1987 Mercruiser 165 HP Impeller

[Jimshoe]

This is a simple one I just don't know. How often should the impeller be replaced?

 

[ziggy]

Re: 1987 Mercruiser 165 HP Impeller

per s/m #6...

"task- seawater pickup pump- disassemble and inspect...
interval- whenever insufficient seawater flow is suspected. (if operating temperature exceeds normal range)"

that said. in s/m #2, for my rig in my sig. it states to go look at it yearly or every 100 hrs. imho, this is more proper for an alpha1 type impeller. imho, they are fragile. i go look at mine yearly, i always find some permanent curling to the impeller. this is the start of a failing impeller.

also, for any overheat condition, the impeller is usually the first place to look.

 

[Don S]

Re: 1987 Mercruiser 165 HP Impeller

Every other year is a good rule of thumb, if you intend to run your boat during the summer instead of work on it, and have problems on those hot 3 day weekends.
Changing it during winterizations the best time. The drive is off for other maintenance (or it should be) and the gear lube is drained for changing. Perfect time to put in a new impeller and a couple of gaskets, put it back together, pressure test the drive. Refill with gear lube and it's ready for summer.