Clive
VIP MEMBER
- Joined
- Jun 9, 2017
- Messages
- 1,153
It is known that the rocker arm bearings can fail - bind up on the shaft - so it really is something you need to check otherwise the consequential damage can be a lot more expensive.
My 2017 Euro4 CR at 13500miles is one of the latest and best incarnations of the model and I seem to have been lucky with no major issues so I suppose I assumed that my rocker arms were probably ok. First symptom was a rattly noise which was new. I checked the timing chain tensioner and it was ok so I decided to pop the rocker cover and check the rocker adjustment like we need to do every 2 years.
I used the excellent CNW guide and it is fiddly but not difficult to do. On exposing the rocker arms I discovered that one of the inlet rockers was wobbling on the shaft. for those who have not looked at the setup the push rods come up through the head with an oil feed hole through the middle which feeds up through a hole in the rocker adjuster screw ball end which then feeds through a hole in the rocker into the centre on the bearings. The bearings are 2 plain bearings around 20mm outside 16mm inside and 10mm wide. they are pushed into either end of the rocker. The angle of push is a quite offset so the loading is not direct. The bearings at the one end had drifted into the rocker up against the bearing at the other end. This then blanks off the oil feed. The bearings had not seized onto the shaft my thought is that the irregular pressures and poor bearing fit had caused it to deform.
The canted rocker then started wearing the side of the mounting post, the roller, and damaged the end of the valve stem.
So really this should require new rockers, mounting block, valve. Big job. Expensive job. Hence this thread to recommend that you make sure this doesn't happen to you.
New new Norton don't have any rockers on the shelf and won't tell me if they have been updated. Thanks guys your support of the Norton owning community who helped you get the problems of the 961 sorted is just great. Don't blame Scott he's a great guy but hamstrung by the company's policy and will let me know price as soon as rockers are available. Just remember that when bikers see a 961 on the back of a recovery truck or hear that a friend of a friend's 961 is bust they can't tell if it's a TVS or G*rner....
Thiel motorsport in Germany do a refurb service and have a fantastic reputation for their engineering. I am waiting to see if they have spare rockers and can refurb.
My 2017 Euro4 CR at 13500miles is one of the latest and best incarnations of the model and I seem to have been lucky with no major issues so I suppose I assumed that my rocker arms were probably ok. First symptom was a rattly noise which was new. I checked the timing chain tensioner and it was ok so I decided to pop the rocker cover and check the rocker adjustment like we need to do every 2 years.
I used the excellent CNW guide and it is fiddly but not difficult to do. On exposing the rocker arms I discovered that one of the inlet rockers was wobbling on the shaft. for those who have not looked at the setup the push rods come up through the head with an oil feed hole through the middle which feeds up through a hole in the rocker adjuster screw ball end which then feeds through a hole in the rocker into the centre on the bearings. The bearings are 2 plain bearings around 20mm outside 16mm inside and 10mm wide. they are pushed into either end of the rocker. The angle of push is a quite offset so the loading is not direct. The bearings at the one end had drifted into the rocker up against the bearing at the other end. This then blanks off the oil feed. The bearings had not seized onto the shaft my thought is that the irregular pressures and poor bearing fit had caused it to deform.
The canted rocker then started wearing the side of the mounting post, the roller, and damaged the end of the valve stem.
So really this should require new rockers, mounting block, valve. Big job. Expensive job. Hence this thread to recommend that you make sure this doesn't happen to you.
New new Norton don't have any rockers on the shelf and won't tell me if they have been updated. Thanks guys your support of the Norton owning community who helped you get the problems of the 961 sorted is just great. Don't blame Scott he's a great guy but hamstrung by the company's policy and will let me know price as soon as rockers are available. Just remember that when bikers see a 961 on the back of a recovery truck or hear that a friend of a friend's 961 is bust they can't tell if it's a TVS or G*rner....
Thiel motorsport in Germany do a refurb service and have a fantastic reputation for their engineering. I am waiting to see if they have spare rockers and can refurb.
