200 hpdi on 20ft seahawk

cj6530 · 01-26-2009, 09:48 AM

Any opinions on this combo?

Steelie Steve · 01-26-2009, 11:19 AM

I'm thinking it would be a rocket...

Mooch · 01-26-2009, 11:34 AM

Quote:

Originally Posted by Steelie Steve

I'm thinking it would be a rocket...

Yep,thats alot of engine for a 20' Seahawk.

The F150 on my 20' Seahawk pushes it up near 50. I'll bet you'd be up at 55+.

Too much of a good thing IMO. Its not all that often I can run at 50 in my boat.

luckyr · 01-26-2009, 01:46 PM

pump or prop? Prop- scary fast............. pump-still darn fast

RiverJohn · 01-26-2009, 01:54 PM

Quote:

200 hpdi on 20ft seahawk
Any opinions on this combo?

115HP a bit lower than typical
150HP Typical
200HP a bit higher than typical

My OWN opinion ?

I would order the 150HP w/20 Seahawk.

or get the 200HP with the 21 Seahawk.

Jason S · 01-26-2009, 02:34 PM

Wow propped nuts on I hit 50 On the head with a 150.

Screamer. Whats the HDPI wiegh? I would look at the 150/175 HDPI rather than a 200 IMHO.

lurking_out_loud · 01-26-2009, 03:20 PM

Go for it. Having "extra" horsepower doesn't mean you have to use it, but it sure is nice to have around when you do. I'd have no issues getting a 200 over a 150.

-lol

Raining_Kings · 01-26-2009, 03:46 PM

You might check out what the MAX HORSEPOWER sticker in the boat says. Online it only shows going up to 150hp on the 20ft, the 200 might be "too much" for that size boat.

RiverJohn · 01-26-2009, 04:20 PM

Quote:

Originally Posted by Raining_Kings

You might check out what the MAX HORSEPOWER sticker in the boat says. Online it only shows going up to 150hp on the 20ft, the 200 might be "too much" for that size boat.

Exactly !

I think it is a good idea to not "overload" the weight on a transom as well. Lighter the transom the nicer the hull sits at rest.

I have seen more than a few overloaded transoms - I feel sorry for those folks, some even have to put iron weights up front to offset things.

150hp is the charm for a 20ft.

JJsboat · 01-26-2009, 04:40 PM

Check your capacity plate and HP rating for your boat.

Do not over power more than allowed, they are there for a reason!

Sounds like way to squirrelly!! Why do you need to go that fast? The fish will be there when you get there and hopefully all your friends will be too.

If USCG happens to board you....it is called a ticket! No good service shop or dealer will over power what you are rated for the liability is way too high.

AlseaAssassin · 01-26-2009, 05:10 PM

Quote:

Originally Posted by RiverJohn

Exactly !

I think it is a good idea to not "overload" the weight on a transom as well. Lighter the transom the nicer the hull sits at rest.

I have seen more than a few overloaded transoms - I feel sorry for those folks, some even have to put iron weights up front to offset things.

150hp is the charm for a 20ft.

Is there really that much of a weight difference between a 150 and a 200? I bet they have the same size block just difference displacement.

Jason S · 01-26-2009, 05:14 PM

Tow things. No capacities plate on my 20ft Seahawk. So no problems there at all. Not required nor is level floatation on a 20+ ft boat.

Also wieght of the 200HDPI is 475#, the F150 Fourstroke is 466#. No difference there. I say go for it. I am running a big 18P wheel on mine. Can hit right at 50MPH with a wind ripple. Flat calm it is a little slower.

That motor spins slower bet you'll be running 21P prop for mid 50's. But again is it worth it? I say go for it. 150 is about perfect the 200 will just be fun.

Beware mine chine walks a little at topped out speeds I think it has to do with the transition from the full width bottom to bracket width. Be prepared for it. Only is an issue when flying as very little boat is in the water. Have fun.

Mooch · 01-26-2009, 06:08 PM

Quote:

Originally Posted by Jason S

Tow things. No capacities plate on my 20ft Seahawk. So no problems there at all. Not required nor is level floatation on a 20+ ft boat.

Also wieght of the 200HDPI is 475#, the F150 Fourstroke is 466#. No difference there. I say go for it. I am running a big 18P wheel on mine. Can hit right at 50MPH with a wind ripple. Flat calm it is a little slower.

That motor spins slower bet you'll be running 21P prop for mid 50's. But again is it worth it? I say go for it. 150 is about perfect the 200 will just be fun.

Beware mine chine walks a little at topped out speeds I think it has to do with the transition from the full width bottom to bracket width. Be prepared for it. Only is an issue when flying as very little boat is in the water. Have fun.

That another thing to consider. The Seahawk IMO isn't really designed for speeds that 200 will likely push you. Jason talks about chine walking,mine does the same.

I can guarantee the 150 will be plenty for anything you'll ever need the 20'er to do. I can load it up with as many people and gear as will fit. The 150 has no problems getting on step and no issues with reserve power.

BugSquasher · 01-26-2009, 07:14 PM

I run a 150 Yamaha 4-stroke on my 20' 2003 NR Seahawk with offshore bracket .. got close to 48-50 MPH in the right conditions before adding a tower to the boat .. that cost 5 MPH on the top end ..

150 was plenty .. I would certainly do my homework before considering anything bigger than a 150 on the 20' version .. I always say the best place to go are the people that build it .. Check with NR directly and get their input .. let us know what they had to say.

HOGTIDE · 01-26-2009, 07:42 PM

I have the 200HPDI prop on my 23' Scout. My bare hull is about #2600 and the boat really scoots. Your 20' SeaHawk may weigh close to that amount considering the forward helm. Since the motor weighs about the same as an F150, it should ride just fine on the transom. My 200 is smooth quiet smokefree and very fast.......I would say, "Don't fear the juice."

fishorgolf · 01-26-2009, 07:57 PM

fishorgolf knows fish... knows boats... knows golf.....doesen't know this laptop I run a 225hp on my Northwest Jet 19'6" pic on member profile
will hall....... not a speed boat but it will take a speed boat to go faster.
any lap top advice on downloading pictures to gallery ?????
Have fun and be safe

Jason S · 01-26-2009, 10:41 PM

Quote:

Originally Posted by BugSquasher

I run a 150 Yamaha 4-stroke on my 20' 2003 NR Seahawk with offshore bracket .. got close to 48-50 MPH in the right conditions before adding a tower to the boat .. that cost 5 MPH on the top end ..

150 was plenty .. I would certainly do my homework before considering anything bigger than a 150 on the 20' version .. I always say the best place to go are the people that build it .. Check with NR directly and get their input .. let us know what they had to say.

Your tower should not affect it that much. I notice no difference with my tower. I can run another inch in prop with the canvas down but mine never goes down. What prop are you running? If it is the Yamaha Relience 19P that could be the problem. There are better props out there PM me so we don;t derail. But a tower should not have knocked off 5 MPH. I can hit 50 with the canvas up and tower. Hit 46.5 with 3 full grown guys (one who goes 300#), 20 tuna and about 350# of ice on board behind the Westport breakwater last year. I was only 20 gallons down on the main tank too so not like I was real light on fuel.

I am all for you trying it. I really want to know what it does. But also I have heard HDPI's are not playing well with ethanol blended fuels. This is something for you to think about and do a little research on. I know I can still find non-ethanol fuel in Washington but I think it is different for the Oregon guys so correct me if I am wrong. Do some research on that though. There is another forum or two that has a lot of info on it. Would love to see Yamaha turn up the power to 175 or 200 on that 4S platform though at that wieght.