Engine troubles

[Fast Eddie]

I've never even sat on an old Norton

You’re welcome to a go on mine one day, a healthy amount more rwhp than a 961 and in the region of 150lbs lighter (depending what 961 weight figures you believe / use).

I think it’d surprise you…

 

[Stu Bodycote]

So….. a broken rocker arm bolt. Thank goodness it happened in front of the shop. I’m not sure why this would happen. I did check the rocker arm shaft and bushing for ”feel”. There might be a very slight friction when rotating the rocker arm on the shaft but I dont know if it would cause a broken bolt.
I will probably need a new adjuster ball bolt. But I’ll cross that road soon
I think I remember someone had a problem with a rocker arm bushing so I’ll look at that too.
I do feel a bit better that I’ve found the problem.
I think that I should be able to get that broken part of the bolt out too with out taking the head off. Thats good.
And the broken bolt stayed in place! Also good!!
The adventure continues…….

Awesome news...simple fix. I'd probably replace all the rocker shaft bolts, as they're easily sourced and cheap...plus you dont know why thst one snapped, maybe over torqued.

 

[Stu Bodycote]

Guys do ya think maybe over torquing of the bolts maybe ? Replace all the bolt and properly torque them.

Agreed!

 

[Stu Bodycote]

not a lot of Renaults in the USA

Count your blessings....they're bloody shite!

 

[Stu Bodycote]

You’re welcome to a go on mine one day, a healthy amount more rwhp than a 961 and in the region of 150lbs lighter (depending what 961 weight figures you believe / use).

I think it’d surprise you…

Awesome...would be well up for that!

 

[BLIGHTYBRIT/SF]

U

Awesome...would be well up for that

I was surprised when I rode my pals 750 roadster, very smooth, lots of torque,pulled in top gear rapidly from 30mph , engine rebuilt over 30 yrs ago

 

[BritTwit]

Awesome...would be well up for that!

Forget it Stu,
A 750/850 would be boring after owning a 961.
You can actually easily get replacement parts for everything on original Commandos.
No challenge at all after hunting down 961 parts.

 

[Charlotte]

Nice find, ( well if you can call it that) but well done !!

I would definitely bottom out a bolt and measure how much is still proud.

By the way, If you still have your primary open make sure the starter ring gear is secure.

Hi Cliffa
Thanks on the suggestion. Can I check the starter ring by hand?
Or carefully with a bar?

 

[Charlotte]

Awesome news...simple fix. I'd probably replace all the rocker shaft bolts, as they're easily sourced and cheap...plus you dont know why thst one snapped, maybe over torqued.

Thanks Stu
I’m on the hunt for better replacement bolts. And I think I’ve found some!!

 

[Charlotte]

His compression test showed slightly low numbers tbh, hence my recommendation of a cylinder leak down.
As a comparison, I just pulled No1 plug out of my bike..
Obviously lots of variables here, but certainly higher than the figures the OP was quoting.

These numbers are definitely better then what I saw with mine. Once everything is back together, I’ll see if I can source a leak down tester. Or maybe I shouldn’t do that…. I probably wont lose any sleep then!!

 

[Stu Bodycote]

Tolerances were all over the place chap, which is most probably why some guys have oil breather concerns and others dont. If it runs ok, leave it alone.

 

[cliffa]

Hi Cliffa
Thanks on the suggestion. Can I check the starter ring by hand?
Or carefully with a bar?

I think you'll be able to feel if it's loose, but I guess you could carefully use a lever between the ring and drive gears and see if it feels ok. It's also worth looking at these threads if you haven't seen them before.

Another clutch basket failure.

Well, Richard-7 warned us all about the possibility of failure in the rivets holding the clutch basket to the drive gear, and I've just had it happen to me. The loud noises in the primary of my 2014 961 Sport seemed like they were getting louder, so I finally pulled the primary to take a look...

www.accessnorton.com

Starter Ring Gear -- ISSUE

I'm not sure if this is a known problem or not but it is a potential problem that should be noted. The RING GEAR (the gear that the starter is driving/spinning) can come loose as it is held on with five shoulder bolts and threebond. The problem, in my opinion from an engineering view is, the...

www.accessnorton.com

Not to frighten you, more for awareness.

 

[EstuaryBoy]

And just a random workshop picture, as its a nice view. Now I can post pics, I'll probably be all over these pages in future... sorry

Oooh look Mummy! A herd of 961s in their natural habitat!!!

 

[TonyA]

So….. a broken rocker arm bolt. Thank goodness it happened in front of the shop. I’m not sure why this would happen. I did check the rocker arm shaft and bushing for ”feel”. There might be a very slight friction when rotating the rocker arm on the shaft but I dont know if it would cause a broken bolt.
I will probably need a new adjuster ball bolt. But I’ll cross that road soon
I think I remember someone had a problem with a rocker arm bushing so I’ll look at that too.
I do feel a bit better that I’ve found the problem.
I think that I should be able to get that broken part of the bolt out too with out taking the head off. Thats good.
And the broken bolt stayed in place! Also good!!
The adventure continues…….

You have probably already done this , But make sure the Rocker Arm is not seized on the shaft . The rocker arms should move smoothly. The extra force required to move the rocker might cause the bolt to break .

 

[Charlotte]

You have probably already done this , But make sure the Rocker Arm is not seized on the shaft . The rocker arms should move smoothly. The extra force required to move the rocker might cause the bolt to break .

Hi Guys
I’ll take a closer look at the starter ring gear. Its tight to the touch but I’ll use some gentle force and see if there’s any play in it.
Regrading the rockers and spindles… The one that failed is pretty smooth but there is a bit of “notchiness”. I dont think that it would be the cause because its not THAT “notchy”( imho). I havent checked the other rockers yet but I am going to.

 

[Charlotte]

Shayne,

Did you check beneath your seat for a OBD2 plug?
Before you start to make changes to, or replace anything, first try to get a OBD reader on the bike to check for error codes.
Could save you time, effort, and money.

Hi Brit
I did check for an OBD and my set doesn’t have one
Thanks for the idea.

 

[Charlotte]

A couple more things while I’m thinking of it.
I’m going to need another rocker arm adjuster bolt(with the ball at the end). Mine is a bit ”peened” over. I have Dave C looking for one too but if he doesn’t find one would anyone have access to a replacement?
Also, I was looking at my rubber fuel line that goes from the tank quick connector to the fuel rail and I was a bit surprised to see some cracking. It might worth a look on the bikes.
Thanks again for all the ideas

 

[TonyA]

A couple more things while I’m thinking of it.
I’m going to need another rocker arm adjuster bolt(with the ball at the end). Mine is a bit ”peened” over. I have Dave C looking for one too but if he doesn’t find one would anyone have access to a replacement?
Also, I was looking at my rubber fuel line that goes from the tank quick connector to the fuel rail and I was a bit surprised to see some cracking. It might worth a look on the bikes.
Thanks again for all the ideas

Ollie Thiel had rockers when I asked. He may sell an entire rocker too ?

 

[Charlotte]

Ollie Thiel had rockers when I asked. He may sell an entire rocker too ?

Thanks Tony. I’ll keep that as an option

 

[Stu Bodycote]

its interesting because the bikes sent to the US were a mixed sort

Just seen this SE on Facebook.... did all your SE's have spoked wheels, as UK models were carbon BST's?