Have I cooked my outboard??

[Steve_Jones]

Having just moved to a house near the Thames, I was exploring the neighbourhood in our tender (inflatable dinghy) with a 2.4 HP Johnson outboard. After running ok for about an hour at 1/3 throttle the engine suddenly lost revs and died. There was obviously an overheating problem as the engine was making a 'crackling' sound like a car exhaust when it cools. The engine appeared totally seized for a minute or so after which I was able to turn it over using the starter cord. In the meantime I had checked the cooling water inlet on the leg and found it was totally clogged with leaves. Once this was cleared and the engine cooled I started it and ran it in neutral for a while to get some cooling going and to check the flow from the tell tale.

Being a newbie to rivers, is this a common problem and how do I overcome it? Also, what damage might I have done? Is a full strip-down of the engine required? The outboard ran ok for about 30 mins after this (we needed to get home!) and it appeared ok, although it sounded slightly 'rougher' than usual, or did I imagine it?

As always, thanks in advance!!

Cheers,

Steve

 

[lookout]

Yes, you cooked it.

Yep. common where there's lotsa leaves & plastic bags/rubbish - unless you check the inlet regularly.

See above - either avoid the crud, or clear it often from the inlet.

Damage - hmm, well could be lots or very little - dunno without a strip-down. But noo, not required to do this if it runs ok. Unless it's very rough, I'd continue using it and see how it goes. ( you do carry oars too? )

 

[Steve_Jones]

"you do carry oars too?"

Oooh yes! Thanks for the quick reply, I'll keep an eye on the inlet from now on. Has anyone ever designed a mesh cover thingie to cover the inlet to help with this problem? I feel a PBO project coming on!! /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

 

[EdWingfield]

Glance at the outlet every 5 mins - easier

 

[Guest]

Happens often where I am ... river has lilly pads etc. as I exit my canal - they cover the inlet very effectively !!

I have my boat hook ready to hook 'em off ...

As another says - keep an eye on it .. usually if its a 2 stroker ... they seize on getting too hot and once cool - free up and run ok ...

I used to have a Lambretta scooter that regularly seized ... after a year or so of it doing it - had to renew crankcase seals !!

 

[Talbot]

Its very possible that the points and/or plug gap have been altered due to the heat. (especially the points) try to replace these and I suspect it will work fine again.

 

[ParaHandy]

check the water impellor? they go very quickly if run dry.

 

[Billjratt]

Try some chicken wire round the water intake (away from the prop!) as an experiment. It can be bent while you learn the best configuration, then make something more aesthetically pleasing if you can be bothered. If tempted to strip it, get the exhaust manifold off first, then you can look into the side of the piston and see the scores and rings....if it's not that bad, and you can stand the clatter, there is probably a good few seasons left in it before it Has to be done. Give yourself a bit of time to collect the bits cheaply as and when they become available.

 

[VicS]

You have not told us the age of your engine and i have not been able to establish when Johnsons made a 2.4 hp model.

If it is any younger than 1987 then it won't have points, it'll be electronic ignition so the suggestion to check the points won't apply,

Since the water pump was not actually run dry the impeller is not likely to have suffered but unless it has been changed recently then it would still be a good idea to change it.

It is quite possible that the heat has damaged (warped) the cylinder head. That should be considered as a possibility if it does not now run properly.

Since it actually seized damage to the piston. the rings and the cylinder are real possibilities.

Depending on its age it may not be economical to rectify some of these more serious matters.

If it runs OK run it, but if it plays up and is more than just a few years old dump it.

 

[ex-Gladys]

A 2-stroke "seize" as an outboard is not an issue... For us bikers with little hair or grey hair, in the 60's you rode 2-strokes with your fingers on the clutch waiting for it to "nip up". Rapid declutch, coast to roadside, cool and off again...

Personally I wouldn't do ANY major dismantling, and see what happens.

 

[StugeronSteve]

[ QUOTE ]
For us bikers with little hair or grey hair, in the 60's you rode 2-strokes with your fingers on the clutch waiting for it to "nip up". Rapid declutch, coast to roadside, cool and off again...


[/ QUOTE ] Just about to post the same thing, but based on my old karting experiences, although my biggest problem was holing pistons when running lean!. Very unlikely that this will have caused any serious harm to an outboard engine. If it's running ok leave it, if not, whip the head off and check that the rings are free and there is no serious scoring to the bore. Bottom end should be ok, cos it would still have been getting lubricated when it nipped up.

 

[m1taylor]

Absolutely. Don't listen to the prophets of doom. If your engine starts and runs and cools now, don't dismantle it. Run it for a good long while to check that your head gasket has retained its integrity. Yes, the overheat may have caused some wear, but two strokes are very resilient beasts - if it works ok, don't worry!

 

[Guest]

[ QUOTE ]
.... Just about to post the same thing, but based on my old karting experiences, although my biggest problem was holing pistons when running lean!. ......

[/ QUOTE ]

Karting ... best fun I ever had ... Areokart Class 1 ... Villiers 9E3 engine ... fantastic.

Oh - I totally agree with these guys ... if its' running ok ... as a 2 stroker - that's good. Enjoy it.

Let the 4 strokers have the problems ! /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif