Rotary Engine Compression Check Instructions
Compression Check Howto
A compression reading can be taken for a rotary engine using a regular compression gauge. The check valve for the gauge must be removed however so that a reading cannot be held. The check valve can simply be unscrewed from inside the spark plug hole adaptor of the gauge.
- Remove trailing plugs.
- Block throttle wide open.
- Disconnect the crank angle sensor's electrical connector. (white clip with 4 wires running out)
- Pull EGI fuse.
- Connect gauge to plug hole.
- Depress clutch and crank for several seconds.
- Watch for even bounces, not numbers.
- Repeat for other rotor.
- Absolute values can be recorded by reinstalling the check valve.
Interpretation of readings
- 3 even bounces of at least 85 PSI is OK.
- 3 even bounces of less than 85 PSI means motor is tired.
- 2 high and 1 low = blown or weak side seal.
- 1 high and 2 low = blown or weak apex seal.
Optimum Compression Numbers
need to add