2005 tohatsu 25hp 2 stroke

[tenga]

I am running this engine on a 13ft inflatable boat.At the moment i am getting 4900 rpm(max 5500 rpm) and a top speed of 31 mph with myself and 6 gallons of fuel on board or myself,wife and child get 4600 rpm and a top speed of 26 mph with a 9.6" x 13" pitch prop.The engine cavitation plate is level with the bottom of the boat.
Do i need to change the prop and if so what pitch? will this then effect the top end speed?Also are the after market props(turning point) better than engine manufacturers ones?

 

[steelespike]

Re: 2005 tohatsu 25hp 2 stroke

Not an expert but I think I would try to improve the setup first.You may be able to raise the motor vertically, also adjust the trim for best speed.If you can raise the motor an inch you could gain a couple of miles per hour and some rpm.Be sure it pumps water as you raise it.Once you have the setup and final rpm and speed you can make a decision on a prop.Hopefully one of the pros will be along with some prop advice.Generally speaking if you need rpm you would go down in pitch.But you can also work with design thats where the pros can help.

 

[deejaycee_2000]

Re: 2005 tohatsu 25hp 2 stroke

what you can do is, buy carb gaskets for a 30hp tohatsu and replace yours with them, it will add 5hp, then trim that motor out on the highest setting and go down one by one untill you feel comfortable with the handling of the boat, then get yourself a 4-blade pro-pulse adjustable pitch prop (cheaper than a normal prop) and adjust the prop to 16 pitch .... you'll be flying ...

 

[steelespike]

Re: 2005 tohatsu 25hp 2 stroke

what you can do is, buy carb gaskets for a 30hp tohatsu and replace yours with them, it will add 5hp, then trim that motor out on the highest setting and go down one by one untill you feel comfortable with the handling of the boat, then get yourself a 4-blade pro-pulse adjustable pitch prop (cheaper than a normal prop) and adjust the prop to 16 pitch .... you'll be flying ...

Believe him, the pro-pulse did amazing things for his inflatable.

 

[tenga]

Re: 2005 tohatsu 25hp 2 stroke

I have done all i can on the engine setup i have raised the engine as far as i can by placing a 1" piece of wood between the engine bracket and transom.Any higher and i will not be able to tighten the clamp screws to the transom.

 

[deejaycee_2000]

Re: 2005 tohatsu 25hp 2 stroke

1" is perfect for the height, now set the trim position up ... there is 5 pin settings, start at the highest and go down till good ......