up and re machine it out to spec, if you have the equipment it can be done.

 

[reeldutch]

Re: 1995 Evinrude 70 Rebuild Project

sounds good to me.

please let me know if you send out the crank and have it fixed, buy all new bearings, rebuild the motor for a reasonable price, and have a good running engine.

always having in mind the "fixed" crank when you open her up?