On Mon, 16 Jul 2007 07:35:43 -0400, Hanz Schmidt
wrote:

I use 2 microns on my racor(500 series). The engine is a Volvo MD-30.

With a 10 some sludge will get thru..

This topic has been debated endlessly on the Trawler mailing lists
where it was a hot topic for a while. Most engine manufacturers
recommend 10 micron for the primaries, typically Racors, and 2 microns
in the secondary engine mounted filters. Their rationale is that the
10 micron filters capture a lot of the smaller particles also, and
that the secondaries need to be replaced on a regular schedule
regardless.

Sludge is heavy, much larger than 10 microns. If you have sludge
getting through your Racors they are leaking, probably because you are
using FG500s without the necessary spacer. This is a common problem
with the Racor 500s and many people do not know about it. I ended up
replacing my 500s with 900s but that would be overkill for small
sailboat engines.

For more information on the 2 micron vs 10 micron debate look he

http://www.google.com/search?hl=en&q...& btnG=Search

or

http://tinyurl.com/258xnk