Honda 50hp outboard, lying for 3 years

[bikedaft]

Hi,

been given a rib, lying 3 years. Honda 50hp 4 stroke engine, about 10 years old.

took 3 days to get the spark plugs off, they were seized, used plenty penetrating oil, they all came off fine today.

next step is to put warm oil in the cylinders and leave for a couple of days before trying to turn over (by hand). but cylinders are orientated horizontally. i am not used to this! i guess i could rig up a hoist and change the orientation of the 100kg engine, so the the oil will run down through the piston rings. any other suggestions?

TIA

 

[Davy_S]

Possible timing belt?

 

[Boathook]

Water pump. Good chance gearbox bolts will be difficult to remove though.

 

[greeny]

Only 3 years not 30 years. Why should every thing be seized and difficult to get free. Is the engine seized? Didn't see you mention that. Put a spray of oil in the plug holes and turn it over by hand, make sure it's free. Then a service, maybe with timing belt if you want to, and may as well do the water pump as well. Then run it and see what you've got.

 

[Refueler]

Been given !! Wow that's a good present !

Surely its worth passing the engine to service people ... have real peace of mind ? I know it costs - but such an engine is worth it .. you'll also find out if anything is wrong with it.

 

[Boathook]

@bikedaft when it comes to starting it, just turn the engine over for a minute with the kill cord out just to circulate the oil fully round the engine.

 

[Refueler]

@bikedaft when it comes to starting it, just turn the engine over for a minute with the kill cord out just to circulate the oil fully round the engine.

I'm not so sure about turning it over ... OP says plugs were hard to remove ... to me that implies engine has maybe been subjected to water .....

This may have entered the cylinders. Putting in oil is not a solution to 'ease' rings that may have seized ... but a small squirt of diesel fuel may be better ... If the engine cannot be turned relatively easily - I would be reluctant to force it ..

Again I suggest that such as engine is worth good money and certainly handing over to recognised Service Agent to sort it out and give it a complete going over ...

 

[PabloPicasso]

That may well be true, but this forum is about us doing it ourselves.

boats is one of the last preserves of tinkering and fettling. ..

 

[Refueler]

That may well be true, but this forum is about us doing it ourselves.

boats is one of the last preserves of tinkering and fettling. ..

I do not disagree .... but having tried to turn over a generator I had a few years back after it had sat for years unused - the damage that was done basically meant better to buy a replacement genny.

The value of such a 50HP 4str is significant ..... to me that warrants using professional service. Such an engine is not in my mind ... tinkering and fettling !!

 

[greeny]

Really don't know why it should take 3 days to remove plugs after 3 years. Hard to see how they can be that seized unless it's been under water or some other factor we don't know about. Normal hexagon plug spanners can bind in this engine and you need a thin walled socket type to remove plugs more easily. Maybe that's why you had difficulty? Diesel or oil in the plughole and rotate the engine by hand using the flywheel on the top to ensure it's free and push some engine oil round. Once you know its free, then spin it on the starter. Get a bit more lub round. Then change oil and filter and go for a start with fresh plugs or originals if they clean up ok, before spending any more money. If it runs ok, then you can do belt and water pump and change gearbox oil and whatever else you want to do, before putting it in service.

 

[Boathook]

I'm not so sure about turning it over ... OP says plugs were hard to remove ... to me that implies engine has maybe been subjected to water .....

This may have entered the cylinders. Putting in oil is not a solution to 'ease' rings that may have seized ... but a small squirt of diesel fuel may be better ... If the engine cannot be turned relatively easily - I would be reluctant to force it ..

Again I suggest that such as engine is worth good money and certainly handing over to recognised Service Agent to sort it out and give it a complete going over ...

If the engine has been dunked in saltwater I suspect that the electrics have have had it, or at least be very unreliable.