I have a 75 Optimax. It came with a 21 pitch prop, I found a SSone one on Craigslist, it is a Mercury Vengance it is a 14 by 19, but it does not seat all the way back into the lower unit like the other one. Is this a problem?

Thanks Tim

It does not look like it is made for your outboard. I tried a stainless steel on my 40 and it did not perform like I wanted it to, so I traded it back to the dealer for two aluminum props and have been happy. You want to make sure your motor runs in the same rpm range with the ss as with the aluminum.

I was not running in the proper range, I could only get it to 4900 rpm and the motor states it should be 5750. I went to a prop shop and he recommended a 19 pitch, but he was really pricey so I found this one on Craigslist.

Go to the Mercury website & look up the props that fit your motor