35 hp big twin

[dunk1]

I am mounting a 1957 evinrude big twin model # 25028 on my boat and have a question about the hieght. I have read in other posts here that the anti-ventelation plate should be even with the bottom of the boat. That sounds o.k. but the water inlet on the big twin is above the ventelation plate. My thinking is the water pump won't pick up any water at that hieght when the boat is on plane. Do these older motors need to be mounted a little lower than some of the newer models? Thanks

 

[CATransplant]

Re: 35 hp big twin

Yup. If you measure the length of the outboard from the place it sits on the transom to the anti-ventilation plate, you'll see that it's 17", not the 15" you normally see on modern outboards.

They ran about 2" lower in the water. That handles the water pump issue just fine, and doesn't cut down on performance. They're for a 15" transom, and that's how they should be mounted. Ignore the advice, which is meant for later designs.