Where does the noise come from?

That is a very interesting hypothesis. I actually have my primary apart at the moment and did wonder why the gears don't fully align. Could it be a simple screw up as you suggest? I also think the fact that the three shafts are not in alignment causes uneven thrust to the scissor gear as I have wear on over 180° of the main gear collar where the scissor gear sits. If I assemble them without the spring and shake them I hear a familiar rattle.
I have ordered a new gear assembly from Ollie Thiel, so may have a play around with the old one.
Ok, back on the saddle after a necessary medical detour. Are there any details available on Oile's design? I would love to see them!!I I am a (retired) mechanical engineer and I am associated with the best private machine shop in Hawaii, may parts from the shop are in space, Nasa and Boeing are regular customers. No, there is no room for bike parts even though the owner is a big Harley and Britbike fan, it makes no business sense, BUT, with proper planning, I can get my own time on the occasional idle Lathe or Bridgeport, the only cnc that I could use was retired about 10 years ago. Modifying an existing gear is a big job, might even be impossible, The hub OD is too small to machine a reverse taper inside, it needs to be separated from the gear and reversed, most probably with water jet ( the shop has one), but I don't know how that affects the counter balance side, need to have one on hand to scan and turn into a 3d part in CAD before it can be verified. Yes, I have one in my driveway, but there are reasons it can not be opened at the time. I would really love to see Olie's design, whoever can contact him please tell him that I would gladly sign an NDA.
 
is there room to fit a belt drive from crank to clutch, leaving gears for balance shaft only?
 
is there room to fit a belt drive from crank to clutch, leaving gears for balance shaft only?
Possibly, but it would need to be very narrow so I don’t know if it would be strong enough. It would also need some tensioning mechanism I guess? Maybe a duplex or HyVo chain would work, again a tensioner is required but it could be a simpler affair.
 
Update:…
We took the primary apart down to removing the balance gear, and checking the balance gear spring. It seemed ok. I had a new spring so it was used. We also removed the clutch basket and made sure the starter bolts were tight. We also re installed the starter ring bolts with lock tight. Note…The original starter ring bolts were still tight but didn’t seem to have any thread lock on them.
We also removed the oil pump and tried to check for any play on that end of the balance shaft. That seemed fine So I think the bearing is good.
Buttoned everything back up( along with top end installation. See other thread) and started it up. Still freakishly quiet. So I guess my bike is blessed with no/very little primary noise. Hmmmm….
hopefully this is ok? Time will tell..
 
Sorry…..One more thought on the above.
Regarding the starter ring bolts. The bolts are shouldered and quite small( 6mm maybe?). Ideally the ring could be pinned along with the bolts. Richard and Dave C have done this and Richard has the drawings for the job. We didn’t have the time to get a machine shop to do the work so opted for reusing the factory bolts and adding thread locker. I think you can also get stronger bolts for the above, which would be a good idea too.
 
Sorry…..One more thought on the above.
Regarding the starter ring bolts. The bolts are shouldered and quite small( 6mm maybe?). Ideally the ring could be pinned along with the bolts. Richard and Dave C have done this and Richard has the drawings for the job. We didn’t have the time to get a machine shop to do the work so opted for reusing the factory bolts and adding thread locker. I think you can also get stronger bolts for the above, which would be a good idea too.
back to the thread topic: Again, have not open the primary case lately, but,
is it possible to just leave the balance gear alone and machine the teeth of the clutch gear off? That would be only for the width of the "balance" portion and I am sure total removal would not be required. Even if grinding was required, that would be a simpler machining operation.
 
FYI an engineer at New New Norton is now looking at this......
If this results in something that our bikes can benefit from , probably no ? It would have been wonderful if this could have been found out by the previous principal engineer at Norton ! I think I understand what they are saying and why it does not work well as it should now. The backlash spring gear should only work against the crank drive gear and not both crank and clutch simultaneously ?
 
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I just had to put my normal quiet pipes on for my MOT and it is quite a shock to be reminded of the racket coming from the engine.....
 
I just had to put my normal quiet pipes on for my MOT and it is quite a shock to be reminded of the racket coming from the engine.....
Do you mean the cacophony of acoustical "character" that the 961 emits.
 
I must remember that description to correct my neighbours at 5.45 in the morning....
I have neighbors like that too, kind of.
They didn't mind the mechanical clatter coming from my 961.
Even my Ducati 999 with Termignoni racing exhaust is acceptable to them.
Rather they were unhappy with my other neighbor's Harley that had a screaming eagle kit and exhaust.
Everyone knows when Artie comes home.:p
The moral to this story is: to avoid problems in the 'hood, have a neighbor with a Harley.
 
I have neighbors like that too, kind of.
They didn't mind the mechanical clatter coming from my 961.
Even my Ducati 999 with Termignoni racing exhaust is acceptable to them.
Rather they were unhappy with my other neighbor's Harley that had a screaming eagle kit and exhaust.
Everyone knows when Artie comes home.:p
The moral to this story is: to avoid problems in the 'hood, have a neighbor with a Harley.
Sometimes the exhaust can be too loud for every day use. Also , the way the bike is ridden and throttle blipped or revved up excessively can be problematic. I think most of us know how and when to keep it down , gentle throttle and coasting helps tremendously .
 
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I just had to put my normal quiet pipes on for my MOT and it is quite a shock to be reminded of the racket coming from the engine.....
A 961 with open megas is LOUD ! I remember the first time I heard it it at Coote's thinking I better keep at eye out for the cops. I know its way too loud for my area .
 
For my MOT the tester said they don't care now how loud it is so long as it doesn't have a label saying for track use only - which my opens do. Now how on earth am I going to sort that one out?:rolleyes:

There are big down sides to this situation but we have a shortage (not height) of Police on the streets in the UK so the chance of getting pulled for a noisy exhaust are a nat's nadgers from zero.
 
For my MOT the tester said they don't care now how loud it is so long as it doesn't have a label saying for track use only - which my opens do. Now how on earth am I going to sort that one out?:rolleyes:

There are big down sides to this situation but we have a shortage (not height) of Police on the streets in the UK so the chance of getting pulled for a noisy exhaust are a nat's nadgers from zero.

IIRC you can put a sticker, even tape, over the ‘for race use only’ stamping and that’s enough to stop the tester seeing it and failing it.

He can’t see it if it’s covered up, and he doesn’t have the authority to remove the stickers.

At least that’s how it used to be, not sure if it’s changed.
 
IIRC you can put a sticker, even tape, over the ‘for race use only’ stamping and that’s enough to stop the tester seeing it and failing it.

He can’t see it if it’s covered up, and he doesn’t have the authority to remove the stickers.

At least that’s how it used to be, not sure if it’s changed.
It's lightly etched lettering and you know how much I love polishing those beautiful long opens.....
 
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It's lightly etched lettering and you know how much I love polishing those beautiful long opens.....
How much you love polishing the long what Clive?:oops:

My shorts have a plate tack welded on the underside of each can saying ‘Not for road use’. The cans are going into an exhaust specialist next week to have some damage repaired; I’ll have these plates removed at the same time.

On a side note, I reckon the welder had the day off sick when these cans were made and the cleaning lady finished them off! I strongly suspect that she’d been drinking too!!

Where does the noise come from?
 
How much you love polishing the long what Clive?:oops:

My shorts have a plate tack welded on the underside of each can saying ‘Not for road use’. The cans are going into an exhaust specialist next week to have some damage repaired; I’ll have these plates removed at the same time.

On a side note, I reckon the welder had the day off sick when these cans were made and the cleaning lady finished them off! I strongly suspect that she’d been drinking too!!

View attachment 94318
Surprised you’re gonna bother… thought you’d have had Ollies shorties on there by now…
 
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