2006 SD Johnson 4 Stroke 9.9-15HP Outboards Service Manual, Page 133Get this manual
POWERHEAD TEST PROCEDURES
TEST PROCEDURES
Compression Testing
Start and run outboard until it achieves operating temperaturethen shut OFFRemove lower side coversRefer to SIDE COVER on p180Remove spark plugs Advance throttle linkage to WOTInstall compression tester's hose attachment into spark plug hole
WARNING