Question about breaking in my rebuilt engine

[DennisMo]

My 1973 850 has new pistons and rings and the cylinders are newly bored oversize.
The piston to bore clearance is 4 thou as per piston spec.
The machine shop's final hone was very fine as they said the top piston ring is chrome.
(I have never seen a hone so fine)

The shop told me to ride it hard, replace the break in oil at 50 miles with new break in oil, then replace with regular oil
at 300 miles. They said that the rings should be bedded in within the first 100 miles.

Love to get your comments

Thanks

Dennis

 

[ashman]

Just ride it normally, don't labor it and don't over rev it, just ride it and don't over think it, just take it easy for the first few hundred miles, do an oil change at 500 miles or sooner with whatever oil you normally use, as they say rings bed in pretty quick.

 

[Dedubyah]

If it's just pistons and rings, I usually start it and run it for a few minutes until warm, shut it off until cold and repeat. I then ride it, giving it a good pull from 3-3500rpm to 5000 rpm in third gear then shut the throttle and coast down to 3-3500rpm. I do that for 5 minutes or so and consider it broken in,

 

[dobba99]

Don't forget to retorque the head, after the first thermal cycle. Then after 50 miles, 100, 500

 

[DennisMo]

Thanks
I have not yet checked compression but it feels good. Although I use electric starter I did stand on the kickstarter yesterday and it would not go down with just my weight.

 

[DennisMo]

I have about 100 miles on it. Will retorque on next rainy day!

 

[velo54]

Sounds like good advice from the engine shop.

 

[ashman]

Don't forget to retorque the head, after the first thermal cycle. Then after 50 miles, 100, 500

Depends on what head gasket was used, copper or fiber seems the fiber ones need a lot of retorquing, copper torque down then retorque at 500 miles.

 

[Torontonian]

Wish I had your machine shop ( If I lived in Van. ) , not a fine crosshatch , looks good though . . But I'm happy with Gord Bush , here in Toronto ( Etobicoke ) .
That said , I'm about to fire up the new J.S. motor ( outside now ) , with long rods , short pistons , the same rebore , oversized for them .
Will report back soon , a cold snowy winter over .

 

[Adam Lynam]

Check the valve clearance after re-torque of the head bolts

 

[YING]

Thanks
I have not yet checked compression but it feels good. Although I use electric starter I did stand on the kickstarter yesterday and it would not go down with just my weight.

That’s the beauty of the Estart. I weigh about 130 lbs and the kick start just laughs at me!
Mike

 

[Grandad]

I haven't been 130 Lbs for over 50 years

 

[baz]

I haven't been 130 Lbs for over 50 years

I was born 130lbs
I've been on a diet ever since!!

 

[Fast Eddie]

If I was 130lbs I’d be rich… I wouldn’t have had to spend buckets of cash building 920 / 1007 etc motors !!

 

[ashman]

That’s the beauty of the Estart. I weigh about 130 lbs and the kick start just laughs at me!
Mike

Well when I first brought my Norton new back in 76 I was a skinny chicken leg young lad, its got nothing to do in how you kick start a Norton being skinny and light weight, it's about learning the knack of kick starting a Norton, at first I found it hard but a mate who got me into Nortons told me how, but I was also use to kick starting single dirt bikes for a few years before going to a new Norton, even now at 67 years old I still have chicken legs, well at lease one now, so as I say its not how much weight you have its how you kick it that is the secret of starting a Norton, just a lot who own one just haven't learned the right knack of kicking them, and even some long term owners seem to get it wrong, a lot of my mates who owned old British bikes can't kick my Norton over without problems and yet it was easy for me when I did have a kicking leg and my motor has a lot of compression with the work done to it.

Ashley

 

[lazyeye6]

Well when I first brought my Norton new back in 76 I was a skinny chicken leg young lad, its got nothing to do in how you kick start a Norton being skinny and light weight, it's about learning the knack of kick starting a Norton, at first I found it hard but a mate who got me into Nortons told me how, but I was also use to kick starting single dirt bikes for a few years before going to a new Norton, even now at 67 years old I still have chicken legs, well at lease one now, so as I say its not how much weight you have its how you kick it that is the secret of starting a Norton, just a lot who own one just haven't learned the right knack of kicking them, and even some long term owners seem to get it wrong, a lot of my mates who owned old British bikes can't kick my Norton over without problems and yet it was easy for me when I did have a kicking leg and my motor has a lot of compression with the work done to it.

Ashley

I agree. It’s having the knack for ones own bike. I never worried about someone else being able to start my Commando; It was aligning the stars
given the body/weight/athletics. I was weighing in at 145#. You either know how or you don’t. Given that: I have electric start now. I know how to start it manually but the body and athletics aspect has slipped away. I press the button now. I'm 79. I was one of the very first cNw electric start customers. A fine piece of kit.

 

[Torontonian]

I agree. It’s having the knack for ones own bike. I never worried about someone else being able to start my Commando; It was aligning the stars
given the body/weight/athletics. I was weighing in at 145#. You either know how or you don’t. Given that: I have electric start now. I know how to start it manually but the body and athletics aspect has slipped away. I press the button now. I'm 79. I was one of the very first cNw electric start customers. A fine piece of kit.

152 now 4 me .
Mostly beers and our love for good foods .

 

[Carl H]

My 1973 850 has new pistons and rings and the cylinders are newly bored oversize.
The piston to bore clearance is 4 thou as per piston spec.
The machine shop's final hone was very fine as they said the top piston ring is chrome.
(I have never seen a hone so fine)

The shop told me to ride it hard, replace the break in oil at 50 miles with new break in oil, then replace with regular oil
at 300 miles. They said that the rings should be bedded in within the first 100 miles.

Love to get your comments

Thanks

Dennis

Norton used very course stones on the cross hatch. An old local machine shop owner used course stone with Chrome rings and OEM Norton rings had a caragraph (sp) coating on the rings to help break the rings in.

I would do like your shop told you ,Run it hard and change the oil several times . Don't idle for long and get riding after only a minute at 2000+ RPMs to warm it up after a mile or so start giving it the beans and if it feels good run it.

 

[htown16]

If you have over a hundred miles on it and its not smoking, it is 95% broken in as far as the rings and cylinder. Just ride it normally while still not running at the same throttle setting for long period or lugging or over revving.