Correct clamshell vent size for 86 montauk

[JohnW]

I am getting my Montauk back into shape after a few years of non-use due to children. I need to replace the clamshell vent for the bow compartment drain and do not have the old one for comparison. Does anyone have a part number or size? Thanks so much!

[Phil T]

http://www.Hamiltonmarine.com is down but I did find them at Fisheries Supply on the West Coast.

The search is for Perko Clam shell vent.

http://www.fisheriessupply.com/vents-fans-hatches-and-windows/clamshell-vents/perko

I recall it is the large size but check the screw hole measurements to the photos.