I like a good tool as much as the next guy but I have a cheap easy way to verify any RPM with a strobe.
I found a free app (Iphone) used to verify RPM on a record player. Adjusting the RPM on the application to match a paint/chalk mark on the crank pulley to confirm rpm. Or setting the engine RPM and matching the App to that RPM to confirm accuracy. Confirm all to the tachometer.
You could see about turns of the driveshaft or rotation speed of the alternator etc. I deleted the app but it was good for confirming that my tac was in sync with actual RPMs.
On this post topic. My bottom and assume prop were so dirty that I was only able to get to about 2600 RPM at full throttle a few years ago. definitely dragging the works down.
Brent
I found a free app (Iphone) used to verify RPM on a record player. Adjusting the RPM on the application to match a paint/chalk mark on the crank pulley to confirm rpm. Or setting the engine RPM and matching the App to that RPM to confirm accuracy. Confirm all to the tachometer.
You could see about turns of the driveshaft or rotation speed of the alternator etc. I deleted the app but it was good for confirming that my tac was in sync with actual RPMs.
On this post topic. My bottom and assume prop were so dirty that I was only able to get to about 2600 RPM at full throttle a few years ago. definitely dragging the works down.
Brent