they usually are done by the factory. For example....Nautique calibrates all there boats at 36 mph. I am very particular in making sure both of my speedo are working and reading accurately. Like T- said I would calibrate your speedos. I ended up buying a Magellin 300. The smallest, cheapest GPS handheld you can get. The reason is because I wanted it for the MPH feature. I calibrate both speedos at what nautique does....36 MPH. Then I calibrate it at the wakeboarding speed I like which is 21.5 mph. Then its dialed. I can get both speedos on my boat within 1/2 MPH of accuracy. The old water pickups like I have only get so accurate. The MC's paddle wheels are more accurate.
|