1973 Johnson 65 hp Powerhead rebuild

[VoodooCapn]

I broke the rules and now I will pay for it. I am a greenhorn, rookie, novice, idiot. LOL! I just bought an old tri hull with a 65 hp johnson. Motor was MILDLY sluggish but overall ran pretty good. I took it out a couple times and other than choking a bit when cold, it ran like a champ. Last weekend we put in and as it turns out the water was juuuuuuust a bit too shallow. I didnt catch it till it was too late. Saw a white puff out the back and now my compression is 90 on the top and 130 middle and bottom. I have done enough research to know that this means im going to have to tear into it. I am not intimidated by the project and am kinda looking forward to tinkering. Obviously Id rather be on the water rather than in the shop tearing stuff apart and spending a fortune on the Cuss Jar, but thats not the world i live in at the moment. Is there a chance that I wont have to rebuild the entire motor? I read that it may be a stuck ring or as simple as a gasket. If i have to machine the applicable parts i can, but would rather not. Im ordering a sealoc manual to assist, is there a better one? Upgrading to a newly rebuilt powerhead isnt an option anymore that upgrading the boat. LOL! A new powerhead will cost more than I have in the boat. So my theory is that if I do the work that i can still come out ahead of the expense curve. Im a generally technical person (plumber by trade...not mechanic,) and i figure half the battle is being willing to take it apart and label every nut and washer. Any advise (that is constructive) is welcome....esp super secret ninja secrets to help prevent replacing 20 ratchets that force me to chuck them into the woods.

Thanks in advance,

Dave

 

[flyingscott]

I doubt you have a stuck ring. Sounds like your water pump went out or the water inlet was pluggedespecially with the dreaded white puff. First thing to do is look the boat over and make sure it's not waterlogged or any major damage before you fix the motor. If you are lucky you warped the head first thing is take that off and inspect the bores and head gasket for damage. If those do check good you are on the road to a teardown. The factory manual is the best. One trick go to the dollar store get cheap ziploc bags and put all the bolts from each assembly in one and label them that way

 

[VoodooCapn]

My wife has a PhD in keeping the disordered state of my life out of chaos. I will enlist her services LOL! Thank you for the assistance. I have crawled under the boat and there doesnt seem to be any damage. I made it about 30' from the launch and then..."Son of a BEACH." I am figuring that a tear down is eminent. Im hoping for a head gasket fail, but that seems unlikely. To further fill my Curse Jar, the first bolt i when to take out is stripped and rounded. I bathed the entire motor and myself with WD-40. I have a scope i could use to look at the cylinder walls, but i believe that with the loss of 1/3 of the power that i had before that its kinda a lost cause. Is there a good place to order parts from? I am currently negotiating with Napa.

 

[Faztbullet]

If you rebuild it discard the small Ibeam rod and replace em with the A frame style

 

[VoodooCapn]

I think you are speaking some form of english.....(i born stupid and got taller.) Please elabortate

 

[flyingscott]

He is talking about the connecting rods your motor has the light version that are more prone to breakage. The later motors had a beefier connecting rod that are much more durable. The good news is you should be able to sell your connecting rods for about the same as the other ones will cost. There are some guys out there still racing those motors and will buy them as the rods are NLA. The boat damage I am talking about is make sure it is not waterlogged and the transom is not rotted. My opinion would be try to find a 1978 or later 70 hp motor they show up reasonably priced. I bet the money laid out would be similar.

 

[emdsapmgr]

If you are going to do the work yourself, you need to ditch the Sealoc service manual. It's junk. Get an original year factory manual from the original publisher: outboardbooks.com. Sometimes you can get a used original from ebay. It is permissible to install just one new piston-but you need to replace all 3 ringsets-assuming the block walls are not too oval-compare with the factory specs for rebuild tolerances.

 

[VoodooCapn]

As I see it, and please correct me if I am wrong, if one is going to tear it apart, wouldn't it be better to replace all the Pistons and applicable parts? Bolts, covers, and misc parts will most likely be re-usable tho... As for the money laid out to rebuild vs replace, that's not really applicable to me. I could buy a new motor tomorrow. What I am mainly after is the education. I never want to be in this situation again. The "not knowing" is worse than the rebuild for me.

 

[racerone]

Start with removal of the cylinder head.----Inspect and go from there.----If you are doing this kind of work for the first time then relax and do things one step at a time.

 

[VoodooCapn]

Do i need to remove the lower end before i start removing anything else?

 

[racerone]

The best place to start is with the cylinder head.--No need to remove the lower unit to do that.---Once you inspect the head gasket and cylinders you can move forward.-----The lower unit will need to be removed later for a new impeller and other simple inspection.

 

[emdsapmgr]

If the cyl walls have minimal taper and are not too out-of-round, you can reuse two of the pistons. It's not a problem if you decide to replace all 3. A single replacement factory piston will weigh exactly what the other two weight. The only requirement is that all 3 pistons be from the same manufacturer, so they all expand at the same rate.

 

[Faztbullet]

Here ya go....

http://nashville.craigslist.org/boa/5383731714.html

 

[VoodooCapn]

I'm so on that! Thanks a million!!

 

[Faztbullet]

Good talking to ya...let the forum know what ya find when you pull head.

 

[VoodooCapn]

Yes sir. It was good to speak with you as well. I got the thermostat cover off and found that I don't have a thermostat...what the heck???

 

[VoodooCapn]

In this specific case I think that that has worked to my advantage. But shouldn't it have one?