Key West - Genset oil change and other stuff

This is about how I felt today

It was supposed to be a simple thing. Just change the oil and filter in the genset. The oil change was fairly straight forward with the vacuum oil pump but then things turned sour. The genset wouldn't draw raw water for cooling. Well, it's true that I hadn't changed the impeller for the last two years but then the genset only had and additional 200 hours on it since the last impeller change.

If you're ever worked on a genset you know that things can be very tight. They tend to pack as much as possible into as small space as they can. This makes for difficult servicing, especially in a cockpit locker. Well, that was my situation with a 6kw Kohler genset. The impeller location was made to challenge the resident mechanic (that's me) into contortions for even getting a good look at the pump. On my Volvo main engine, the impeller pump is located right in front as you raise the stairs, couldn't be easier. Not so for the genset where everything is nice and compact. A lot of stuff had to come off to even start to get at the impeller.

Key and keyway

The fun began when I finally got the impeller free. It had multiple vanes missing. This is not good. Where did the vanes go? The answer, right into the guts of the engine and probably blocking cooling water flow. So everything has to be taken apart. All raw water hoses were removed and the port to the heat exchanger examined. Pieces of the impeller were everywhere. When finding pieces, you then try to match them with missing sections of the impeller vanes and hopefully finding out that you've caught all the pieces. No such luck for me. Further looking found pieces in the intake of the heat exchanger, partially blocking the heat exchanger tubes. After a couple of hours of poking around with various instruments (tweezers, lobster picks, needle nose pliers, screwdrivers,...) I eventually removed the offending remains.

The impeller, obvious keyway now that I look

On installing the new impeller, I noticed that it had a groove on one side which I ignored (it was getting late). Well, that proved fatal. The groove was a keyway and I had not noticed a key fitting it from the previous impeller that had expired although it must have been there in order to operate at all (it ensures the impeller turns with the shaft).

So in starting up the genset, naturally the raw water pump didn't pump - the key was missing! Now I know that key is somewhere in the guts of the genset since it must have fallen out when I removed the old impeller but try as I may, I cannot find the wayward part. After seven hours I called it a day and I'll visit the nearest hardware store to see if I can find a key to fit, hopefully. It would be nice to have a genset on the way home.

We are now looking at leaving Key West on Thursday. It's the last day of relatively calm winds before a week of strong winds out of the east. We hope to make Marathon but we don't look forward to find an anchor spot in the crowded harbor. We would take a mooring but I seriously doubt one is available this time of the year.