I just bought a Yamaha F40TLRD - Couple Questions

[yregna]

It is a used 2005 model made in Jan.
Just moved it onto the transom of my 16ft Smokercraft. It has tiller control. I need to buy a prop. I will use this boat for running to/from spots while bass fishing, some trolling for trout, and some pulling the kids on a donut.

What pitch prop should I buy ? d

I want to check the compression to establish a baseline. Do I need the throttle all the way open or all way shut to check the compression ? Choke ?
What range numbers for psi should I expect d ?

 

[yamamarinetech40]

Re: I just bought a Yamaha F40TLRD - Couple Questions

ok, compression should be around 115 or so, not so important long as all three are close together(10 percent, which is 15 or 20 difference) and do this with throttle open, most engines don't care, some do....choke has nothing to do with compression.....now for the prop...is there a prop on the motor? I think that's a lot of boat for this motor and you want your RPM to get up as close to 6000 as possible @ WOT....I would BORROW a 10 3/4 x 15 to see where you are and go from there, each inch in pitch will move RPM approx. 200 RPM and diam. will move it about the same....

 

[yregna]

Re: I just bought a Yamaha F40TLRD - Couple Questions

A lot of boat for this motor ? This boat is rated for 45 hp MAX. I drove it about 18 knots / Hr with the 25 hp Mercury 2 stroke.
Anyway, I will get a 15 pitch prop for it and try it out. I have no prop on it currently...