Evinrude 3hp 1966 rebuild

Hello everyone, this is my very first message to the forum.
I got Evinrude 3hp, 1966, for free and now i am planing to do complete rebuild for the engine. I have already done one rebuild for one Mercury engine, so the work itself is not new to me. Also this Evinrude, seems very simple engine. Also i am going to paint the whole engine again during the work.
Anyway right now the situation is: before my ownership the engine was overheated and seized. I got the pistons moving by putting lot of oil to the cylinders and let it be overnight. After that i started the engine. It runs very smooth, and really feels okay without too much smoke. My test drive took about 1 hour, then i put engine to the boat and begin my short trip. Everything was fine until i give it little bit more gas. Nothing was happen, engine only runs about half speed, even throttle was about 70% setting. Engine only run half and under, speeds. It does not take more revs. But there is no any unusual sounds, only smooth engine sound. So, today i took of exhaust-plate cover and looked about piston rings, upper cylinder one ring is not good, all others rings are good. One piston have scored marks on side. After took of cylinder head, i saw very shiny cylinders without scoring, but cylinders really need to be hone. Anyway, there are no anymore new pistons to available to this engine. My question is: If i buy new pistons,connecting rods,pins that are for 1982 4.5HP engine, do you think it will work? I know there is different bearings in the rods, but bore/stroke is same in that 1982 4.5HP engine. It would be nice to hear what others think about my idea?
Of course my rebuild will include: Hone, complete cleaning, new washers,new impeller,new reeds,rings, carburettor cleaning. I just really want to save this nice engine. Thank you

Go to the Antique Outboard Motor Club's website, www.aomci.org and post a wanted ad on their classified ads page. There's gotta be a lot of the correct pistons out there. Heck I might even have a couple of used ones myself, but haven't looked. The ad is free, so nothing to lose by trying.

Agreed ------You can find a lot of correct used parts for those motors.----------Much easier than for some newer motors.

You shouldn't need reeds, clean used pistons are available, got some around here in my shop. Gaskets and rings for sure are available. My first overhaul was a 2 1/2 hp Johnson, even got new decals. Did that back in 1966. The piston scoring may be tolerable, got any pictures? All pistons will score to a certain extent. They can likely be cleaned up and very lightly hone the cylinders with about a 30 degree crosshatch, then new rings. Would be nice to get an accurate compression test before you tear down. Be careful with head bolts, don't break them off, might use a little butane torch or Mapp gas heat if they are stuck. My guess is that it doesn't power up well if it has low compression. Probably 45 psi.

Thanks for help ! I become also to think, that maybe i can try to clean my pistons, but i am not quite sure how should i do that? with very fine sandpaper, moving it horizontal way? I have not yet started my project, just planing it right now and also i need buy some tools, example i need to buy 2 different torque wrench, which are quite expensive. Do you think i really need tool for ring change, or can i just do that with my fingers? Is traditional motor oil good to use with hone? i have thinking to use medium stone with hone.

Got a Harbor Freight around, stuff there is cheap, also check on line, even ebay find used stuff. Handle rings by hand and clean up piston with light wet or dry paper, maybe 280 to 320 grit and use water. For honing you can use the same stuff, wrap it on an object that fits inside the cylinder nicely and connect it to your variable speed drill. No need to buy a hone if you don't want too. Use water with a little dish soap for honing. When doing automotive engines I use medium grit stones with mixed gas and fuel oil as a lube, flushing agent. Can you take a picture of the pistons through the exhaust port? Can you get a compression tester? It will be so helpful with all your future work. I still have my very first one that I bought back in 1972.

Your lack of power may have been a result of running on one cylinder. And that might have been terminal engine damage as you are suspecting, OR it may simply be an ignition problem.

Note: These are extremely hard starting on just one cylinder, but agreed, arcing from coils, whether external or internal can provide enough spark for what you need to start the motor, then falter when speeds are increased. Remember, Mr. Evinrude thought the motor was damaged and seized from overheating I would suspect more a dry seize, so probably low compression, but enough compression to get it started. Is the paint about the head discolored? Red flag then.

I hope you get your old Evinrude running. I think the 1966 Evinrude and Johnson 3 hp motors are among the best little outboards ever made.

I refreshed my old 1966 3hp Johnson Seahorse last February and March that I inherited from an uncle and got her running like new again. Great little motor.

I grew up at my grandpa's Three Rivers Boat Dock & Restaurant in Knoxville, TN back in the 50s and 60s and he rented out these little motors along with 5 and 10 hp Johnson and Evinrude's. Very reliable motors that would take a beating.





The carburetor looked clean inside when I took it apart but there were some passageways that were clogged up that kept it from running.






I replaced the impeller.





The old coils looked good but one of them was dead so I just replaced everything including points, condensers, plug wires and plugs.




Running like a Champ!

Nice little white ball Rook66!... looks like if you trimmed the protruding metal at the right and left rear end and took the tiller/front handle off, you could also play soccer with it.
Seriously, nice lil' time capsule tho. Looks like original paint too? Amazing condition. Only possible with a fresh water used motor... damn salt! lol

Hello everyone ! Now i can tell you some updates, about my project with Evinrude Lightwin. Well now i have my powerhead taken off from lower unit. Also i have taken off fuel tank, ignition system..
My ignition system looked clean like new. All points, coils etc, are clean like new. Someone have surely done ignition project before me. But i need to buy one new coil, since one wire is almost broken in one coil. Reeds looked like new. I have buy new gasket set+new needle and float to carburettor. Also carburettor needs cleaning work for sure, even it seems to be ok inside. For starter, i am going to replace rope. My plan is, to clean everything as good as i can, put all new seals, and in the end, i will paint my motor. Tomorrow i will know, what is the situation with the piston rings. Of course new impeller is also coming to water pump. I am sorry that i have no photos to show you now, but i will show you some photos after my whole project is ready. How relaxing i feel, when i can sit beside old motor, and clean parts

Evinrudemen said:

But i need to buy one new coil, since one wire is almost broken in one coil.

Click to expand...

You want to make sure you tuck the coil wires back away from the shaft so they don't rub. Especially the lower one that goes to the points.

That is probably the reason one of your wires is broken or frayed now because someone in the past didn't make sure the wires were tucked back away.

I think so too about coil wires. Today was good day with the motor, my all piston rings are good enough to put back to use. One ring was partly stuck, but i got it working with oil and time. Well of course rings are not good as new-ones would, but anyway they seems to move and snap back after pushing, without problems. So next step, i need clean power-head, hone cylinders and i need to put new O ring to my crankshaft. Brass- bearings seems to be good condition too. One thing i have really learned with this project, it is super super hard to get off old gaskets. Step by step, Lightwin is coming back to life

Glad to see you're making progress with your motor. I look forward to seeing pictures of it out on the water or in a barrel running like she was in 1966.

Today i have spent time with cleaning my powerhead. Also i spent lot of time trying to get off old gaskets, well gasket-work is nothing but ready, anyway i think i can show you some photos related my gasket-work, today

All the old sealer in picture 3 must be cleaned off.---All of it.-----Use ---Loctite 518 or Evinrude " gel seal " when assembling.

Yep that´s for sure, and it really takes time. I have already Permatex Anaerobic gasket maker, for this job.

The correct sealer must be used.------Most all of it should squeeze out for a METAL TO METAL fit.----No fillers in the sealer.-----Use LOCTITE 518 ---or factory" gel seal " for this job.

Okay thanks, i will write down Loctite 518 to my shopping list

Okay after nice day with the motor i can write some updates. Yesterday i cleaned off all the gasket surfaces. Also i checked and cleaned the reeds, which seems to be super good condition. Today i have cleaned carburettor, it was nice to notice that my cleaner made good job with little effort and now my carburettor is very clean outside and inside. Tomorrow i am going to put new float-valve assembly, new float, and new gaskets, then carburettor is ready. On Monday, i am going to visit one rubber-shop, they will make me some new gaskets for reeds-valve, gaskets for gas-cap, and upper O ring to the crankshaft.

Huh? New rings are 20 bucks, you can't get them? Where are you located, Evin? Overheating will remove properties in your piston rings that will compromise compression, and as a result fubar the expected results of all your work here. You DID say that the motor was overheated.

It was not so easy to get them, here in Finland. My old rings are good enough to use again. I made it clear to myself that if i later find that rings not work, i will buy similar Evinrude or Johnson outboard for parts. Here in Finland, they sell those engines sometimes on internet. Anyway, lets hope for best.
My last post i forget to tell, that yesterday i also made light honing to cylinders.

Hopefully you won't have the same problem I did on my '66 Johnson 3 hp carburetor. I cleaned the carburetor and everything look good and when I reassembled everything the motor would still not run. I took the carburetor back apart and this time I removed the expansion plug which I didn't remove the first time and cleaned it again and blew out all of the orifices with compressed air. The first time I didn't remove the expansion plug and there was some debris left in there that didn't get cleaned the first time.

The carburetor repair kits come with a new expansion plug.

I have faith in your judgement, hope the rings still have maintained their integrity. In USA, we have piston ring shops, like Hastings, that can make whatever ring you need. I have used them for applications like air compressors over the years. The cost is very reasonable. eBay can ship you original OMC rings too. I have sold things on eBay to several customers in Europe and Iceland.

Note to Rook. Air will blow through and become clear, but later on debris present and trapped in the chamber, under the plug, will reposition and stop things up again.

You can buy new rings on this site. Go to the top of the page and click on the MarineEngine.com and then click on Evinrude Outboard and then type in your model number. Then the parts diagram will appear where you can find the rings.

Or you can type in Evinrude 3 hp rings on e-bay and find there are a lot of new rings for your motor for sale there also.

This is just my opinion so take it for what it's worth, if I were going to tear a motor all the way down like you have I would put new rings in it just so there wouldn't be a chance of having to tear it all down again because the old rings failed. They're just to cheap to not replace. As I said just my opinion.

Good luck.

????-----I would say that $75 / cylinder is NOT CHEAP !!!!!--------For that kind of coins ( $150 ) I would pick up 3 parts motors or more.-----One of them would have like new rings in it !

You can get new rings for $13.95 on e-bay with free shipping. Well actually you can get them for $12.15.
https://www.ebay.com/itm/PISTON-RIN...277669?hash=item3ad53759e5:g:pO0AAOSwUEVYEGVB

Well time for some updates. Okay, i have made my decision and i am going to buy another 3hp lightwin, for parts. I find that one is for sale near my town and i asked about owner what is the condition, and engine is normal working condition, never seized. After one night without sleeping, i made decision to buy that engine for parts. price was also nice. I am going to get the engine to my home before or after coming weekend. Then i am going to tear it down too, and take the better pistons (and rings) to my project Evinrude. Pistons are all i really need need since everything others are good in my project engine. Well, then i have nice spare parts for coming years About my project, tomorrow i am going to replace the rope for starter. Starter is already cleaned as good as possible.

So some updates related my project. Well now i have 2 nice, used, but better than old-ones pistons with rings, assembled to my block. These "new" pistons seems to be much better condition than my old ones was, and rings are also better condition. Today i cleaned the pistons, and assembled them to my honed block. It is nice to feel, how much cylinders feel better and tight after hone process, and also there is now some resistance when i try to push or pull the pistons. So right now everything looks nice. Also now i have some good spare parts for coming years. The engine that saved my day was Johnson 3hp, 1963. Here i have photo of that Johnson, and also my block with pistons assembled.


Thank you Johnson 3hp for your help


And yes, pistons are in place with new lock-rings