RPM Gauge??

[URDADDY]

I posted a few weeks back but here it is again.

19' ski supreme, 351W, at WOT im getting 38 mph and 2200 RPM. Last time I posted this I got a few responses. Either propped way wrong or Tach was way off. As this is a stern drive I believe it is propped correctly. Could be wrong though... But how do I check the Tach??
Thanks.

 

[concentric]

Re: RPM Gauge??

Buy ocr borrow a optical tacho.
http://www.fieldpiece.com/tachometers/srpm2
Patch a reflecting tape on the belt wheel, point the laser to tape and read correct rpm.

 

[180shabah]

Re: RPM Gauge??

First, there is a selector on the back of the tach, so it can be hooked up to different engines. Cycle it back and forth a few times, just make sure when you stop, it is in the position for a V8.

There is NO WAY you will pull 38mph at 2200rpm.