SO……

[charlie_the_tuna]

2001 115TXRZ. runs like a champ but just a touch to light for the V.

[Destroyer]

Originally Posted by charlie_the_tuna

2001 115TXRZ. runs like a champ but just a touch to light for the V.

Agreed. I have a 110hp on my 16.5 Airslot. Perfect. But I would think a 150 or a 200 would be better for the V20's. Have you tried different pitch props to make sure you aren't lugging the engine at WOT?

.

[charlie_the_tuna]

the guy gave me a brand spankin' new aluminum prop with the sale. i'm 100% sure it's not optimal for the application. fact is all my numbers would improve with the right stainless prop. the other fact is with all the nickel and diming this thing has done, the boss would have my balls if i were to even think about another $400 to $500 for a new prop. maybe eventually i'll find a decent used one, but for now... my numbers, gas economy and speed will suffer.
i just keep telling myself i'm back where i belong. who gives a crap how fast i get there?!?

[Destroyer]

Originally Posted by charlie_the_tuna

the guy gave me a brand spankin' new aluminum prop with the sale. i'm 100% sure it's not optimal for the application. fact is all my numbers would improve with the right stainless prop. the other fact is with all the nickel and diming this thing has done, the boss would have my balls if i were to even think about another $400 to $500 for a new prop. maybe eventually i'll find a decent used one, but for now... my numbers, gas economy and speed will suffer.
i just keep telling myself i'm back where i belong. who gives a crap how fast i get there?!?

ok, lets get back to basics. What size prop do you have on her now (dia/pitch) and what does your engine turn at WOT?

.

[charlie_the_tuna]

We’re turning 5,200@22mph. I think the prop is 14X17. Don’t quote me on that. I’ll take a look tomorrow.

[Destroyer]

Originally Posted by charlie_the_tuna

We’re turning 5,200@22mph. I think the prop is 14X17. Don’t quote me on that. I’ll take a look tomorrow.

Book says 4500-5500 rpm @wot. So if you're running a 17P prop you're on the high side of the range.
Given that I would think it would be safe to go up to a 19P prop for testing. That will give you less rpms, but maybe more speed. 18P for a SS prop.

.

[spareparts]

that bottom paint is whats killing your speed

[charlie_the_tuna]

Yeah, the paint is a big part of it. The aluminum prop is an issue as is the size and pitch. I don’t know how to figure out the right numbers and if I did… I couldn’t afford it anyway. When I pull her out, I’m gonna hit the hull with a super stiff brush and take off as much paint as I can. Then I’ll figure out what my next move will be.

[spareparts]

at those speeds, stainless steel isn't any help, its really not until you get into the 50+ mph range that stainless helps, its more of an issue with prop design than material. If you luck up and find one of the old straight back blade, black painted factory Yamaha stainless steel props, they are great for lower powered boats. You can pick them up used pretty cheap because they aren't pretty like other stainless props, check with your local prop shop. To give you an idea, my 17 Sea Hunt has a 150 Johnson V6 on it, spinning a 19 pitch prop 5200 rpm, I'm only getting about 44 mph out of it. It should be a rocket ship, but its not. The previous owner was a diving company, and they left teh boat in a slip with ablative paint. Its had a bunch on it. I've hit it with 80 grit on a DA, paint remover, and a pressure washer. I've got about 50% of teh paint off, and it helped(wouldn't break 40 to begin with). Every time I haul it out, I hit the bottom with the pressure washer, between that and sand bars, I'm slowly removing the paint. i need to crawl under it with a scraper at this point.

[Destroyer]

Originally Posted by spareparts

at those speeds, stainless steel isn't any help, its really not until you get into the 50+ mph range that stainless helps, its more of an issue with prop design than material. If you luck up and find one of the old straight back blade, black painted factory Yamaha stainless steel props, they are great for lower powered boats. You can pick them up used pretty cheap because they aren't pretty like other stainless props, check with your local prop shop. To give you an idea, my 17 Sea Hunt has a 150 Johnson V6 on it, spinning a 19 pitch prop 5200 rpm, I'm only getting about 44 mph out of it. It should be a rocket ship, but its not. The previous owner was a diving company, and they left teh boat in a slip with ablative paint. Its had a bunch on it. I've hit it with 80 grit on a DA, paint remover, and a pressure washer. I've got about 50% of teh paint off, and it helped(wouldn't break 40 to begin with). Every time I haul it out, I hit the bottom with the pressure washer, between that and sand bars, I'm slowly removing the paint. i need to crawl under it with a scraper at this point.

Soda blasting. Messy and it costs a bit but it works wonders for paint removing without hurting the glass underneath.

.