2 Stroke Outboard Servicing

[A1o]

Originally Posted by TmMorris

The thing is that you ran an engine without enough oil in it and it now appears to be running hot.

By doing the basic service you start from a good base to find the issue but given what has happened you might be better off just doing a compression test on the cylinder so as to rule out having done big damage.

However, you ultimately want to know if the cooling system is working properly so you'll be taking the leg off anyway.

I'd check cylinder compression and if ok and holding then check water flow. After that you probably want to give the carb a clean bit of its overheating rapidly then you want to answer that question first now.

Mate thank you, your detailed responses to a novice are priceless...

Expect further questions in near future haha

[A1an]

Those Seahorses were more hassle than an ex wife imho. Great things to learn on as you are always under the hood.

[A1o]

Cheers Al, I’ve kinda taken that approach now maybe it’s lack of confidence but it’s all new, doing the recoil myself has given me abit of confidence, and just taking the cowling off to get an idea of what’s going on underneath...

I’m looking at it from an angle that it’s not running great atm, so I can’t really make it much worst, and if I do it was an original outlay of £100 which will give me foundation for any future remedial outboard work...

I also have a Yamaha 2B which is naturally slow... but I’ve not once questioned its reliability or felt unsure about it!

[TonyM]

They are Ace, just got one up and runing that had been sat in a garden for 5 years :-)
the "Mist" you refer to coming out the back of the leg is the water tell tale, they don't have a "pee hole" like most other engines.
Get your fuel mix right and run it on the correct fuel mix for a good 15 mins before trying to work out if it running lean or rich.
Unashamed link to my website for a little user guide on how to operate
https://outboard-maintenance.com/how...se-user-guide/
Buy a decent imperial socket set before starting to take her apart......Paint that big screw on top of the cowl bright red so you don't ever take it out again.
Cheers
Tony

[A1o]

Thanks Tony, just seen your post and your link...

If there is water coming from the tell tale is that proof of engine cooling sufficiently?

[TonyM]

Yes it does, the water coming out the holes on the leg is travelling down with the exhaust fumes which means it has made it round the internals of your engine and is now being discharged down the leg where you see the mist.

[Nos4r2]

That Johnson's been sat 25 years without an impeller change. Change it-NOW! If you're only getting a mist, it's not pumping water properly and you'll roast it.

BTW, those Johnsons are known for the coils cracking and stopping to work when warm.

Personally I'd shift it on to someone else.

[TmMorris]

Originally Posted by TonyM

Yes it does, the water coming out the holes on the leg is travelling down with the exhaust fumes which means it has made it round the internals of your engine and is now being discharged down the leg where you see the mist.

I guess it depends on where the telltale is in the line of plumbing. I don't know with this engine but if it pees from a cold start then this means it is before the thermostat so plays zero role in indicating if there is water flow to the head where it is most critical. All it would really tell you is that some water is being driven up by the impeller. As you say, water discharging from the main exit is the key, whether it is enough then becomes the question.

Having now run a 25 year unused engine without doing a basic service the OP is probably at the stage where there's no point in doing anything until a compression test is done to check the head hasn't been cooked?

[TonyM]

Didn’t read that big 😂 at 25 years old it will need a new one ….. No thermostat, if mist or spray of water is coming out the leg, the water has travelled all round the jacket and is cooling the engine

[Nos4r2]

Originally Posted by TonyM

Didn’t read that big �� at 25 years old it will need a new one ….. No thermostat, if mist or spray of water is coming out the leg, the water has travelled all round the jacket and is cooling the engine

Had a few of these motors. There's no telltale on them, just the 6 holes on the back of the leg. There's no thermostat.
If they spit water they're cooling properly. If they're just chucking a mist out it's not enough and you need to investigate.

[A1o]

This is turning into something of a nightmare.. all because I undone that bluddy screw..

Any ideas how to change rope pull on this, all YouTube videos appear to relate to different models..

The rope appears to run between the plates and the end knot would be inside of the casing??

Presumably I have to take the plate apart is there much inside which is going to cause me further pain and heartache [emoji24]

[spartacus]

That pull starter rope needs changed, you can see it's frayed. Quicksilver sell them. There some YouTube videos for rewinding the spring coil by screwing it to a piece of wood, then clamping it before refitting it. If that's a step too far, you can buy a replacement, but it's all cash.

Remember it's just nuts and bolts.

[A1o]

Thanks for response mate, its worst than frayed it’s all but gone.. I need to fully replace it

[A1o]

Starter rope changed, seemed to be easiest part of it all!! Hopefully haven’t spoken to soon!

Now need to find an impeller though all the Johnson 4HP ones I’ve seen after for models after the 78 edition I have..

I just hope this is worth it in end, I’ve learnt a lot so far and gained some diy confidence in process so not a complete waste of time

[TmMorris]

I think that if you've done a starter rope change the other stuff is going to be easy.

Just be gentle with the bolts when you start undoing them to get to the impeller. There's a good chance that they might be stiff and you want to YouTube a few videos on how to release old bolts so as to minimise the risk of shearing one.

[TonyM]

Easy enough to find an impeller on eBay for the Evinrude 4hp if you are stuck ring wills mating in Kingsbridge they are evinrude dealers. Very helpful and will post spares.