prop rating vs crank rating

[rockyrude]

I've got a chance to repower my thunderbird cheap. The boat is rated 135 max and I've got a chance to pick up a 140 cheap. I'm not worried about the boat since I just rebuilt everything. Is the 140 prop or crank rated? What would the true hp be? The motor I'm looking at is a 78

 

[crb478]

Re: prop rating vs crank rating

a 78 would be rated at the crank, it probably has about 125 hp at the prop

 

[kenmyfam]

Re: prop rating vs crank rating

Crank rated but be careful if you are exceeding the max HP on your boat. Especially if you have an accident out there. Even 1hp over the max and the insurance company have a reason not to cover you.