2 Stroke Outboard Servicing

[TmMorris]

And then this is a pretty clear video in an accent that isn't turning every statement into a question and making you wonder if you're supposed to be telling them how to do it :

https://youtu.be/qUzu6ZkeFTw

Get the fuel mix right then get the idle mix on the carb right, check there is a water pee so the engine cooling has some functionality.

It may rev up at that point or it may not, usually when it won't rev up its down to fuel starvation typically from dirt in the carb or line but either way, once it's idling and peeing nicely in a bucket that's the point you need to service.

Only once you've done the basic service will you have a sound foundation from which to troubleshoot or use safely.

This is a good video on your engine: https://youtu.be/5-mg6ZKA_LA

But this multi part series is good for anyone new to outboards and also features a later model Johnson 4.

https://youtu.be/3DrBitg8eME

[A1o]

Originally Posted by Limecc

https://www.screwfix.com/p/no-nonsen...tle-1ltr/46908

Thank you, what I was doing was filling a five litre jerry can and adding 50Ml at a ratio of 100:1 for my Yam 2B... then giving a shake... is it okay to mix like this??

[TmMorris]

Yup. Those bottles above are brilliant for garden tools and small engines as well as being ideal for getting yours up and running properly but your method of 5L from the pump then 50ml of oil (use outboard oil not garden tool oil) or 100mp for this engine is fine. The juggling act comes in when your Jerry can is around 2/3 empty and you top up with 3.64L of fuel and need to add the right oil. . I'm quite dyslexic so tend to come up with the correct answer without thinking but then take 5 minutes of staring like a madman doing the correct double check. I tend to write on my cans not just the ratio but also what that means in ml terms. Ie for 50:1 that 1L requires 20ml oil.

[Jon Tallis]

Originally Posted by Matt

Lovely engine - but that throttle was horrible.

Certainly was. I used to have an Evinrude 2hp (lovingly known as the Moulinex due to its stunning performance [emoji1787]) that ran like a dream but had managed to short it's coil onto the metal throttle lever so it shocked me every time I adjusted the throttle!

[TmMorris]

Using a seahorse on open water was always akin to playing keyboards in a prog rock band while having a seizure.

I remember parting with all my holiday savings aged about 11 to ensure my father would buy the Yamaha instead.

[A1o]

Funny you say that... someone told me last night in conversation always go for Yamaha.

I think your right re the mix as I have two outboards at the moment with one 100:1 the other 50:1 I’d be better of just using the Jerry can for petrol alone then mixing dependent on outboard to save guessing games...

I’m currently using Silverhook 2 Stroke API TC is this okay?

[Fenlander]

So funny. I remember this childhood outboard crossover period well.

Seagull first on the tender which initially hung like a tempting powerful beast on the transom as I was banned from starting it so had to row about harbours. Then I had the idea of rowing right to the opposite side of a harbour hidden from view and starting it unseen. Many attempts with just that pathetic flat phutter noise of a non starting Seagull before if roared into life for a few minutes of glorious engine powered freedom.

Returned oar powered to the main boat to find dad ask did I hear the outboard? Nope I said with all the childhood innocence I could muster. He then stepped down into the dinghy and asked why's the outboard warm then... oops.

A little older with permission to run about under power I had a love-hate relationship with that seagull because it would either start first time... or take about 20 pulls until my arm muscles were burning.

After a few years we "upgraded" to a gleaming white Evinrude as in posts above with that damn mixture control and slide throttle.

Still only about 9yrs old I had a hate-hate relationship with that outboard because I seemed incapable of finding the relationship between throttle/choke/mixture to start and run. Sometimes it wouldn't start at all and it needed the plug out to be dried... other times it would start and die in seconds never to re-start.

Then our boating activities moved onto small sailing craft and bigger stuff with diesel engines that always started and no tender so no outboard.

Rolling on a few years to the 80s I bought my first outboard that was mine... a Mariner 8hp. The most notable thing was it started.... easily.... every time. Then I bought a Mariner 2hp backup motor and it was just as even tempered. I thought back then the reliable usage of these modern motors was life changing.

And so it has been in the decades since of portable Mercury, Mariner, Suzuki, Yamaha, Tohatsus etc... all so easy to use.

[A1o]

I was told not to mess with the that mixture screw as the outboard seemed to run fine when initially tested, is this a possible reason for it misbehaving?

So much great advice on here.. I’m going to open it up when I’ve next got a free day and start to get to know it!!

[TmMorris]

Originally Posted by A1o

Funny you say that... someone told me last night in conversation always go for Yamaha.

I think your right re the mix as I have two outboards at the moment with one 100:1 the other 50:1 I’d be better of just using the Jerry can for petrol alone then mixing dependent on outboard to save guessing games...

I’m currently using Silverhook 2 Stroke API TC is this okay?

Yamaha's of that era are lovely but given that you paid £100? for a barely used Johnson then I think you e got a bargain in the current market.

I'm not that clued up on oils but I thought TC was the rating for bigger, non marine stuff. You certainly want to check that the oil you're using is for marine purposes.

[A1o]

Just a thought E10 fuel how do I know if this is compatible with my outboards...

I think E5 is still available as a premium?

[TmMorris]

Originally Posted by A1o

Just a thought E10 fuel how do I know if this is compatible with my outboards...

I think E5 is still available as a premium?

You don't. It's best to assume with an 80s outboard that any of the plastics carrying or holding fuel may be susceptible to ethanol degradation.

Changing the fuel lines to modern grade plastic is easy. If you have a plastic, internal fuel tank then I'd email Johnson and just ask them.

Ethanol has been being put in fuel all over the globe for decades now. In parts of South America it's there in really high percentages and has been for years so most global outboard manufacturers will have been paying heed to ethanol since the 90s at the latest.

Beyond just the plastic degradation there is the hydroscopic nature to contend with but that aspect is manageable via good practice. Don't leave fuel in the outboard and don't keep fuel in a can for more than a few months and ensure the can is airtight. Most 5L cheapies from petrol stations aren't.

Most premium fuels are remaining E5 which means up to 5% ethanol and often none at all. Esso in the south East still state that their E5 premium fuel contains no ethanol.

Finally, you can buy ethanol free petrol at garden centres. For small outboards that are used irregularly then the simplest solution is to buy 5L of garden centre fuel and have zero worries at all.

For my outboards, both old, I am not troubling myself too much. Once it has become clear they won't be used again this season I'm going to remove the carbs, drain them and the fuel system 100% and spray a bit of carb cleaner in just to wash off any remaining fuel. Then all the fuel for the garden equipment and outboards that is left over will be tipped into the cars and used so that no fuel is kept over wi yet and the new season starts with fresh fuel.

There's really no logic any more to storing fuel over winter. Only downsides.

[Jon Tallis]

All "premium" petrol is remaining E5 for at least 5 years, however not all filling stations will be offering it. Brands vary though - they might call their standard grade "premium" and their premium grade "super" or something. Just look for the E5 logo

[A1o]

Thanks for feedback so far... finally took the cowling off... and nearly had a disaster...

In attempting to take the cowling off I assumed the screw on the top took the top half off... then forgot about it...

I then wanted to see it work with the bottom half off and pulled the starter for it to suddenly loose all tension and not retract... I managed by pure luck to re align the screw and tighten it all back together with the rope retracting!!

Checked the fuel filter a little bit of crud in there... think I will change it regardless given how cheap you can pick them up...

Also had a look at spark plugs apparently running very rich accordingly to friend with some mechanical knowledge...

Glad I took the first step... not as scary as first thought!

[A1o]

[A1o]

So turns out I wasn’t as lucky as I thought... pulled starter rope today and got jammed/lost tension...

I’ve taken top screw out again in the hope I could repair it/realign it, but I can’t and don’t want to risk causing more damage... haven’t got the tools to take the top of cowling off and tbh even if I did I wouldn’t!!

Any idea how much it will cost to fix... I’ve basically undone the recoil starter

[A1o]

Soooo after trying endless amounts of outboard engineers, it became apparent no one wanted to repair the recoil so after a kind engineer (Simon - Engines Dunn - Essex) spent some time on the phone giving some encouraging advice I decided to tackle it head on...

After a number of hours and wearing my hands to the bone I feel I may have successfully recoiled the spring and re assembled the unit, previous attempts saw the spring pop out again after about the 3/4th pull... this time I have numerous pulls without issue appearing smooth..

I’m now noticing the outboard runs hot very quickly... within a few seconds of starting... I’m aware my oil mix is closer to 100:1 when it should be 50:1... because I’m not specifically using oil designed for outboards.. but a general 2 Stoke oil which states its suitable for outboards I’ve been advised to run the outboard at 25:1... as the presumption on the general 2 stroke oil will be aimed at newer outboards.. I’m going to drain the tank and refuel would you go 50:1 or 25:1

In terms of the outboard, I can feel and see a mist exiting the holes on the outboard leg... would a poor oil mix cause the engine to run hot? As in where the fuel tap and sparks are cylinder head are almost immediately to hot to touch..

[Jon Tallis]

Originally Posted by A1o

I’m now noticing the outboard runs hot very quickly... within a few seconds of starting... I’m aware my oil mix is closer to 100:1 when it should be 50:1... because I’m not specifically using oil designed for outboards.. but a general 2 Stoke oil which states its suitable for outboards I’ve been advised to run the outboard at 25:1... as the presumption on the general 2 stroke oil will be aimed at newer outboards.. I’m going to drain the tank and refuel would you go 50:1 or 25:1

In terms of the outboard, I can feel and see a mist exiting the holes on the outboard leg... would a poor oil mix cause the engine to run hot?

YES! Run hot and ruin your engine!
Seems to be something of a reoccurring theme across a number of threads......
If you're running a premix 2-stroke, use a good outboard 2 stroke oil and mix it to the ratio the engine manufacturer specifies - simples
Anyone saying different is talking bollo**s

[TmMorris]

Ok. As with car mechanics, there is no shortage of marine mechanics who are just blokes too ugly to get the big bucks from fraudulent door to door double glazing or tarmac sales. So you have to be careful.

The outboard says 50:1 and marine oil is for marine engines.

You're saying the engine is now running hot and that there is possible steam in the exhaust? If this is the case then you've cooked the engine when running it lean on oil last time out.

The odd thing is that the spark plug very clearly shows its been running with buckets of excess fuel but I seem to recall you mentioning that you were running it with the choke out at one point so that may be why.

Have you serviced the engine yet? Have you had the lower leg off and checked the impeller as well as checking the flow of water through the engine?

[A1o]

Partial service, I’ve cleaned them back up as I’m sure they were new and only blackened following my recent usage, with that said I’ve brought two new ones should it become apparent they are of little value, i changed the fuel filter.. I’ve not had the bottom leg of yet as quite honestly fear I won’t get it back on again in the same order it came off..

In an ideal world I’d be able to change the water pump and propellor alongside gear oil once done would that constitute a service?..

I think the point the person I spoke with was making re the oil I’m using is a generic two stroke which covers outboards/lawnmowers/garden tools etc over one that is specifically for outboards alone..

When you say cooked the engine would that in essence be a write off or recoverable still...

It’s not so much steam from the leg like a fine spray/mist of water

[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.