So I'm experiencing something quite different then what I'm reading on forums about switching props and here is my situation.
I have an 89 cobalt condurre 192 bowrider with a 4.3 mercruiser alpha one. The prop that was on it when I got it was a ss 3 blade 19p. After getting the engine up to snuff and everything working perfect for a season I decided I wanted to change the prop for a better holeshot. I decided on the 14x19 hustler which is aluminum because my buddy swore by it and has the same engine as I do. Anyhow , my experience has been the 3 blade was a little slow to take off but got a top speed on my boat with just me in it of 42mph at about 4300 rpm, which I feel is slow but that's another topic..well I put the 4 blade on there with the same pitch and was expecting a little lower rpm at wot with a little less top end but a lot better holeshot and handling. Well I dropped from 42mph to 31mph which I feel is huge loss and the rpm actually went up to about 4600 on my tach and felt like it was touching the limiter..so my question to my confusion is why did my rpm go up and speed get dramatically reduced.. do I need a 14x21 pitch ??
here's another story. The 3 blade ss i measured to be around 13.25 or 13.5 x19 and the 4 blade is bigger at 14x19. Before i added the new prop i put a stingray classic fin on the back and that made it useable for pulling tubes and holeshot was great compared to without it..all tests mentioned were with this installed. So should I get the 21 pitch 4 blade to better match rpm and top end or just go back to the 3 blade and be happy with what worked? Any input appreciated
I have an 89 cobalt condurre 192 bowrider with a 4.3 mercruiser alpha one. The prop that was on it when I got it was a ss 3 blade 19p. After getting the engine up to snuff and everything working perfect for a season I decided I wanted to change the prop for a better holeshot. I decided on the 14x19 hustler which is aluminum because my buddy swore by it and has the same engine as I do. Anyhow , my experience has been the 3 blade was a little slow to take off but got a top speed on my boat with just me in it of 42mph at about 4300 rpm, which I feel is slow but that's another topic..well I put the 4 blade on there with the same pitch and was expecting a little lower rpm at wot with a little less top end but a lot better holeshot and handling. Well I dropped from 42mph to 31mph which I feel is huge loss and the rpm actually went up to about 4600 on my tach and felt like it was touching the limiter..so my question to my confusion is why did my rpm go up and speed get dramatically reduced.. do I need a 14x21 pitch ??
here's another story. The 3 blade ss i measured to be around 13.25 or 13.5 x19 and the 4 blade is bigger at 14x19. Before i added the new prop i put a stingray classic fin on the back and that made it useable for pulling tubes and holeshot was great compared to without it..all tests mentioned were with this installed. So should I get the 21 pitch 4 blade to better match rpm and top end or just go back to the 3 blade and be happy with what worked? Any input appreciated