2007-2009 Yamaha F15/F20 Outboard Service Manual, Page 269Get this manual
TRBL SHTG Symptom Low compression pressure
Troubleshooting Cause Valve clearance not adjusted correctly Automatic decompression actuator malfunction Damaged cylinder head gasket Damaged valve Scratched piston Cause Checking step Adjust the valve clearanceDisassemble and check the cylinder head and power unitRefer to page 5-2 5-37 5-43 5-51
Throttle valve does not fully open
Throttle control system malfunction Air leakage (carburetor to cylinder head)
Throttle cable(s) not adjusted correctly Damaged gaskets, spacer, and intake manifold (carburetor to cylinder head)
Check and adjust the throttle cable(s)Check the gaskets, spacer, and intake manifold (carburetor to cylinder head)
3-8 3-9 4-12 5-34