CJBROWN said:Joe, the reduced rpms at wide open are due to too much prop. Yamaha recommends 5500-6000 for their four strokes. If you're running the 13-3/4X17 that Grady tested the boat with, you may need to drop to a 15 or 16 pitch prop. Like I say, the 15x15 (it's actually 15-1/4X15) works exceedingly well, and pulls the boat up on a plane quicker. I also run a PERMATRIM and that seems to really help a lot as well. But I doubt you'll get any more speed. That seems to be about it for the F150 on these hulls.
I run the trim right at about 3 on the trim guage, only enough right bow trim-tab to level the boat. With no top up and half fuel, I can hit about 38.5 mph. Running the trim up more does nothing, down cuts the rpm and speed.
I have heard the Mercury Revolution four in the 14x16 or 17 is the ideal prop for the F150, however I was never able to put my hands on one to try it out. I studied the prop thing to death when I first got the boat hoping to get my cruise closer to 30 and top speed closer to 40. Was not able to do that so I gave up. If I want to run 30 I just bump up to 45-4700rpms, that gets it there. I also read that a four blade will drop top speed some for a better hole shot, and that they are most popular for very high speed boats, in particular, bass boats with big motors. The four blade bites better for them and gives them a higher top speed. I dunno, I doubt they're going to do those things for the deep-v and heavy Grady's.
There are other propenents for the other Merc performance props, Enertia, is one of their new ones. Might be worth a shot.
I finally decided the F150 on a 205/208 hull is just only going to do so much. The only real solution for more speed is more horsepower. I looked at pulling the yam and putting a zuki 175 or an etec 175 or 200. But the cost for a few miles an hour just didn't seem worth it. I made quite a few trips to the Colorado River lakes when we first got 'er, and there you can get some speed work in on flat water. But most of our boating has been in the ocean over the last two years and we never run at top speed or any where near it anyway. The guys that are purporting more power are running heavy, or running in calm waters. Then yeah, a 200 or 225 is going to be the ticket.
I'd be happy to ship either of you my spare prop (15x15 aluminum) if you want to pay for the cost to ship. Try it out and send it back, order yourself a new one if you like it - they run about $100. Shipping for an aluminum prop is pretty cheap, like $10 UPS ground. Let me know...I can pick up a prop box and send it out. It's very lightly scratched but still straight. I put the new one on and carry the old one in the very forward bown comparment under the bunk.
BTW, I carry a spare thrust washer, nut, and pin, just in case I need to put that spare on and happen to drop a part while hanging off the swim step :roll:
Thanks for the input Chris. I actually have a new aluminum prop (spare) but never thought about trying it to see what diference it would make in rpm's..duh!
Until recently I was considering moving up to a bigger boat but with fuel prices the way they are that's not happening.
A friend of mine has a Hydrasport 20 WA w/150 HPDI and he switched to a 4-blade. He has been very happy with it so I talked to the local prop shop guy and he recommended a 16 pitch 4-blade for my boat. Cost ~$450.00
I haven't made up my mind yet.
CJBROWN said:Greg, it probably is a black stainless. They are fairly common and a good prop. Certainly stronger than an aluminum. The down side to a harder prop is there is a greater risk to damage to the engine itself instead of the prop if you hit something. But they will take running through the mud or sand without damage. If you're prone to run aground, they'll hold up better. I think the guys that frequent shallow water or beach their boats are at greater risk. In the past two years I've touch the bottom a couple of times. The SS doesn't even take notice, the aluminum gets scratched.
All stainless props (on my F150) develop a chatter in the lower gears when in forward or reverse at 600rpms (idle). The cure is to bump the throttle to 800 or so and it goes away. I found it extremely annoying, every time I pull up to a dock the think was chattering away. I have not written Andy at SIM about it, I know they've run into it before. Its been discussed ad-infinitem on THT with all of the yamaha four strokes. I think its worse on the smaller motor though, not as common on the 200-250's.
Joe, the reduced rpms at wide open are due to too much prop. Yamaha recommends 5500-6000 for their four strokes. If you're running the 13-3/4X17 that Grady tested the boat with, you may need to drop to a 15 or 16 pitch prop. Like I say, the 15x15 (it's actually 15-1/4X15) works exceedingly well, and pulls the boat up on a plane quicker. I also run a PERMATRIM and that seems to really help a lot as well. But I doubt you'll get any more speed. That seems to be about it for the F150 on these hulls.
I run the trim right at about 3 on the trim guage, only enough right bow trim-tab to level the boat. With no top up and half fuel, I can hit about 38.5 mph. Running the trim up more does nothing, down cuts the rpm and speed.
I have heard the Mercury Revolution four in the 14x16 or 17 is the ideal prop for the F150, however I was never able to put my hands on one to try it out. I studied the prop thing to death when I first got the boat hoping to get my cruise closer to 30 and top speed closer to 40. Was not able to do that so I gave up. If I want to run 30 I just bump up to 45-4700rpms, that gets it there. I also read that a four blade will drop top speed some for a better hole shot, and that they are most popular for very high speed boats, in particular, bass boats with big motors. The four blade bites better for them and gives them a higher top speed. I dunno, I doubt they're going to do those things for the deep-v and heavy Grady's.
There are other propenents for the other Merc performance props, Enertia, is one of their new ones. Might be worth a shot.
I finally decided the F150 on a 205/208 hull is just only going to do so much. The only real solution for more speed is more horsepower. I looked at pulling the yam and putting a zuki 175 or an etec 175 or 200. But the cost for a few miles an hour just didn't seem worth it. I made quite a few trips to the Colorado River lakes when we first got 'er, and there you can get some speed work in on flat water. But most of our boating has been in the ocean over the last two years and we never run at top speed or any where near it anyway. The guys that are purporting more power are running heavy, or running in calm waters. Then yeah, a 200 or 225 is going to be the ticket.
I'd be happy to ship either of you my spare prop (15x15 aluminum) if you want to pay for the cost to ship. Try it out and send it back, order yourself a new one if you like it - they run about $100. Shipping for an aluminum prop is pretty cheap, like $10 UPS ground. Let me know...I can pick up a prop box and send it out. It's very lightly scratched but still straight. I put the new one on and carry the old one in the very forward bown comparment under the bunk.
BTW, I carry a spare thrust washer, nut, and pin, just in case I need to put that spare on and happen to drop a part while hanging off the swim step :roll:
CJBROWN said:Greg, it probably is a black stainless. They are fairly common and a good prop. Certainly stronger than an aluminum. The down side to a harder prop is there is a greater risk to damage to the engine itself instead of the prop if you hit something. But they will take running through the mud or sand without damage. If you're prone to run aground, they'll hold up better. I think the guys that frequent shallow water or beach their boats are at greater risk. In the past two years I've touch the bottom a couple of times. The SS doesn't even take notice, the aluminum gets scratched.
All stainless props (on my F150) develop a chatter in the lower gears when in forward or reverse at 600rpms (idle). The cure is to bump the throttle to 800 or so and it goes away. I found it extremely annoying, every time I pull up to a dock the think was chattering away. I have not written Andy at SIM about it, I know they've run into it before. Its been discussed ad-infinitem on THT with all of the yamaha four strokes. I think its worse on the smaller motor though, not as common on the 200-250's.
Joe, the reduced rpms at wide open are due to too much prop. Yamaha recommends 5500-6000 for their four strokes. If you're running the 13-3/4X17 that Grady tested the boat with, you may need to drop to a 15 or 16 pitch prop. Like I say, the 15x15 (it's actually 15-1/4X15) works exceedingly well, and pulls the boat up on a plane quicker. I also run a PERMATRIM and that seems to really help a lot as well. But I doubt you'll get any more speed. That seems to be about it for the F150 on these hulls.
I run the trim right at about 3 on the trim guage, only enough right bow trim-tab to level the boat. With no top up and half fuel, I can hit about 38.5 mph. Running the trim up more does nothing, down cuts the rpm and speed.
I have heard the Mercury Revolution four in the 14x16 or 17 is the ideal prop for the F150, however I was never able to put my hands on one to try it out. I studied the prop thing to death when I first got the boat hoping to get my cruise closer to 30 and top speed closer to 40. Was not able to do that so I gave up. If I want to run 30 I just bump up to 45-4700rpms, that gets it there. I also read that a four blade will drop top speed some for a better hole shot, and that they are most popular for very high speed boats, in particular, bass boats with big motors. The four blade bites better for them and gives them a higher top speed. I dunno, I doubt they're going to do those things for the deep-v and heavy Grady's.
There are other propenents for the other Merc performance props, Enertia, is one of their new ones. Might be worth a shot.
I finally decided the F150 on a 205/208 hull is just only going to do so much. The only real solution for more speed is more horsepower. I looked at pulling the yam and putting a zuki 175 or an etec 175 or 200. But the cost for a few miles an hour just didn't seem worth it. I made quite a few trips to the Colorado River lakes when we first got 'er, and there you can get some speed work in on flat water. But most of our boating has been in the ocean over the last two years and we never run at top speed or any where near it anyway. The guys that are purporting more power are running heavy, or running in calm waters. Then yeah, a 200 or 225 is going to be the ticket.
I'd be happy to ship either of you my spare prop (15x15 aluminum) if you want to pay for the cost to ship. Try it out and send it back, order yourself a new one if you like it - they run about $100. Shipping for an aluminum prop is pretty cheap, like $10 UPS ground. Let me know...I can pick up a prop box and send it out. It's very lightly scratched but still straight. I put the new one on and carry the old one in the very forward bown comparment under the bunk.
BTW, I carry a spare thrust washer, nut, and pin, just in case I need to put that spare on and happen to drop a part while hanging off the swim step :roll:
