Merc 4hp cooling

[aitchw]

I have just returned from this year's trip to Torridon during which my Merc 2hp 2stroke did sterling service yet again. I did notice however that on start up from cold I would get a lot of water through the telltale which would steadily diminish to a trickle/drops after a warming up. The motor ran happily for an hour or two continuously at moderate revs. without missing a beat on a couple of occasions so I can't think that she was overheating. Anyone any comments on this as to whether it should concern me?

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[Talbot]

would certainly recommend a de-crystalization this winter, (i.e. cylinder head and bottom removed from the block and scrape out the water passages) sounds like you have a salt water crystal shifting around and then blocking (probably the tell tale only)

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[willothewisp]

Probably salt crystals. Make sure you have a length of wire on board, with which to poke through the outlet. You'll see water coming out in jets again instead of a dribble. Had this on good authority from a mechanic, and don't go anywhere without a piece of wire myself.

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[maxi]

You may well find that the spigot on which the tell-tale hose fits, is mild steel pressed into the aluminium head (it was on my Mercury 4), and this surprisingly rusts and closes itself up. I had to drill it out and araldite a stainless tube in it's place.

Comments re salt crystalisation are also wholly valid, I had long and robust correspondence with Southwester (UK agents at the time) who stated that the Mercury should never be run for short periods such as from jetty to yacht, but should be allowed to run for long periods at full temperature every time, and should also be thoroughly flushed through with fresh water after EVERY usage. Upon referring to the fact that this engine was advertised as the ideal yacht-tender engine and that there was clearly breach of Advertising Standards - I was strangely offered free lifetime annual servicing.

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[aitchw]

Thanks for the comments all of you. Will get to clean and flush out over the next couple of weeks and will apply the suggestions.

Chers.

Howard

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