Kohler — Compression Test (Command Twins)
Testing & diagnosis · Troubleshooting
From a Kohler service manual covering: CV17, CV18, CV20, CV22, CV23, CV25, CV620, CV621, CV630, CV640, CV641, CV670…. Check it applies to your exact model before use.
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Procedure
- Perform test on a warm engine.
- Clean any dirt or debris away from base of spark plug(s) before removing them.
- Ensure choke is off and throttle is wide open during test.
- Compression should be at least 160 psi and should not vary more than 15% between cylinders.
Tools required
- Compression tester Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- At least 160 psi; not more than 15% variation between cylinders
Source: Kohler service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.