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Bombay Explorer 44
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Discussion Starter #1
Well I was zipping across Falmouth harbor in Antigua when my two year old Tohatsu 18hp 2 stroke started sounding very unhappy and slowed down.

I throttled back and it clonked on for a moment or two before stopping. It restarted briefly but now does not turn at all. Some kind of catastrophic failure. :mad:

My situation is complicated of course by the fact that I bought the OB in St Maarten and am now in Antigua with no intention of going to St Maarten this year.

Now Tohatsu offer a five year warranty. Has anybody had any success claiming on this.

Or should I just buy a Yamaha?
 

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Corsair 24
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well what happened have you take it apart?

sounds like it soft seized...since it restarted

so it can be as simple as rings and a hone job...sounds like a lubrication issue
 

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If it stills turns over but won't fire it is probably because of a fouled plug from too much oil mixed in the gas.
Pull the plug, clean it up and remix some gas with the proper ratio of gas and oil.
If it is seized and will not turn over by pull starting it, then it is more than likely it did not have enough oil in the gas.
If it was starved of oil it will be obvious when it is dismantled and you will have voided the warranty by using an improper mixture of gas and oil.
 

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well what happened have you take it apart?

sounds like it soft seized...since it restarted

so it can be as simple as rings and a hone job...sounds like a lubrication issue
.... or fuel pump diaphragm or electrical/coil failure.


Have spark? if not evaluate why not.
Getting fuel? if not evaluate in a logical sequence of why not.

If unsure get a copy of the Maintenance Shop Manual for this engine and follow the logical progressions to evaluate: Defender.com Search Results: tohatsu service manual
 

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Did you pull the plugs to see what they look like? White dust, burned or black and sludgy?

Air, fuel, combustion. Check them in that order.
 
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Corsair 24
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it can be many things...fuel air and spark...go from simple to technical

since you say it sounded bad...

may I ask was it KNOCKING, RATTLING or did it sound like it was missing?

honestly it can be a very simple solution

check plugs first

I mean it could be as simple as a fouled plug and pistion tops causing detonation and making that ugly sound..

it wont restart cause the plugs are too fouled

or it can be catastrophig to a point were your mix was to lean causing a soft seize and rings to melt and tear up the cylinder walls

check the simplestuff first and report back

hope we can help
 

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Corsair 24
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the neat things about 2 strokes are they are simple if its beyond your mechanical skills you can put in your shoulder and take it to a shop and get it at least diagnosed

if you need parts and labor is expensive a lot of the work can be done on your bench on the boat
 

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Bombay Explorer 44
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Discussion Starter #8
Thanks for all the advice. I have pulled the plugs which are normal. I used to race 2 strokes and know the symptoms of a piston seizure. This is not the case here. It MIGHT be a bearing cage break up. The engine is now locked and will not turn at all in either direction. This was after a few pulls on the starter where it would turn. I suppose it could be a broken ring jamming in a port but you usually get a little movement then. It is not a lower unit seizure either. It behaves the same in gear or out and the prop turns freely in neutral.

The engine has always been run with the correct fuel oil mix. Initially 50 to 1 then 100 to 1.

I am not too hopeful about the seller in St Maarten coming through with a repair under warranty so was wondering about contacting Tohatsu directly.
 

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Let us know what happens.

My old boat had one of the last small Johnson 2-strokes made. It was running great at 7 years old. My new one had a Mercury 2-stroke that was running great at 37 years old.

Dangit Canada would be nowhere if it wasn't for Johnson 6hp 2-bangers.

If Tohatsu doesn't own up to their product, we can all send them an email saying we'll be voting elsewhere with our wallets, and mention that we know you :)
 

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Does Tohatsu specify 100:1? All of the two strokes, both large & small, I had specified 50:1. Except for a 1947 Johnson 5HP, which was 20:1, IIRC.

When I switched to synthetic oil, IIRC the directions said "Mix to the Manufacturers specifications", or words to that effect. As mentioned, possible cooling related problem causing seizure? Perhaps fixed high speed jet partially plugged, causing overly lean mixture, or partially plugged filter? Let us know what you find, interesting case.

Paul T
 

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well sounds like you know what to expect...tear it down and find out!

good luck
 

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If you bought it through Budget Marine, any one of their stores will help you out with the warranty. I'm not so sure about Island Marine, but you could ask.
Budget has been terrific with the windlass we bought in St. Martin, but didn't find out it didn't work until we installed it in Grenada, 4 months later.
Been wondering about the Tohatsus, so please keep me informed (by PM if need be) of your progress and what happens w/ the warranty. Thanks. We're in Jolly if we can help?
 

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Bombay Explorer 44
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Discussion Starter #15
I like having a fast dinghy hence the 18hp. It allows me to anchor well out but still get in and out in a reasonable time. My AB rib has big tubes which help to keep you dry but they really suck under oars. Really Really suck.
 

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A 100:1 is a pretty lean mix, is that what is recommended by the manufacturer?
All of our two strokes at work run on 40:1 or richer. Yes they smoke but they keep running.
Personally, I would rather have to clean the plug periodically than rebuild the motor.
 

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Sounds like bottom end.

Or the fuel oil mix. My Tohatsu Everrun 18hp is 25:1 running in for 10 hours and the 50:1

As others have said, where did u buy it from? Budget Marine is the agent in SXM so why not try the new Budget Marine in Jolly Harbour?

Good luck!

Mark
 

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Bombay Explorer 44
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Discussion Starter #19
Well it is a failed bottom crankshaft seal that allowed water into the lower crankshaft bearing which then failed.


The bearing cage broke up.


Collateral damage to the piston.


I am now in contact with both the local branch on Budget Marine and the main office in St Maarten. This was where I bought the engine in March 2012.

I will pass on developments as they occur.
 

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Yikes. Hope you sort it out quickly.
 
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