Originally Posted by sigmasailor
Not yet; keep it like that and replace it before parts go missing and end up in hard (or not) to reach places.
Sigh... you better read it then instead of pushing irrelevant info. I do not get impeller debris in odd places even if I blow dozens of impellers... because I modified the raw water
circuit to prevent this.
That impellers, many old ones and some new ones, fail is a fact. Replacing impellers frequently will not prevent this completely. At some point one has to make decisions between safety
, amount of maintenance
and ease of maintenance
. Also, experience will steer you towards better systems and better maintenance schedules.
Another tip: route
the raw water
hose from inlet strainer to pump so that it approaches the pump from above, even if it connects to the bottom side of the pump. This simple thing puts the pump in a low point in the circuit so that it won't have dry starts. This prevents 90% of impeller problems too without the possibility of installing a new but flawed part. Buying
first grade impellers instead of the cheapest also helps.
To make sense from these wildly varying pieces of advice: if you hardly ever run the engine, you probably need to replace the impeller yearly (or remove it for the months that the boat isn't used!). If you lack the knowledge or will to inspect the impeller properly, you better replace it yearly. When you run the engine regularly and inspect the impeller regularly, there is no reason why an impeller wouldn't last two or even three years. Also, if there is partial failure after a passed inspection
, you will still have sufficient cooling
to pass the reefs
. A quick pointing to the injection elbow
with the IR thermometer (5 second job) will show you exactly what the condition of the impeller is. With some experience, you can even tell how many blades are missing from that temperature reading.
In the end, what matters is how often you experience mpeller failure. When another approach of this problem results in less failures, ignoring that alternative approach equals to SM
For some, who hate taking heat exchangers apart, a strainer that catches any impeller parts makes sense. Mine catches way more than that, like crabs, fishing
line and hooks that I used to find in the heat exchanger
before I added this extra strainer.