Compression Testing

[Larry Zimmer]

Just thought I would post this particularly for new-commers to CBX and general use. The manual says 170 psi for compression testing pressure. NOTE: this is for a fully warm/hot engine tested immediately after 20 miles riding. Not a idle 2 minutes. Theoretical compression for a cold (70 def F) engine would be 125 psi. If you are seeing much or anything above 130 with a truly cold engine, it is most likely carbon buildup.

While theoretically, you might calculate to see 135 'cold', this assumes 100% airflow efficiency and maximum sealing of everything. And, as always, it is temperature dependent. My comment here is primarily intended to help those who are new and see the 170 spec in the shop manual. Not going to happen on a nice 70 deg afternoon with a cold engine.

[512tr]

That's good to know