Yamaha 2 hp 2stroke not cooling?

Niander

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I used this on the tender yesterday but
noticed no water from the 6 holes half way up the leg
should there be water from these?
it didn't seem to overheat but i was just pottering anyway
 
I am sure VicS will be along and give you a definitive answer, but on my Yamaha 2 the tell-tale water came out at the top of the leg behind a rectangular plastic deflector. Excess water plus exhaust came out of the holes you mention.

(replacing the impeller on that engine can be a bit of a pain :( )
 
The leg should, I am told be only hand hot after 10 minutes running. Any hotter its not circulating properly. Maybe the impellor, but also I have had one where the cooling channel inlet to the head had blocked. A simple job to whip the head off, clean it out and new gasket.

Unless a head bolt shears! Dont ask me how I know.....
 
Excess water plus exhaust came out of the holes you mention.

(replacing the impeller on that engine can be a bit of a pain :( )
There's an overhaul kit for the impeller which includes the pump chamber I think. It's difficult but so long as you don't force it, it all comes apart - mine was only 8 years old at the time and much mistreated ...
 
Salt buildup

I have one of these engines for the tender; it has been submerged 3 times over the years due to my stupidity but still behaves like magic !

I've found recently that the cooling waterways clog up with salt - despite rinsing the engine in fresh water at beginning and end of season...

The waterways were also eroded, my rather ace engineer Father built them up again with 'chemical metal'.

I always put my hand under the outlet to test the temperature, if it got more than slightly luke-warm I'd think there was a problem.

Ron Hale in Portsmouth seems to still have gaskets & spares.

Top Tip ;our sailing club keeps a deep sink full of fresh water with a hose at the top of the slipway so that one may flush engines through.

An alternative a mechanic chum uses is a wheely bin full of fresh water, it might cause a councillor to faint on the spot but it works very well !
 
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I found that there were snags with using a wheelie bin.

an old water tank has proved to be more satisfactory



DSCF0419.jpg


DSCF0417.jpg


DSCF0414.jpg
 
I like that tank ...and of course the seagulls
anyway big success!
had a look today first the impeller?
spot on nothing wrong with that
then i tried blowing up the cooling water pipe using a tube
i could hardly get anything through
so off with the head
and total blockage! salt!
cleaned it all out
and all faces clean
back together..bit o red hermetite
and jobs a good one...loads of cooling water now...:)
i will be running in fresh water after the sea!
 
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