You mean a contact tach? If it can go up to 6000 it should work. But I would not want to be holding a contact tach against the flywheel nut with the boat underway screaming at 5000+ rpm! <br /><br />If you want to check the idle rpm it's probably safe. Make sure you don't have loose clothing on to catch in the flyweel teeth. Could be a disaster.
<br /><br />If you want to check the idle rpm it's probably safe. Make sure you don't have loose clothing on to catch in the flyweel teeth. Could be a disaster.
