1987 Evinrude 70HP VRO E70ELCUR Repair

[mngopher22]

I just bought a boat very cheaply with a 1987 Evinrude 70HP VRO that was in non working condition.

The head gasket was blown and is shown in the images below.
I took the lower unit off and checked the water pumped. The water pump is also blown.
I removed the thermostat from the head and that is well .... just look at the attached images below.

I am looking at repairing this engine. The first thing that I have done is ordered a new head gasket. That will arrive this Saturday. Once I receive it, I will do a compression check. After reading the forums here, I believe I am going to be looking for compression readings above 100 and all three cylinders to be within 5% of each other. Please correct me if this is wrong, I would appreciate your input.

Once I verify that the engine has adequate compression, I will go ahead and order the water pump repair kit and a new thermostat. I have also read that I need to relocate the tell tale. I have read that service bulletin 2276 and am comfortable with what I need to do. Could you guys confirm the part number for the water pump repair kit and thermostat. I believe I need the OMC Water Pump Kit 432955. Is this correct?

The o ring at the top of the drive shaft in the lower unit is broken, which part will I need for this?

Any general guidance, comments, or concerns is greatly appreciated! I will keep going over the forums and see if I can track down any more answers.

 

[mngopher22]

Photos of thermostat

 

[mngopher22]

Photos of water pump and lower unit.
Note that the o ring seal is broken on the drive shaft. What is the part number for the o ring that goes on top of the drive shaft? I can't see to find it in the part diagram on iboat.

 

[flyingscott]

What do the cylinders look like?

 

[racerone]

Typical of a water pump on a " new to you motor "----There are those sellers who will fire up a motor at the end of the driveway to demonstrate that the motor runs.----No water needed because it will only run for 10 seconds and the motor will not overheat.-----That pump was run DRY !!

 

[mngopher22]

Photos of cylinder walls attached. I have 0 experience telling if these are any good, but what i will say is that I ran my finger over the areas that look worn and it all feels smooth. That being i said, i would greatly appreciate your input.

 

[flyingscott]

That is not good. Do a compression test as soon as it is all together.

 

[racerone]

Might as well plan the rebuild now.------That motor will not run properly with cylinder walls / pistons in that shape.

 

[mngopher22]

Head gasket arrives tomorrow. I have in my notes 18-20 ft-lbs torque for head bolts. Is that correct? and is there an intermediate tightening torque for these?

 

[mngopher22]

I checked compression on all three cylinders. They all are about 80 PSI.
I am currently investigating the rebuild process. I have come up with some options and I would appreciate any input from you all.

Options

1) Complete rebuild myself. Buy the service manual. Take apart engine, and asses damage to cylinders, cylinder walls, cam, head, and block . Send block for honing/boring. Get block rebuild kit, carb rebuild kit. Rebuild block, rebuild carbs, assemble. Do technical service builiten to relocate tell-tale to top of exhaust body.

2) send power block to boatpartsstore and have them rebuild power block, I would get back a good power block, put back on carbs, electronics etc. Has anyone used this company? https://www.boatpartstore.com/powerhead.asp. are they any good?

3) buy used but working power head on eBay and install

4) buy rebuilt motor complete with install

5) buy new

 

[racerone]

No surprise here.------I would take a crack at rebuilding it yourself.----Then again if you can solve this with an unlimited budget you do not have problems.-----A new motor with warranty is a good option !!

 

[Klink]

The O-ring for the top of the drive shaft is #58 just above the water pump plastic cover in the parts diagram it is # 0326649. ​

 

[mngopher22]

No surprise here.------I would take a crack at rebuilding it yourself.----Then again if you can solve this with an unlimited budget you do not have problems.-----A new motor with warranty is a good option !!

I am thinking this is the route I am going to go. I have a close family member who has a lot of experience working on car motors. I believe his experience is all we will need to do this. Do you have suggestions for best place (read not cheapest) to purchase rebuild kit?

 

[racerone]

If your " car mechanic " runs into things he may not have seen before he should stop and ask questions.-----Hammer in most cases stays in the tool box.

 

[mngopher22]

If your " car mechanic " runs into things he may not have seen before he should stop and ask questions.-----Hammer in most cases stays in the tool box.

Where should I buy my parts for the rebuild? kit on eBay? iboats? Crowley? boat parts store, anywhere else? suggestions?

I am down to either 1) completely rebuild myself or 2) send to boat parts store for power block

 

[racerone]

Take it apart first to see what you need first.------Be sad to buy pistons / rings gaskets / bearings and then realize you need BIG $$ crankshaft / rods.-----Or realize it was rebored once already !!

 

[mngopher22]

Take it apart first to see what you need first.------Be sad to buy pistons / rings gaskets / bearings and then realize you need BIG $$ crankshaft / rods.-----Or realize it was rebored once already !!

It was rebuilt in 2000 and bored to 0.002. Can I do 0.003? If not, can I re-sleeve?

 

[racerone]

That would be 0.020 " and first you need to find a shop that will want to bore out that 0.010"-------Yes the sleeves can be removed on those.

 

[Klink]

Where should I buy my parts for the rebuild? kit on eBay? iboats? Crowley? boat parts store, anywhere else? suggestions?

I am down to either 1) completely rebuild myself or 2) send to boat parts store for power block

I'd first try it like it is, 80lbs in each cylinder is low, but can work. Run it for a while to see if any other bad things show themselves.

If you eventually conclude that it is OK to go the route of rebuilding, I'd go with original Evinrude pistons and rings, and Sierra if they are 1/2 the price.

 

[Faztbullet]

What you see damaged is from the bridged port exhaust,when it overheated the bridge expanded ad scuff the exhaust side of piston. You will need to bore next size bigger and modify bridge. See it all the time.