Tachometer

[jasonbailey]

I've been reading up on how to select a prop. Seems to me that I need to get an accurate RPM reading at WOT. I do have a tach, but it must be bad. It registers 2700 RPM's at WOT. My boat is a 18.5' tri hull with a 75HP Chrysler. It will run about 37-38MPH (GPS reading). So I can safely assume that it is turning faster than 2700 RPM's. Should I try a new tach, or is there another place I can look to try and straighten the one I have out?

 

[roscoe]

Re: Tachometer

You can check the back of the tach to see if it has a selector switch. Has to be set to the number of poles in the stator. ( 2x the number of magnets under the flywheel)<br /><br />You can buy a tinytach.com call them, tell them what motor you have, they will send the correct tach.

 

[jasonbailey]

Re: Tachometer

Thanks for the info. When I get home tonight I'll check the back of the tach out.