2 Stroke Port Tutorial + RPM vs Duration Charts

[JC-SuperJet]

Excellent well written short and sweet Port Tutorial with some nice RPM versus Duration Charts.

Note that, since this was written for Motorcycles, the Blow-Down vs RPM are too low for Jetskis. Seems like Jetski Blow-Down Durations are normally around 30 degrees(?)

https://martysgarage.info/reference/two-stroke-port-duration/

Great primer for anybody looking to port their Cylinders.

 

[egbrig]

There really is very little 2t porting info directly related to jetski's, but this is good info to get started with. The real take away is the relationship between each of the working parts. People like to throw out numbers so they can sound smart, but it's not the exact port time, blow down time type things that matter as much as : if you change one aspect then you need to address how it affects the next thing in line. A good read to start!