Norton 961 Technical Service Bulletin 00014 – Crankcase Breather Modification
Download the complete PDF version using the green download button at the top right of this page for Norton Technical Service Bulletin 00014, dated 20/08/15. This factory bulletin covers excessive crankcase oil breathing into the airbox on all Norton 961 variants and details the breather modification kit and related oil system updates used to address the issue.
The bulletin identifies the symptom as more than 50 ml of oil deposited in the airbox after 500 miles of riding, with general engine tolerance build-up listed as the probable cause. It then outlines the parts included in the crankcase breather modification kit, including an air/oil separator, revised breather hoses, oil pump check valve, inline oil cooler check valve, scavenge mesh filter, revised rocker cover and airbox drain bottle components.
The procedure covers draining the oil system, installing the scavenge mesh filter, fitting the oil pump check valve, adding the inline check valve in the oil cooler line and installing the air/oil separator arrangement. Separate sections cover Commando and Dominator airbox layouts, including airbox drilling, breather spigot replacement and hose routing. The final pages explain drain bottle installation, oil refilling and oil-level checking after the work is complete.
Contents Include
- Norton 961 Technical Service Bulletin 00014
- Crankcase breathing excessive oil into the airbox
- Applies to all Norton 961 variants
- Verification threshold of more than 50 ml of airbox oil after 500 miles
- Crankcase breather modification kit parts list
- Scavenge mesh filter installation
- Oil pump check valve fitting procedure
- Inline oil cooler check valve installation
- Air/oil separator installation for Commando models
- Air/oil separator installation for Dominator models
- Airbox drain bottle and inspection bottle setup
- Rocker cover and breather hose updates
- Oil refill and oil-level checking procedure
