I agree with jm_wilhelm -- having realized we ran for 7 years on a single
impeller, and noticing the engine temperature rising on our winter haul-out
transit, we discovered half the impeller blades had broken off. Lucky for
us, we were able to account for each blade upon replacement. It is generally
recommended to replace the impeller annually given how cheap and easy it is,
though I personally believe every 2 years or 50 hours of engine runtime is
probably sufficient. Woe be you if the broken impeller blades get sucked
into the heat exchanger, or worse, a manifold inside the engine. I'll note
that engine temp rose by only around 20 degrees owing to half the impeller
blades still being intact at replacement.
On a related note, is there a zinc on the heat exchanger? How can I find it?
Persephone ('88 hull 6480) has always run in freshwater, is it true that
zincs tend to degrade slower than in saltwater?
David
On Thu, Jul 30, 2009 at 8:20 AM, <[email protected]> wrote:
>
>
> If your having slight overheating issues check your impeller since it might
> need replacing...or check to see if you raw water intake isn't gunked up.
> Those would be more likely causes
>
> -----Original Message-----
> From: "Jeffery Sheler" <[email protected] <jsheler%40cox.net>>
>
> Date: Thu, 30 Jul 2009 13:08:58
> To: <[email protected] <IC27A%40yahoogroups.com>>
> Subject: [IC27A] Universal M-18 heat exchanger
>
> How often should one clean out the heat exchanger on the M-18, and what is
> the correct procedure for doing so? I've noticed that the engine is running
> a little hotter than normal lately and I'm thinking it may be time. Thanks
> in advance for your advice.
>
> Jeff Sheler
> s/v Windsome
> Portsmouth VA
>
> [Non-text portions of this message have been removed]
>
>
>
[Non-text portions of this message have been removed]
