Early 80s Evinrude 35hp Rebuild (Edited Tittle)

[squirly]

Hello everyone!

Have a couple of quick question regarding a crankcase. Im working on an early 80s Evinrude 35hp block, replacing all the gaskets and seal etc. Ive sprayed some wd40 inside the crankcase last night and this morning I've noticed the wd40 seeping out from the side of the crankcase (the block is on its side on the bench). Does this mean i really should open up the crankcase and reseal it, or is it just because of the penetrating properties of wd40 that it manages to seep through the case?

The reason for the initial rebuild was a rusty top spark plug, the result of a worn gasket in the exhaust buffer plate. After taking off the bypass cover i noticed some specs of rust on the crankshaft also. Not much, but a few specs here and there. What are the chances of rust damage to rollers/bearings inside? I pulled the lower seal and looked at the lower bearing and it looked perfect. I should also mention that the previous owner had bored out the cylinders and replaced pistons, which makes me think the crankcase/shaft mustve been rebuilt at the same time. Im by no means a specialist but the oversized wiseco pistons look in very good condition and don't look like they've been used much before the exhaust gasket failed and the engine was put away.

Question is, shall i go for a full rebuild and check the crankshaft while I'm almost there anyways, or should i reassemble and hope for the best? What parts will definitely need replacing once i open up the crankcase and get to check the shaft? I have another 35 block, and also a 78 20hp so i was thinking not to rebuild and just replace the block when this one gives up. But id like some advice to help me make up my mind.

Thanks in advance!

 

[gm280]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

If you presently have the block (power head unit) off the lower section and laying on your bench, I would certainly open it up and inspect everything. It is easier to do now and be sure then assembly it back together and fine a problem after starting it up. But that is just my opinion. If you do open up the block and disassembly anything else, take plenty of pictures AND mark the pistons, rods and bearing as to how they were removed and the directions they go back. You may think you will remember, but trust me, you won't. So mark everything to get them back in their proper places and directions... It only takes a little more time. This way you will know for certain the real condition of everything... JMHO!

 

[racerone]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Take it apart for inspection.----The 2 halves of the block are precision machined and must fit perfectly.--All to often dirt / old sealer / bumps and bruises are not cleaned up properly.--Some times bearings are not properly located on the dowels.---This will result in crankcase leaks and poor idle qualities.---The correct sealer must be used on assembly with a 1/16" bead.--Most of that sealer should squeeze out for a metal to metal fit.

 

[squirly]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Thank you for the quick replies. Thats pretty much what i was thinking but kind of wanted someone to tell me she will be ok as she is... Im a bit nervous, the only other crank I've opened up was an old Seagull and she was rather basic. Will make sure ill take plenty of photos, i do have a seloc manual which should help me along as well. So what bits will i definitely need to replace? Expendables like seals and grommets are hard to come by over here in UK so will need to make an order from one of the US suppliers and it takes absolutely ages to get delivered.

Ah, one more question, does the flywheel need to be removed in order to open the crankcase? That was the most annoying part of the 20hp saga and drove me up the wall for a week, so i would much rather not get involved with it if i don't have to. Manual says to remove the flywheel... But it also says that if the drive shaft comes out of the lower unit it would require a full rebuilt to get it aligned again, however in my experience and from what I've managed to find on iboats it slides back in just fine. So what is it to be?

 

[racerone]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Powerhead must be removed from exhaust housing.-----Flywheel must be removed , no other way around it.--Not sure what anybody means by saying that the lower unit needs a full rebuild when the shaft comes out.----Shaft can be re-installed if you are blind in one eye and can not see with the other !

 

[squirly]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Ok, thanks! Going to try get the flywheel off and see how i get on. The drive shaft statement is in my manual. Rebuilt the lower unit on the 20 just because i pulled out the driveshaft and the manual said id have to rebuild to realign, and only after opening it up I've realised how unnecessary this was.

"ADVICE
If the only work to be performed is service of the water pump, be extremely CAREFUL to prevent the driveshaft from being pulled up and free of the pinion gear in the lower unit. NEVER carry the lower unit by the driveshaft or by the shift rod. If the shaft should be released from the pinion, the lower unit MUST be disassembled to align the pinion gear and driveshaft, then the driveshaft installed."

Seloc manuals for ya!

 

[gm280]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Ok, thanks! Going to try get the flywheel off and see how i get on. The drive shaft statement is in my manual. Rebuilt the lower unit on the 20 just because i pulled out the driveshaft and the manual said id have to rebuild to realign, and only after opening it up I've realised how unnecessary this was.

"ADVICE
If the only work to be performed is service of the water pump, be extremely CAREFUL to prevent the driveshaft from being pulled up and free of the pinion gear in the lower unit. NEVER carry the lower unit by the driveshaft or by the shift rod. If the shaft should be released from the pinion, the lower unit MUST be disassembled to align the pinion gear and driveshaft, then the driveshaft installed."

Seloc manuals for ya!

Let me make one very good suggestion, before you get too far involved, buy a factory, year, HP and model specific shop manual for your engine. Those after market manuals are too general to have much quality info about how your specific engine is disassembled and reassembled again. The information in a factory specific manual is by far the best in the world...believe me... The shop manual will walk you step by step through every little issue with your engine with many pictures, charts, and instructions. For a first timer, like I think you stated, it is a must!

 

[squirly]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Thanks for the good advice gm! I have no doubt it would make the process a lot easier and i wish i had one, or more like four... Unfortunately both 35s are a mishmash of different 35s from various years. Ones blue and the other is golden. The blue one has a late 70s block, on a later 80s midsection and gearbox with the shift linkage in the lower unit. And the golden one is an early 80s block on a late 70s midsection, with the shift linkage in the midsection. So id have to get at least 2 different manuals to cover each. And considering i cant pinpoint the exact year of any single part, i don't think i should cash out on two potentially random manuals and put the money towards parts instead. Ive tried to find them in a digital format as this seloc manual, but i think model specific workshop manuals only come in paper copies, and only from your side of the pond it seems!

 

[squirly]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Ah i bit the bullet and ordered a factory manual from feabay, so i shall see it in about 3 weeks time... I cant let it sit for 3 weeks on my bench though, so I've made a start and got the flywheel and the plate assy off. Im now trying to work out a way to punch out the guide pin. It said to use a punch and literally punch it out, but i don't seem to be able to get a good angle on it and its not budging. Is there a technique or a tool to be used?

 

[boobie]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

The making of that tool is also in the service manual.

 

[Bosunsmate]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

The first motor i rebuilt was a early 80s 35. I didnt use any special tools, i put it back together without a torque wrench too. I would suggest getting one of them though.
As suggested above take heaps of photos from all different angles of every step,
If yours was the same as mine the cylinders have a nice sloping groove on them so the rings gradually get pushed into the cylinder, you dont need to hold them/use a ring compressor.
Ask what seal gel you should use and you will get a lot of different answers.
I use permatex aviation form a gasket, its about $5 and is easy to apply.

 

[squirly]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Thanks Bosunsmate! Ive been using hylomar blue as a gasket sealant, but think for the crankcase i will order some Gel Seal II or the Permatex stuff... Ive got most basic tools and have access to more advance equipment, but i did invest in a torque wrench already.

Boobie i figured the pin extraction tool would be in the service manual, but like i said it will be at least 3 weeks till i have my hands on one and was looking for a bit more info on it... Does the pin have to come out first, before any other bolts on the case? Or can i take the bolts out and try to wiggle the pin out afterwards?

 

[racerone]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

The pin is tapered and should be taken out before seperating the cases.-----Good call on using the gel seal.-----If you use a sealer with too much " filler " in it then it may not squeeze out properly.---You want most of the 1/16" bead to squeeze out of the joint to get metal to metal contact..

 

[Bosunsmate]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

If i remember rightly and its the pin im thinking of i just used a flat blunt nail as a drift to knock it out from behind and then I pulled it out with pliers.
If you cant do that then its not the pin im thinking of, im pretty sure im thinking of ones which kept the crankcase halves lined up and were tapered as racerone has said.
With bolts and pins out i gently knock the case apart with a rubber mallet to separate the seal coating thats left, i lightly tap part of the crankcase where i can start forcing it apart by knocking one half in one direction and holding the other and it will then split.

Im away for two days, but post a photo of this pin if you a still stuck, no way would i wait three weeks either, its only a tapered pin about 3/5 of an inch in length in my recall.

 

[racerone]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

The pin drives out fairly easily, it is tapered after all.---Most of the times it ends up on the floor after a couple of taps.---If you " mushroom " the end of it it will be tough to get out.------It is drven from the " sparkplug end " of the motor towards where the carburetor would be.

 

[Bosunsmate]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

The pin drives out fairly easily, it is tapered after all.---Most of the times it ends up on the floor after a couple of taps.---If you " mushroom " the end of it it will be tough to get out.------It is drven from the " sparkplug end " of the motor towards where the carburetor would be.

Yep thats it, just tap it out in that direction towards carb, dont hit the carb end of it as thats the wrong direction and will mushroom as said above^^

 

[squirly]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Thank you both so much! Just managed to get it out, had to twist and pull on it with vice grips. I suspect its because its been painted over and twisting it broke the seal. Think ill leave it for tonight and open her up tomorrow. Will post the findings with some photos! Thanks again!

 

[squirly]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

So... Bad news. The crank is indeed pitted. Haven't got the piston rods off yet as need to order the 5/16 thin walled bi hex socket, but the surface under the centre bearing is rough and i can feel the dings with my nail. Feel rather gutted but its not the end of the world, is it? Can anyone tell me a way to pinpoint the exact year of the model by looking up a specific part number? Because going by part numbers, the cranks for different years are different. Heres what i have so far:

Bypass Cover 326314 1982
Head 327672 1982
inner exhaust 326263 1982-2005
outter exhaust cover 326713 1984?
block 391058 d1 1981-1986
Flywheel 582434/5 1983-1984

Some of those numbers don't show up in a parts catalogue, like the block and the exhaust cover, but I've managed to find their years through fleabay. So i have a 1978 20hp Johnson that I'm prepared to tear down for parts, provided the crank will fit. If it won't, i have another 35hp, but of unknown year. What are the chances that either of those cranks will fit??

 

[racerone]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

The first thing to check in interchangeability is the driveshaft spline on the crankshaft.-There were a few changes in the early years.

 

[squirly]

Re: Evinrude Crankcase Leak

Re: Evinrude Crankcase Leak

Im not 100% sure about the 20hp, but the drive shafts on both older and newer 35hp gearboxes I've got here have 14 splines and look identical except the newer on has a dimple at the top of the shaft and the older doesn't. And i cant find the part number on the crankshaft, its suppose to be on the tapered end near the woodruff key, correct?