UNDERSTANDING PROPELLERS PART 4 - 70hp to 140hp - Group D outboards

[@KGWmegastacker]

A great insight into the ‘secret’ world of prop choices. I own a 140 Suzuki & have had trouble propping it. The dealer initially pushed me into a 4 blade prop due to how & where I use my fishing boat. I cross a few dangerous coastal bars here in Gippsland Vic & needed a good hole shot type prop. It gave me good hole shot but my top end & economy suffered greatly. I spoke to a boat mechanic who was experienced in boat racing. He recommended one of ur 3 blade 19” Stella s/s prop. It’s improved my hole shot, economy & top end speed greatly. There is a movement down here in everyone going to a 4 blade prop which ‘will fix everything’. There are these ‘experts’ going around propping peoples boats with a particular manufactures brand prop. I must be the first person I know going from a 17” pitch 4 blade to a 19” 3 blade.

[@burl_]

Awesome information from an experienced engineer. Thanks, Steve, for your outstanding service.

[@thewoodmansk5510]

I have a Johnson 140 4 stroke that from what I’ve seen was built by Suzuki. Running it on a Larson 180 sei o/b. it has a 14x21p currently with good hole shot, but I’d like to get another 10mph out of it. Am I just looking at a taller pitch or where should I be looking with regard to rake and cupping

[@jamesringler987]

What about a 60 hp Johnson 2 stroke on a light 16 ft aluminum fishing boat

[@briansweeney6216]

Watched the whole thing ..I have a 75hp Honda, aluminum fishing boat , has a 15 pitch ,wish it could go a little faster ..