200hp yamaha on 16,5 ft not as fast as I thought ....

[deejaycee_2000]

I ran my 16.5 ft raven with 200hp yamaha ... thought I would get at least 75mph out of it but, nothing more than 55 mph ..... fitted with 19p stainless prop ...... I geuss the hull is deeper than I thought, engine runs great though ...... any thoughts? .....

 

[kenmyfam]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

I can only get 46 mph out of a 140 hp on the same size boat (doral though) fast enough for me but I know that's never the case with you from reading your posts !!! LOL

 

[tashasdaddy]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

you know we hate whale tails. we shouldn't have to tell you setup is everything. you sure the wife didn't put a governor on it to keep you from flipping it.

 

[deejaycee_2000]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

hahahahahaha, my setup is perfect, I'll try a couple of different props though ..... hehehe the wife will be to scared she breaks a nail ...

 

[Texasmark]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

Boat have a pad? Got any setback built into the rear of the hull......like fore to aft, the keel (if it had one) stops 8 inches or so before you get to the transom.....usually only get that if you have a pad? What are your WOT rpm's?

Gonna guess that at 55 your whalestale is up out of the water since your engine should be trimmed out pretty good.

Lotta boat there. Regardless of the above, I think you are overoptimistic about your top speed......maybe 60. (See Dhadley and Kenny have taught me what to look for d ).

Mark

 

[WillyBWright]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

"Any thoughts?"

Yeah. Hang a motor on it it's rated for before you kill somebody. :^

 

[deejaycee_2000]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

mmmm that is what I thought also Mark .... max rpm's 6000 .... I got too over exited before I saw the boat ..... thinking about finding a hydrostream for the motor ... very scarce in these parts ..... it is rated for a 130hp max ..... you know I can't do that Willy, people will look at me funny if I have a normal boat ...

 

[BF]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

shouldn't your 200 hp be able to swing more than a 19p prop?? I have a merc 150 with a 19 p prop on a 17' boat... not as deep as yours, more of a speedboat style (like glastron cvx)... performance is about the same as yours. (mid 50's and 6000 rpm)... and gets a bit wild in the last few mph.

Any chance your motor has a rev-limiter kicking in at 6K? I'd think you should be turning about a 23 p. (?)

 

[WillyBWright]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

What is the policy in South Africa about overpowered boats? Both legal and liability-wise? And I agree. You should be able to twist a 23. Question is if the hull will still be controllable over it's maximum designed horsepower/speed. Trim tabs instead of that whale tail would add significant stability and reduce drag.

Aren't there two different block sizes for 200 Yamaha's? Is that the smaller bore version? If so, I'd expect solid 60s. Bigger bore 200 might tickle the 70s.

 

[jimmbo]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

My Glastron GS180 with a 150 Fucht did 53 - 54mph with engine lifted up on transom to 3rd hole from top. That along with the built in setback the transom had raised the antiventilation plate about 3 1/3 inches above the bottem of the boat.
Try a Mercury Enertia 22 - 24 in, raise the engine up on the transom a couple of inches and see what it does. You should be able to break 60. If it starts walking, lift(not trim) the engine up some more. Add a water pressure gauge if it doesn't already have one, and keep an eye on it.

 

[05GlastronSX]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

i got a 150 merc (max for the boat) on my 17.1 foot glastron SX and i get 55-56 at 5500-5600 rpm with my STOCK 21 pitch aluminum prop trimmed high. Before next summer im getting a stainless and will hope to hit 60...im shocked that ur boat only does mid 50s. i can only imagine if i dropped a 200 merc on the back of my glastron....my advice...get rid of the whale tail and spin a bigger prop. that thing should be able to swing atleast a 23 pitch. youll gain an easy 5-8 mph with that change too i would bet...

 

[deejaycee_2000]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

thanx for the advice guys ...... willy .... lucky for us in South Africa anything goes .... our legal system is so messed up you can get away with anything .... the whale tale was on the motor when I got it, so I just left it there, but i'll take it of and try a 23p prop ...... at the moment when I go WOT it pulls the boat down to the right as if the torq is really hectic even with the motor tilted up quite a bit .....

 

[Texasmark]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

Dee, your trim tab you know, is supposed to correct that, but if you are really trimmed out, it's out of the water and doing you no good.

Boy is running a 150 merc (2 Liter) on an 18' ProCraft at 55 with 2 people and gear. Heavy boat but has all the things I mentioned above (they have a www site). Prop is 21 (Merc Laser II) and it maxes at 6000 (rated 5000-5500) and 55, but the 21 is for skiing too. Gearbox is 2:1. If it wasn't for that the prop would be a 23......just some numbers of a nother rig for comparison.

So I agree, you need to go up in pitch (since you have everything else done) and if you get the right prop, you may reduce your steering load as Walleyehed and others have indicated that different types of props have different steering torques.

Mark

 

[JasonJ]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

It looks like that hull has a good amount of deadrise to it. The more the deadrise, the slower it will be if all else is equal. I would be surprised if you get much above 60 with that hull and motor. Good luck....

 

[SaltyJB]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

I ran my 16.5 ft raven with 200hp yamaha ... thought I would get at least 75mph out of it but, nothing more than 55 mph ..... fitted with 19p stainless prop ...... I geuss the hull is deeper than I thought, engine runs great though ...... any thoughts? .....

 

[SaltyJB]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

Man I think that 55mph in a boat that size is fast enough. What max. hp is the boat rated for?

 

[deejaycee_2000]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

130hp max ......

 

[kenmyfam]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

What did you have on it before the 200 hp ?? and how did it perform with that ??

 

[deejaycee_2000]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

The boat didn't have an engine, I bought the boat without seeing it in November, and let them deliver it straight to my boat mech who put the 200hp yummie on that I bought at a auction that was at his workshop allready, so I never saw the rig before he dropped it at my house, see I thought it was an old school raven, so there was a bit of a mis-communication between me and the seller, the old school raven that was manufactured in the mid 90's is a flat highspeed speedboat similar to a hydrostream ..... oh well ...

 

[kenmyfam]

Re: 200hp yamaha on 16,5 ft not as fast as I thought ....

Do you have anything else you can try on it to compare ??