Out board engine 2.5hp - HOW hot is TOO HOT?

[tim_ber]

2 stroke

Water tell-tale spurts fine.

But it is always cold, never warm. Yet when I touch the underside of the cylinder head it is too hot to touch, so shouldn't the water in the tell-tale be warmer? (if it was doing its job).

Top of cylinder head is fine to touch.

So, am I worrying needlessly (just fitted a new impeller - no difference and old one was not too bad) or is the cooling water not getting to all the parts it should? - sounds like an advert for Heineken.

 

[No Regrets]

Sounds fine.

 

[catalac08]

Many outboards thermostats are set to start to open around 60 degrees c and be fully open by 70 degrees c. Overheat starts when the head reaches around 90 degrees c. Obviously varies from make to make but the head will normally be too hot to touch. Outboards I have had have tell tales spurting water that feels cold to the touch but presumably hotter than the intake temperature. A cheap temperature indicator is a fridge/freezer digital gauge (normally read hot temps as well as around zero) cost about £7 and this will give you an indication of the head temperature which may reassure you.

 

[VicMallows]

Many outboards thermostats are set to start to open around 60 degrees c and be fully open by 70 degrees c.

This is a 2-stroke 2.5HP. I have never come across one with a thermostat

Vic

 

[pampas]

most small outboards I have worked on, the water comes up the leg,entering at the bottom of the liner/bore casting through the head down the other side of the liner and out to exhaust. The tell tale normally is taken off opposite the entry side hence it should be relatively cool.

 

[monkfish24]

That hot part is the exhaust!

 

[tim_ber]

Doh !!!!!


What a laugh that gave me. I feel such a plonker !

But relieved too.

Thank you. Just got to make up some shear pins and I'm away again.