Starter Ring Gear -- ISSUE

I mentioned this a long time ago, it happened to me.
The reason the bolts come loose and shear on some bikes and not others, is due to the factory using UK built starter motors and Taiwanese ring gears that had a very slightly different contact angle. Some bikes were quiet and some very noisey.

961Story said:

I mentioned this a long time ago, it happened to me.
The reason the bolts come loose and shear on some bikes and not others, is due to the factory using UK built starter motors and Taiwanese ring gears that had a very slightly different contact angle. Some bikes were quiet and some very noisey.

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Possibly. But from my perspective, its an engineering flaw. The shoulder bolt body doesn’t engage in both parts. One part the body the other part only the tread.

Huge mistake that often happens with juinior designers. Guilty of it myself when I was around 21yrs old. Nortons fix was to fill it with loctite. My fix was to dowel it.

Sadly, there is one more confirmed bike with this issue and another one that will be confirmed Thursday. Has all the symptoms. If you own a 961 that has not been pinned, you are driving a time bomb. Pull the primary cover and check it now. And now with norton closed. Getting parts will not be easy.

Some back history. I contacted Simon before he hated me. Nortons fix is filling the entire area around the shoulder bolts with loctite. Said its a non issue and loctite is more than enough. I have seen all the drawings for Kenny Dreers original design and it included dowels so I added dowels. Why Simon Skinner didn't is beyond me. This is one of the original threads I made that started to royally piss of Norton.

By taking your clutch basket with ring gear attached to a machine shop and masking off the bearings, you can get them to add two press fit dowels. Its a very easy job. Would have saved Norton a lot of warranty money too.

Hey Richard, you have the unnerving ability to scare the shit out of me, much like my ex wife!! Always value you input though, unlike hers!

Could you please advise which year the two bikes you a currently looking at with this fault are? Also, briefly detail the symptoms that may show this becoming an issue.

Apart from battery/starting issues, mine is running sweet as nut.

Thanks mate.

Steve

Stephen_Spencer said:

Hey Richard, you have the unnerving ability to scare the shit out of me, much like my ex wife!! Always value you input though, unlike hers!

Could you please advise which year the two bikes you a currently looking at with this fault are? Also, briefly detail the symptoms that may show this becoming an issue.

Apart from battery/starting issues, mine is running sweet as nut.

Thanks mate.

Steve

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There are no symptoms until its too late. Pull primary cover and check is best way to know. Look for broken bolts or loose ring gear. Post 2014 they are better. But trust nothing. Pull all bolts fill with loctite is nortons fix. My fix is pin it like in the picture i just posted.

Just noticed pics were removed. I posted on twitter. Find me at richardc7424

When my bike was in under warranty for burning, seeping from the cases and a whole host of other things, the service manager said to me "don't tell everybody, but I got you an upgraded clutch too". Does that mean I may be safe from the timebomb? That was 2015. Unfortunately, they didn't seem to tighten up the clutch basket retaining nut.

Another failure...