want more power

[joshbierly]

I have 1964 Evinrude 75hp Starflight with electric shift. The motor runs great, but it seems to be a little short on power. I have had to drop my prop pitch to 10.5 so I can get the RPM's up were they should be. I have it on a 20' pontoon.
After doing some reading I think I may need to do some carb work. I would like to know were to start with them. Also i have read that on a lot of older out boards the only difference between, say a 75 and a 95 hp of the same year is the carbs or a few minor things. Is there any truth to this. I would like to get enough power to pull my kids on a tube. There still little so it should not take a lot. As of now I can get them going but its just a couple of mph from being fun for them. Last is there any way to improve mpg this thing is a hog.


thank you
Josh

 

[tashasdaddy]

Re: want more power

no, the only difference is not just the carbs. porting, exhaust. your hp was measured at the power head . the new motors are measured at the prop. you have the equivilant, of a new 55 hp motor. those old motors are gas hogs, sorry.

i have a 20' ft toon, with a 2004 50 hp it burns 5 gallons an hour at wot.

my suggestion is, a used Yamaha or Kawasaki jet ski to tow behind the toon. then tow the kids with it, or to repower with a larger motor.

 

[joshbierly]

Re: want more power

Thanks for the input I just had a Polaris 650 given to me I am working on getting water ready. I am hoping that its got enough power to pull the kids. All thou I am not real sure how to hook the tube line to it.

Thank You
Josh

 

[lindy46]

Re: want more power

Wow - 75hp on a 20' pontoon should have more than enough power to pull tubers. I do it with a 35hp. How is your compression? BTW, those motors do suck the gas.

 

[joshbierly]

Re: want more power

Actually I have never checked my compression on this motor. what do you think it should be.


Thank you
Josh

 

[lindy46]

Re: want more power

100+psi and all cylinders within 10 percent of each other. 120-130 would be good.