Need help with tritoon w/150

[BigA972]

Everything I have read I should be getting around 35-40 out of my 2007 tritoon with 150 Yamaha. I think it has a 15p 3blade prop on it. This boat does stay in the water and does get some growth underwater i try to clean about once a month. But I can only get about 20-23 with two people and fuel. Does have lifting strakes on all three toons. Can anyone point me in the right direction.

 

[brotherkicksave]

Re: Need help with tritoon w/150

BigA....When you say "35-40", are you referring to MPH or Knots? Also, what type of RPM are you seeing at WOT? How does the boat sit in the water? Is it sitting low? Do you have the ability to remove the boat from the water to check to see if there is water in any of the toons???

 

[lakegeorge]

Re: Need help with tritoon w/150

Everything I have read I should be getting around 35-40 out of my 2007 tritoon with 150 Yamaha. I think it has a 15p 3blade prop on it. This boat does stay in the water and does get some growth underwater i try to clean about once a month. But I can only get about 20-23 with two people and fuel. Does have lifting strakes on all three toons. Can anyone point me in the right direction.

You should be running in the mid thirties. You need to find out what your max rpm's are in your manual, then find out exactly what size your prop is.
In order to lose 10/12 mph you would need 1 inch of groth on it, seriously, growth isn't your problem. Worse comes to worse take it to a Yamaha dealer.

 

[BigA972]

Re: Need help with tritoon w/150

BigA....When you say "35-40", are you referring to MPH or Knots? Also, what type of RPM are you seeing at WOT? How does the boat sit in the water? Is it sitting low? Do you have the ability to remove the boat from the water to check to see if there is water in any of the toons???

I am referring to MPH. RPM run 5400 at WOT. As far as sitting in the water it seems to sit ok I am new to toons. I do pull it out about once a month for fuel and cleaning I have not seen any water coming from the toons.

 

[craigmack]

Re: Need help with tritoon w/150

Try pulling up the anchor! Sorry... I couldn't resist

Can you get the numbers off the prop? If it's really is a 15p and you're seeing 5400 RPM and only getting 23 MPH then you have serious slippage. Also check where the cavitation plate is in relation to the bottom of the toons. Is the prop in good condition?

 

[BobGinCO]

Re: Need help with tritoon w/150

Also, it might help to tell us the length and weight of the boat?

 

[BigA972]

Re: Need help with tritoon w/150

It is a 25 foot. weight I think to be around 3200 plus fuel.


"you have serious slippage. Also check where the cavitation plate is in relation to the bottom of the toons. Is the prop in good condition?"

What do you mean by slippage? Prop does have a slight flat spot on the tip of one of the blades.

 

[craigmack]

Re: Need help with tritoon w/150

Slippage is the difference between the theoretical distance the prop should move through the water in 1 revolution and the actual distance moved.

Go to this link to get more info...
http://www.go-fast.com/prop_slip.htm

 

[BobGinCO]

Re: Need help with tritoon w/150

It is a 25 foot. weight I think to be around 3200 plus fuel.

Yeah, that doesn't sound good.
My 24 foot tritoon at 3,500 pounds with a 115 putting out 95 HP (because I'm 5,000 feet above sea-level) running a 3-blade 13.75 X 13 prop hits 24 MPH at 6,200 RPM (that's where my engine ought to be at WOT).

 

[Bamaman1]

Re: Need help with tritoon w/150

Let's start over. Are you using your power trim to get the nosecone out of the water? Look over the rail and see where the water's hitting the toons after the engine is trimmed to 1/2 or higher. Getting the nose out of the water is where straked boats get their speed and efficiency. Is your speedometer accurate?

How mossy are your toons? Clean them, and check the difference in speed. Be sure to carry 3M Scotch Brite pads with you so your passengers can help you clean the toons as you're swimming, etc. It's an every week job.

Is your motor at the right height? You should be able to easily see the anticavitation plate at a medium speed cruise without a bunch of splashing obstructing the view. Experimenting with props is moot unless you have the engine height right to begin with.

Will your boat ventilate (grab air) when you trim it up? It almost sounds as if your engine is down on the transom, and possibly plowing through the water.

My new 24' Bennington with the Yamaha 150 engine and a 15 pitch Reliance prop easily gets the nose out of the water, and it's running 6000 rpm's and 40 GPS mph. The engine is set in #2 hole, about 3/4" off the transom.

You're not meeting your potential unless you're running 35 mph or more.