How to get more HP out of my Yamaha

[JustJiggin]

I got a early 90's Yamaha 40 Hp.I want to get more Hp out of it.Any suggestion on how to do this or where to look would be well appreciated.I've Looked at Hydro Tec anybody ever had any dealings with them before?I seen they got Powerheads for my motor.thinking about that.My motors on a 14' fiberglass v hull Lee boat.I want to turn it into bass boat.Thanks for any advice.

 

[JustJiggin]

Re: How to get more HP out of my Yamaha

Need some help please.

 

[JB]

Re: How to get more HP out of my Yamaha

Howdy, JJ.

Welcome to iboats.

In most cases you will get a lot more results for your bux by fine tuning the rigging of your boat and selection of prop than messing with your engine.

Do you have PT&T on your engine? Ideal trim on plane will add more speed to your boat than another 10hp without power trim.

Ideal vertical positioning of the engine on the transom is another way to reduce drag.

Is the boat ideally balanced? Is the hull squeaky clean?

I never caught any more bass with a faster boat.

 

[Silvertip]

Re: How to get more HP out of my Yamaha

Since the 40 and 50 HP Yammy share a common power head, you can get a parts list for both motors and go through them item by item. When a part number differs between the two engines, get the one for the 50. Whay you cannot do (cheaply) is change the porting on the block which is often where additional power is achieved. This is very easy for the factory to do during the manufacturing process but it takes time and money to do after the fact. When you have completed this research and priced the parts you will come to the conclusion that you would be better off selling your existing motor and replacing it with a bigger one. This question is asked all the time and the answer is generally the same. There are few exceptions. In some cases, usually with smaller motors (such as 6 top 8 HP, or 25 to 30 HP) where removal of the intake restrictor plate is all that's necessary. Don't think that's the case with your engine however. Unless you find a donor engine, these conversions are rarely worth the effort.

 

[JustJiggin]

Re: How to get more HP out of my Yamaha

Where can I find a jacking plate for a resonable price?Thanks.The reason I want it to run faster JB is so I can get places faster.

 

[deejaycee_2000]

Re: How to get more HP out of my Yamaha

You can port the motor, remove rev limiter, skim block, skim head, cut exhaust, advance the timing .... there are many things you can do to these motors, believe me .....