In this video I start off riding for a bit while I give a bit of background about the dyno, why, how etc, and then we do a few runs with my mint, bone-stock 2019 R125 to try and get a feel for how to actually “do” power runs (I’m not a dyno engineer, just a nutter with a welder and little respect for my own mortality) as well as *hopefully* somewhat calibrate the dyno’s readings to match the expected power output of the bike we’re testing (2019 Yamaha YZF-R125, which should have 14.7hp).

After that i ride for a bit more and try to draw some conclusions from the tests and figure out next moves. I also have a bit of a catchup on other stuff that’s been going on, and what might be going on in future.

So as you may recall in my last post I got the dyno running but had some outstanding issues, namely:

• Roller RPM sensor was glitching and showing 500000+rpm randomly
• Engine RPM was reading wrong
• MOI calculations for the roller seemed wrong

During testing I also noticed some other things:

• that at speed the entire dyno structure was “wandering”.
• the magnet on the roller wasn’t secure

Continue reading Dyno update – bugfixing →