50 horse Johnson WOT

[omc man]

Hello,<br />I have a 97 50 horse Johnson on a 16x 48 aluminum semiv bass boat, just recently had a tach installed (teleflex) the prop is a stainless, without any markings other than 10 24" on one blade, my question is, until now, I never knew the rpms, just ran it at where the outboard sounded to run easy, 28 mph. Now I know that 28 mph is 5500 rpms, I pushed it to see how far it would go, went to 6500 rpms and never cut out, motor fully trimmed down and a light load. I want to know one, what is the acceptable rpms and what I should do to get them into that range, even though it was running fine at 6500rpm, I'm sure that is way too many.<br /><br />Thanks

 

[Solittle]

Re: 50 horse Johnson WOT

omc man - 6500 is way to high for that motor. Take the prop to a prop shop and describe what you have and what it is doing. They will size your present prop for you and recommend a course of action. They might be able to rework your prop to get the rpms down or recommend a new prop with a larger pitch. Until you do this I would not run that motor over 5500 rpm.

 

[Barnacle_Bill]

Re: 50 horse Johnson WOT

I don't think any prop man can rework your prop to work. Just a quick check shows that should have a 13" prop on it. If that 10 24" is the size of that prop, its way off. I think you will be pleasantly surprised with the performance of the right prop on it.