WOT RPM? Top speed? tach broke?

[Grant Brown]

I have a 1987 70hp 3 cyl. Mounted on a 1972 Glastron 16 ft. I'm pretty sure it's got the stock factory prop. <br />What should the WOT be? <br />How fast should this combo go? I've clocked it at up to 36mph on a flat calm lake with my GPS. <br />The other question is why would the tach always bottom out at 1000 rpm when the engine and ignition are shut off? <br />The stator and rectifier were recently replaced/upgraded at a reliable shop, and before that the tach was totally unreliable, jumping around with no relation to actual engine RPM. Now it appears to work ok but always shows a minimum of 1000 rpm.<br /><br />Thanks<br />Grant

 

[Barnacle_Bill]

Re: WOT RPM? Top speed? tach broke?

Tachs normally stay at the rpm reading it was at when the motor is shut off. If you turn the key on and look at the tach before starting the motor, the tach should go to zero. If it doesn't go to zero, it needs to be replaced.