Re: [EXTERNAL] [C400] Impeller Change

Frank Falcone

Hi Nick:


…GREAT INFORMATION! Thanks so much.






From: <> On Behalf Of nick walker via
Sent: Monday, June 28, 2021 10:09 AM
Subject: Re: [EXTERNAL] [C400] Impeller Change


Hi all,


A few years ago, I opened the pump and found several blades missing so went looking.  I found them all, plus many more from POs losing blades all lodged in the inlet the oil cooler at the rear of the motor.  That's the first restriction after the pump and is before the cooling water exchanger.  Much easier to check by taking the hose off there rather than the end cap of the main heat exchanger too which is a bonus.



Divided Sky, #232

From: <> on behalf of Frank Falcone <frank.falcone@...>
Sent: Monday, 28 June 2021 9:32 PM
To: <>
Subject: Re: [EXTERNAL] [C400] Impeller Change


C400 Colleagues:

Yes, replacing the impeller on the C400 is a 'task from hell'. Every time I do it, I wonder who and how this 'set up' was designed and approved. Although, the Speedseal Cover makes removing and replacing the cover easier, it does not help in the  removal and replacement of the actual impeller. I use a set of 'hose pullers' to remove the old impeller. This year, I had to find a long stainless steel rod to use, with a hammer and block of wood to install the new impeller. It did not go on easily.  Contortions and 'boat yoga' were on full display. I know of no other way to change the 'set up' to make this routine maintenance procedure easier in the future.

BTW, if a couple of vanes (arms) were missing on your impeller, they're probably logged in the heat exchanger somewhere. ...might become an overheating problem in the future.

...any thoughts from others?

Frank, SILVER EAGLE, #247

-----Original Message-----
From: <> On Behalf Of Andrew Massey via
Sent: Sunday, June 27, 2021 10:38 PM
Subject: [EXTERNAL] [C400] Impeller Change

>> Finally got motivated to change the impeller on my Yanmar which I had been hesitating to do because of the location. All I can say is whomever designed this deserves a special place in hell. Getting the cover off wasn’t too bad but the lack of visibility and leverage that seemed to be mutually exclusive made a 10 minute job on previous boats into a multi hour ordeal with my arms battered looking like I had defensive wounds. The impeller had a couple arms missing and I replaced and used a Speedseal cover kit I had bought previously for the occasion which should make future changes easier (together with a good dousing of grease on the spline). Runs about cooler 5 deg  with the improved flow and a potential problem averted
>> I may well do an access port for easier access as a future mod

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