Lower unit crack

[reelmess]

I picked up an '82 9.9hp Evinrude at a yard sale cheap, it runs fine, pumps water and starts with just a light tug.
It was super cheap because the guy said he left the thing out over the winter and it froze, there's a huge crack in the lower unit on the port side.
The gear oil is fine, not new, but no water, it starts and runs fine, runs fine in the water, but has only 105/106 PSI compression cold. I did a decarb on it to get the compression readings I have now, it read only 94/99 when I first got it.

Should I weld up the crack, reseal the lower and call it a day or toss it and find another lower?

Or, JB weld it and hope for the best?

 

[kodibass]

Re: Lower unit crack

I think the crack is in your forward water drain compartment, the reason it froze & cracked is because the drain hole below the crack is plugged full of corrosion & the water could not drain--froze and cracked, this compartment is narrow and deep, when it gets plugged you have to take a pic etc. and dig all of the crud out so it can drain out the hole. I have seen where some have drilled a hole about a inch or 2 above the factory hole as a short cut. If it were mine I would dig the drain open drill a hole at each end of the crack so as to not get any larger, prep and JB weld prime & paint. best of luck

 

[gm280]

Re: Lower unit crack

It is quite hard to weld up aluminum like that (being cast) and I would do what kodibass suggested instead. I had a lower foot plate welded back on but the welder (was a very good and well educated/experienced pro) told me that it was very hard to get it to weld because of the pores poping when heated up. So I'd skip with the actual welding and do the JB weld stuff for starters. If that doesn't work out, then consider actual welding later on. As far as the compresion goes, it is on the edge but if you can get it to run and will work for your needs, I'd skip reringing/boring that as well...JMHO!

 

[HighTrim]

Re: Lower unit crack

It can be TIG welded with Argon. ONe of the best ways.

However, not into the gear assembly, so as stated above, cheaper to JB Weld it and be done with it. I have a very long drill bit that I bore out the drainage compartments with whenever I have a gearcase off.

 

[classiccat]

Re: Lower unit crack

nice find! right now the crack is benign. I don't know the risk/probability of that crack creeping into the business parts of the gearcase. A preventative measure would be to drill a small hole at each end of the crack before filling with JB.

Also, I think those compression readings are fine; that's a pull start motor correct?

 

[boobie]

Re: Lower unit crack

Make sure the drain hole is open for that part of th L/U and JB Weld it.

 

[reelmess]

Re: Lower unit crack

I figured that I'd just stick a small plastic tube in the drain hole before JB Welding it.

I have had luck with alumaweld in the past too but I don't care to heat this thing up enough to have to reseal it, it don't leak now and I don't care to have to deal with it. If it were leaking I'd probably just find another lower, or buy a new housing.
What I did was mask off the surrounding area and used a spot blaster to sand blast around the crack so the epoxy can really adhere to it.

The way I see it, the motor won't be used for big lakes or the river, just for a few 9.9hp limited lakes here, and maybe for crabbing.
I've got a super light 14' Alumacraft that this should do well on. I was going to throw a new impeller in it but the whole w/p looks new, so I'll put the new impeller on the shelf till next year.

Do my compression readings sound normal for one of these?

 

[boobie]

Re: Lower unit crack

Yes........

 

[reelmess]

Re: Lower unit crack

nice find! right now the crack is benign. I don't know the risk/probability of that crack creeping into the business parts of the gearcase. A preventative measure would be to drill a small hole at each end of the crack before filling with JB.

Also, I think those compression readings are fine; that's a pull start motor correct?

I will drill the ends of the crack, plus probably try to sand blast the area to get good adhesion on the JB Weld.
Its a rope start model no electric start.
Does the compression vary between manual and electric start motors?

When I checked the compression, I basically just held the throttle open, removed both plugs, and pulled the recoil rope pretty hard till the compression gauge maxed out. Each cylinder took about 4 pulls.

 

[HighTrim]

Re: Lower unit crack

Yes you will get higher readings using an electric starter usually.

 

[reelmess]

Re: Lower unit crack

Just an update on the 9.9, it took some doing to get the lower unit off and cleaned up. The area around the crack seemed almost to have concrete in there. It took many hours of chipping and digging to get it all cleared out. To my surprise its not at all corroded, just cracked. I drilled the ends of the crack, opened up the drain hole a bit and sand blasted the area clean. I then washed the area real good in alcohol, packed in some JB weld into the crack and tapped it closed again. Once I got the crack closed up, I recessed the crack line a bit and JB welded that area and the two holes drilled at the end of the crack. When it dried, I sanded it smooth, self etch primered the thing, went over it with a filler primer and sanded it perfect, sealed it and its ready for new blue paint.

The rest of the motor is ready to go, I've got the new water pump on the bench.

Is there a good close match to Evinrude light metallic blue in automotive paints? I hate to have a quart of expensive paint mixed up just to do one little motor.
Maybe someone knows of a close match off the shelf? (The dealer showed the correct paint as NLA, and aftermarket marine paint was $9 per can. I'm thinking more along the lines of $3.99 Duplicolor for this thing. I figure it'll take two cans of blue and one white.
Was the white on the cover bright white or an off white? Its got a fiberglass cover that's sort of discolored to a cream color but I think that's sun faded?

I'm thinking maybe bright white? (The motor is a 1982 model).

 

[reelfishin]

Re: Lower unit crack

I've had a few motors that were kept in the water, on the boat and used often get packed solid with salt deposits in that cavity, its like digging out dry cement.

I think they were a pretty bright white, I'm not sure if they were 'refrigerator white', but they were close. The last one I repainted got painted Whimbledon white, which is Fords off white used on older cars and trucks, the blue was basically the closest match I found at the autoparts store, the first few I did I think the color was close to a late 70's light met. blue, but lately the best match was from a Dodge.