Hello,
In searching for a second (spare) prop for my outboard, I've become overloaded with info and would really appreciate some guidance:
Glastron GS180 (18 ft.)
1999 Merc. 150 EFI
Current prop is a Michigan stainless 13" diameter x 21" pitch. This prop was on the boat when I bought it. With this setup it barely reaches 5000-5100 rpm at WOT and the boat reaches a top speed of about 58 mph with just my wife and me in the boat. Please correct me if I'm wrong, but I think WOT range for this motor is 5000-5600 rpm, which just barely puts me into the acceptable range, and wouldn't even come close to hitting 5000 with additional passengers or towing a skier. I'm concerned about "lugging" the motor.
Our boat guy was kind enough to loan us a prop to try, a Quicksilver Mirage 14" diameter x 17" pitch. With this prop, I hit 5500 rpm very easily and get a top speed of 50 mph. I didn't dare push it, but it felt like I could easily redline with this prop.
I'm thinking of switching to an aluminum prop as I'd rather replace a prop than an entire gearcase if I hit something. the 21" pitch barely gets me to the low end of WOT range, and the 17" pitch gets me to the high end of WOT very easily--it feels almost too easy. Am I correct in thinking I should go with a 19" pitch? If so, what diameter, and how will changing to a lower pitch affect fuel consumption?
Thanks for the input and I look forward to hearing from you.
John
In searching for a second (spare) prop for my outboard, I've become overloaded with info and would really appreciate some guidance:
Glastron GS180 (18 ft.)
1999 Merc. 150 EFI
Current prop is a Michigan stainless 13" diameter x 21" pitch. This prop was on the boat when I bought it. With this setup it barely reaches 5000-5100 rpm at WOT and the boat reaches a top speed of about 58 mph with just my wife and me in the boat. Please correct me if I'm wrong, but I think WOT range for this motor is 5000-5600 rpm, which just barely puts me into the acceptable range, and wouldn't even come close to hitting 5000 with additional passengers or towing a skier. I'm concerned about "lugging" the motor.
Our boat guy was kind enough to loan us a prop to try, a Quicksilver Mirage 14" diameter x 17" pitch. With this prop, I hit 5500 rpm very easily and get a top speed of 50 mph. I didn't dare push it, but it felt like I could easily redline with this prop.
I'm thinking of switching to an aluminum prop as I'd rather replace a prop than an entire gearcase if I hit something. the 21" pitch barely gets me to the low end of WOT range, and the 17" pitch gets me to the high end of WOT very easily--it feels almost too easy. Am I correct in thinking I should go with a 19" pitch? If so, what diameter, and how will changing to a lower pitch affect fuel consumption?
Thanks for the input and I look forward to hearing from you.
John