1976 Johnson 40 HP Outboard Complete Rebuild

[nwcove]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

unless theres a huge price difference......always go with oem parts. jmo

 

[oldman570]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

The OEM switchs will usally be better, but most switches that are waterproof will work fine as long as they are designed to work as a OEM switch dose. JMO
Oldman570

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

Well I am finally assembling the outboard and started out with the lower foot section. Since this OB was totally rusted when I purchased it and it needed so many new parts I also bought all new bearings seals and "O" rings too. And now I have a situation. Can't actually call it a problem because I'm not sure if it is a problem yet. I installed all new "O" rings to include the shift rod "O" ring and I'll admit I had a really hard time getting the shift rod to go through that new "O" ring. But with a little lube and some hard pushing it finally went through. BUT, now I have an extremely hard time making it move up and down. I mean it is so hard to move that I can't see how I'll be able to shift gears once everything is assembled. In fact I had everything assembled in the foot and I couldn’t change gears at all because once I attached the pivot and clutch dog to the shifter rod and closed everything up. I couldn't change the gears from neutral to forward. Has anybody else had this situation and how did you solve it...? I tried to working some more lube into the area and it did ease up just a little but still too hard to shift... :frusty:

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

A little update on this engine rebuild. I attached a few pictures of some of the different subassemblies for this engine rebuild.

Here are a few of them;



Here is the exhaust housing...if looks like something from outer space with all the arms-looking things hanging off it.



And I finished the starter rebuild as well...ready to be installed now...

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

(continued from previous)

Here is the cowling with the finish buffing...



It is coming together pretty good now and hop to finish it this week...okay maybe with this week and next week... I still have other work to do like mow the yard...

Hope to finish this engine and move on to the trailer next...

Have a great day...

 

[nwcove]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

lookin good gm!! you went all out on the restoration, its gunna hurt to get that beauty wet!! lol

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

lookin good gm!! you went all out on the restoration, its gunna hurt to get that beauty wet!! lol

Thanks nwcove. I appreciate that... I actually enjoy doing these projects. I love making old things like this look new and work as well too...
I can finally see this engine coming to gether now. Trailer is next... Watch for more pictures too...

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

Yesterday while getting things reassembled for this boating project and engine reassembly, I again looked at the fuel pump. And I already cleaned it up previously and checked the unit with a vacuum gauge and pressure gauge. And while it seemed to hold a vacuum and pressure, I had that gut feeling that I should take it completely apart and verify everything is work properly because it looks like the original pump on this 1976 engine. And again my gut feeling was correct too. When I finally got everything disassembled the diaphragm was so hard that I was amazed it didn’t have any cracks in it. So while it would indeed hold a vacuum and pressure, it is gone. So I ordered a rebuild kit seeing how the hard parts look perfect. So even a pump that basically checks good, at far as vacuum and pressure, it would not work properly and make you scratch your head why the engine just isn’t running right...

 

[swedish johnson]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

Great job! Im at the stage where i am deciding to go through the same process or not with the same engine. At the moment i have no spark, just put a thread up, and will see about parts availiablity here in Europe before taking the plunge. I recall someone saying about upgrading to CDI ignition, do you have thoughts on that?
Cheers, Ian

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

Great job! Im at the stage where i am deciding to go through the same process or not with the same engine. At the moment i have no spark, just put a thread up, and will see about parts availiablity here in Europe before taking the plunge. I recall someone saying about upgrading to CDI ignition, do you have thoughts on that?
Cheers, Ian

I think I've read your thread this morning about your engine. I too thought about replacing the entire ignition system to a more modern CDI upgrade, but I see and know so many older motors that are running strong with the old points system and I haven't seen any plug and play setups to change to that would give me anything better in performance yet to sway my opinion. So I'm going old school with this rebuilt at this time. Points, condenser and coils are too easy to trouble shoot and repair verses a completely sealed power pack. While I know exactly how those power packs actually work, repairing one is an entirely different issue. Most of the time you are stuck throwing the defective one in the trash and forced to buy new...at a much higher cost then some simple points. I think one of your first issues would be to purchase teh original factory shop manual for your engine. The information in that shop manual is invaluable to say the least. And there are so many assembly and disassembly pictures there to assist you in your efforts...JMHO!

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

Well finally I am rebuilding the carburetor for this engine. I waited until nearly the last thing to tackle because I wanted to do it in the absolute best ability I could. WOW, once I opened up the fuel bowl it was a total mess. There was a tar like substance in the bowl and the cork float was covered in this sticky tar like junk as well. I cleaned it off the float but I really could replace it for a new version. After reading and searching Johnson floats and see how today's fuel will simply eat the varnish coating off any replacement, I was wondering if anybody has tried to recoat the cork with an epoxy (two part) coating to seal them against today's newer fuels? Seems like an epoxy coating would be the best option available since other type coatings could be dissolved with certain fuels and additives. Pictures will follow soon again now that I got my laptop working again…

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

I have this carb disassembled and need to purchase a few parts that didn't come with the carb kit. I had a really hard time removing the lower fuel nozzle (I guess the high speed jet). And after many tries to remove it, I had to drill it out some and use an easy-out to remove the brass fitting. SOooo, I have to buy a replacement now. But not too expensive, only a few dollars. However the cork float is another issue as I have posted about already. I need to either reseal it with some type of impervious to fuel coating or buy a plastic replacement once I locate one... Here is a few pictures of this carb...and how the reassembly is coming together now... :joyous:

View attachment 197841View attachment 197842View attachment 197843View attachment 197844View attachment 197845

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

Well I have some good news to post now. After at least eight tries, I finally have the lower foot sealed and holding pressure. I went through three prop-shaft seals and a tube of a 3M black RTV (room temperature Vulcanizing) gasket sealer/maker before I got it to hold air... Seems I didn’t coat the first seal with any gasket sealer like the shop manual specified and it all went south from there until I stopped and did a thorough cleaning and then a coating of the gasket sealer as I reassembled the foot this last time. I believe I could duplicate that effort the first time if or when I do it again now… Always pays to follow the shop manual when doing things like this… Just for the record, don’t try cleaning the prop-shaft seal holder in lacquer thinner over night. I forgot there was the prop-shaft seal still installed and dropped the sealer hold, which is made out of aluminum, into a container of lacquer thinner to remove all the oils so the RTV sealer would stick… You can probably guess what the prop-seal looked like the next morning… That was the first prop-shaft seal… The second seal I forgot to coat it with the gasket sealer before installing it in the seal holder. And of course it leaked like there was nothing there. So as I removed that seal, I just bought the third one to make sure it was a perfect seal instead of a removed and reinstalled one. So many lessons learned with this effort.

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

I had a bit of a problem removing the high speed jet from the carb fuel bowl being how I believe it has never seen the light of day since it was originally installed in '76. After trying so many screwdrivers without any luck, and using penetrating oils and such, I had to do the unthinkable. Yes I manage to break off any jet material that was there to turn it out with and now all that was left was a flat top brass blank. So I drilled it out so I could use an 1/8" easy-out and remove that totaled jet now... :facepalm: So I ordered a new one. Not really very costly, but I think $8.50 delivered. Sounds cheap until you realize that is nothing more then a 1/4" X 20 TPI brass blank drilled to a .068" inch hole in it... Okay, yes I could make one, but I ordered instead... BUT, once I received the new jet, I decided to make a tool to install it (and remove it if need be down the road) out of an old screw driver that I had laying around. Once I found the proper diameter I started filing and fitting. Took some time but I think it came out nice and will be well worth it if the jet ever needs removed again... I attached a few pictures.



More to follow... :watermelon:

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

After completely cleaning the carb, and that was a serious job too, I started examining every part and wanted to understand exactly how this expensive casting worked. Amazing how expensive these old carbs can be...if you can even find them anymore. So I decided to refinish it so it would not only work properly but also look the part too. I attached some before and after pictures of that job...

View attachment 199876View attachment 199877View attachment 199878View attachment 199879View attachment 199880

more below...

 

[nwcove]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

After completely cleaning the carb, and that was a serious job too, I started examining every part and wanted to understand exactly how this expensive casting worked. Amazing how expensive these old carbs can be...if you can even find them anymore. So I decided to refinish it so it would not only work properly but also look the part too. I attached some before and after pictures of that job...

View attachment 199876View attachment 199877View attachment 199878











View attachment 199879View attachment 199880



more below...

cant get the pics to work gm.

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

Here are a few more shots of the before carb. Look at that crud in the fuel bowl...



Wonder if it would have run... :laugh:

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

Now here are some after shots... I think this will work so much better... :joyous:



Now all I need is to finish the wiring harness and see how this engine rebuild job came out... More pictures later of the total complete rebuilt engine...

 

[nwcove]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

carb looks as good as gold!!!

 

[gm280]

Re: 1976 Johnson 40 HP Outboard Complete Rebuild

carb looks as good as gold!!!

LOL...thanks, I did try to use a few different colors to make it stand out. Everything was also shot with a catalyzed harden clear coats and is now totally impervious to oil, grease, and fuels too. I am nearly finished with everything on this rebuild. All that is left to do is finish up the engine wiring harness and it is ready to start and tune...