I have the full document and smaller files.
The smaller files are in the main document, But they allow a faster view of each section.
These are scanned full color files
ONAN_6-5_manual.pdf -- 69MB This is the entire manual and includes all the files below
ONAN_6-5_schematic.pdf -- 2MB
Dimensions_and_clearances.pdf -- 1.6MB
Assembly_torques_and_special_tools.pdf -- 1.8MB
Specifications.pdf -- 1.7MB
Adjustments.pdf -- 9MB
Parts_catalog.pdf -- 24MB
Troubleshooting_guide.pdf --1.8MB
Installation.pdf -- 7.5MB
Operation.pdf -- 5.2MB
Service_and_maintenance.pdf -- 7MB
The generator is a ONAN 6.5 NH series.