961 is back !

Stu Bodycote said:
1. Yeah, pretty vague.
2. Order from Thiel.
3. Gear change rod....Ive been modified to 14.9 hitensil studs. Cush rubbers we all know to use Talons...I suspect they've copied the material now.
4. Dielectric grease.
5. See 3.
6. Interesting...didnt know that was an issue tbh.
7. Easy that one...fit compression limiters. I said that in 2016 when I was in Engine Build.
8. Want to know more.
9. Yeah, without doubt the mapping needed refining.
10......why did they stick with those shite throttle bodies?
Click to expand...
Stu, what’s the problem with the TB’s ? Do you mean the cross passage, or something else?
 
"2) Valve train re-engineered to significantly improve engine durability from 2.5 hours on test rig to 80 hours…."

Neither of these numbers seems very impressive. Is an hour on the test rig = to significantly more than an hour of actual use?
 
TonyA said:
Nothing in there about the clutch basket ?
Click to expand...
I dont have a problem with the clutch basket as a design, for the mileages I see. The only issues I get are poor assembly pre 2016. Even in this image, regards pinning the ring gear, you can see the crap riveting going on. Those should have been replaced by the factory at time of assembly.
 

Attachments

  • 961 is back !
    1631470976461.png
    1.9 MB · Views: 103
  • 961 is back !
    EXRnGCJWoAAPkbb.jpeg.jpg
    6.2 KB · Views: 90
worntorn said:
"2) Valve train re-engineered to significantly improve engine durability from 2.5 hours on test rig to 80 hours…."

Neither of these numbers seems very impressive. Is an hour on the test rig = to significantly more than an hour of actual use?
Click to expand...
Curious if they are implying that failures on the legacy 961 valve train occurred at 2.5 hours, or just unusual ware occurred?
If they were able to cause a failure at 2.5 hours of operation, that must be one hell of a test rig/program.
Perhaps the test program is composed of just rapid valve train accelerations and decelerations.
A hard and true stress test for any valve train.
 
Well for me, it’s the primary drive clatter. When I put the standard silencers on for the mot earlier this year, I turned up at our local meet and they could hear the clatter coming before the exhaust note.
Considering we’ve heard comments that Ollie and New Norton engineers had been looking into the backlash design you would think something must have been changed. Serious interrogation needed at the NEC I think later this month. Might even take some tools with me.
 
trident sam said:
Strangely the one I owned (and my mate still owns) had no primary clatter whatsoever - maybe they filled the case with sawdust ?
Click to expand...
There is certainly a correct and incorrect way to design a backlash system.
A while ago one of the forum members discussed the design of the 961's system.
He stated that the way in which the backlash gear engaged both the driving and driven gears was all wrong.
I don't claim to understand exactly what he was proposing, but I'm sure any mechanical engineer examining the arrangement would be able to correct the design.
A qualified engineer, a little time, and money, a little testing, problem solved.
This stuff is not brain surgery.
 
I’ve heard one other 961 running in the flesh and the clatter was evident; admittedly the owner has 75k+ on the clock. My bike has very little if any primary clatter; to my ear anyway.

I don’t get it? Why such a wide variance? Assembly differences, differing component manufacturing tolerances? What else can it be?
 
Stephen_Spencer said:
I’ve heard one other 961 running in the flesh and the clatter was evident; admittedly the owner has 75k+ on the clock. My bike has very little if any primary clatter; to my ear anyway.

I don’t get it? Why such a wide variance? Assembly differences, differing component manufacturing tolerances? What else can it be?
Click to expand...
@Stephen_Spencer From the perspective of the balance shaft / backlash gear - I suspect because it employs a spring, and the tension is inconsistent.

There are people here that know more than me, but I'd believe that a backlash gear is likely quieter when it's either leading or lagging. I suspect that moving between those loads increases chatter substantially, so a poor idle likely worsens the noise.
 
Gojuu said:
@Stephen_Spencer From the perspective of the balance shaft / backlash gear - I suspect because it employs a spring, and the tension is inconsistent.

There are people here that know more than me, but I'd believe that a backlash gear is likely quieter when it's either leading or lagging. I suspect that moving between those loads increases chatter substantially, so a poor idle likely worsens the noise.
Click to expand...
Hey Gj, sorta makes sense although my tech knowledge in this area is limited - my bike idles perfectly and is quieter. Having not heard many other machines in the flesh as it were, it’s difficult to tell. The guy who I refer to with the high mileage listened to mine and said it was very quiet in his experience. He has 3 x 961’s and has worked on them extensively, so I guess he knows what he’s listening to.

Mine always stalls, but usually just once per ride - to piss me off and keep me on my toes! As I close to a stop the revs drop slowly/normally to a stable tick-over, I don’t touch the throttle again until pulling away - all good. That once per ride the revs will drop more quickly than usual and it stalls!!! I think my machine is aliiiiive and asserting it’s authority:oops:!
 
the valve train test rig figures don’t make sense, as written. Will have to await further clarification.. could be a long wait, if we can hear it above the reduced primary clatter...
 
BritTwit said:
If they were able to cause a failure at 2.5 hours of operation, that must be one hell of a test rig/program.
Perhaps the test program is composed of just rapid valve train accelerations and decelerations.
Click to expand...
With no reference to the test procedure all you know is the valve train should be longer lasting, trouble is it could be just an extra 77.5hrs at 1000 rpm or 77.5 hours at 15k rpm.
 
kommando said:
With no reference to the test procedure all you know is the valve train should be longer lasting, trouble is it could be just an extra 77.5hrs at 1000 rpm or 77.5 hours at 15k rpm.
Click to expand...
At 15K rpm. I would expect the valve train to operate safely for about 1, maybe 2 nanoseconds.
Then the inside of the motor would have a very expense collection of very small parts.
 
Stu Bodycote said:
10......why did they stick with those shite throttle bodies?
Click to expand...
My thought too.
I imagine it was to be able to claim a higher percentage of British components in the 961.
But really, you're right, they are crap.
Bite the bullet and go with Keihin, or Magneti Marelli throttle bodies and EFI already.
That will eliminate any future starting, idling, running and fueling issues.
Lord knows the 961 has enough issues to deal with, without the EFI being one of them.
 
I watched the Motorbike Show last night, and Henry Cole visited the new factory and interviewed CCO Christian Gladwell. There was specific mention of the crankshaft and clutch amongst the revised components.

For folks in the UK, you can see it here

www.itv.com

The Motorbike Show - Series 11 - Episode 5

Henry Cole is in Somerset riding a Honda Goldwing and heading to the Haynes museum.
www.itv.com www.itv.com

Or on catchup TV.
 
BritTwit said:
My thought too.
I imagine it was to be able to claim a higher percentage of British components in the 961.
But really, you're right, they are crap.
Bite the bullet and go with Keihin, or Magneti Marelli throttle bodies and EFI already.
That will eliminate any future starting, idling, running and fueling issues.
Lord knows the 961 has enough issues to deal with, without the EFI being one of them.
Click to expand...
Honestly, you guys need to do some research and see who uses Jenvey and what they can build. If you ask Keihin to build what Norton asked Jenvey to build, what do you think you’d get?.

They don’t use Keihin on Singer Porsches.
 
Gojuu said:
Honestly, you guys need to do some research and see who uses Jenvey and what they can build. If you ask Keihin to build what Norton asked Jenvey to build, what do you think you’d get?.

They don’t use Keihin on Singer Porsches.
Click to expand...
Honestly I don't know what SG told Jenvey to build, and I never owned a Porsche either.
All I know is that I never owned any EFI motorcycle with Keihin throttle bodies and injectors that was hard to start, idled poorly, exhibited wild idle when hot, or other peculiarities of the Jenvey units on 961s.

Bolting a throttle body directly to an air cooled cylinder head without a rubber insulator boot will be problematic. Especially, on an engine with not insignificant vibration.

Possibly, TVS has different Jenvey units on the NEW 961.
Maybe TVS asked Jenvey to supply something different, I don't know.
The V4 has Jenvey throttle bodies, but they are very different separate throttle bodies. More like the Keihin units. Maybe that is what the 961 needs?
This is all I'm getting at.
 
You must log in or register to reply here.
Back
Top