Re: O ring size on pressure fitting
More like a buck-seventy-five. They are a special size, making them impossible to find outside a dealer. The ones being sold by Sierra Marine are the wrong size, so don't bother.
The part number is 301824 and the actual size is .180" ID, .437" OD, .127" thick. The numbers don't add up exactly due to the difficulty measuring a piece of rubber.
A standard -210 o-ring is .171" ID, .449" OD, .139" thick.
I have all these numbers handy because I've been trying to find an alternate source for less than $1.75 + a 20 mile trip to the dealer.