Hello all, I have a C34 Mark 1.5 (1993) and am replacing the old Perko vents located on each of my stern quarters that are connected to the blower in the engine compartment. The new Perko vents are built to take a 3 1/4 vent hose rather than the 2 1/2 inch hose that connected to the old ones. I was wondering whether anyone could advise me on how I can adapt the new 3" vents to accept the 2 1/2 inch hose.
When I replaced mine, I also replaced the hose, it was full of "stuff". I secured a screen over the lip of the vent with a cable tie. No more easy access for spiders.
Have you done a Google search for 3" to 2" hose adapters? You could also search on West Marine, Defender, and various hardware store websites.
abe : If all else fails, cut off the flange and mount the new ones flush on the decking. Make sure that you seal the cut hole (epoxy or varnish). Don't forget to put some window screen over that hole.
A few thoughts