gonefishin
1/2 ton status
I have a 19 foot aluminum bass boat. vt19 crestliner. It has a 115 mercury four stroke. It came with a 19 pitch 3 blade aluminum prop. It has seen 49 mph for sure, and i think i hit 51mph, but my gps was acting funny so i'm not 100% sure. that was at 6500 rpm.
Anyway i put a stainless 20 pitch laser II prop on it. when i trim up to top out now it still goes to 6500 rpm, but it is not pulling the same. It is only getting 44-45 mph now. it's almost like it is cavitating or something. It doesn't like being trimmed up. I can trim back down and lose speed, but it's still turning 6000rpm with it trimmed down. The motor pulls it fine, but i can't trim it now, so i have lost lots of speed. The holeshot is the same as the aluminum prop.
The motor rpm range is 6000-6400 rpm.
I think it may be trying to lift the bow too much or something and causing the prop to slip instead.
Also thought maybe the motor needs to be raised or lowered. It has 5 settings and it's set on the middle hole.
I found a prop shop that said they could rework it and remove some rake. Said it might fix it.
I also thought about going with a different prop. I found a 4 blade spitfire x7. it comes in either a 19 or 21 pitch. Do i need to change the pitch when going from a 3 to a 4 blade? and i think normally a 3 blade is faster, but mercury said this one is about 1.5 mph faster than the laser II that i have now.
Any advice?
Anyway i put a stainless 20 pitch laser II prop on it. when i trim up to top out now it still goes to 6500 rpm, but it is not pulling the same. It is only getting 44-45 mph now. it's almost like it is cavitating or something. It doesn't like being trimmed up. I can trim back down and lose speed, but it's still turning 6000rpm with it trimmed down. The motor pulls it fine, but i can't trim it now, so i have lost lots of speed. The holeshot is the same as the aluminum prop.
The motor rpm range is 6000-6400 rpm.
I think it may be trying to lift the bow too much or something and causing the prop to slip instead.
Also thought maybe the motor needs to be raised or lowered. It has 5 settings and it's set on the middle hole.
I found a prop shop that said they could rework it and remove some rake. Said it might fix it.
I also thought about going with a different prop. I found a 4 blade spitfire x7. it comes in either a 19 or 21 pitch. Do i need to change the pitch when going from a 3 to a 4 blade? and i think normally a 3 blade is faster, but mercury said this one is about 1.5 mph faster than the laser II that i have now.
Any advice?
