Breathing/oil burning issues.

If the head has been rebuilt and new guides put in might have cracked the head where the guides where put in and if oil is getting into the exhaust pipes then more chance being the exhaust guides, this happen to me back in the 80s when I first converted my 850 to the Featherbed I got my head rebuilt by a so called motorcycle head expert, but not a Norton expert and within two weeks of running same thing happen as you described, at first thought it was the head gasket blown but found the cracks near the guides after close inspection after removing the header pipes, could see the cracks and the oil seeping from the cracks, something to look out for, but what ever happens you need to pull the head off.
My head was repaired by another head repairer and the other expert paid for the repairs, I am still running the same head now after 38 years and have never had that problem again.
Even the experts make mistakes and hopefully its only something simple to fix.

Ashley

coomo said:

about 300 miles.Re torquing.Due to some confusion,It may not have been done(complicated)Im hoping to check in week.

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Does it have a composite gasket?

If it’s copper you’ll most likely be fine with a re torque at this mileage. If it’s composite, you’re lucky it’s not blown completely!

There are different preferences re head torquing for composite gaskets, but the general consensus (from this forum) is something like:

1. Start the bike, run for few minutes without idling / running too slowly, do not ride, let cool and re torque.
2. Short ride around the block, re torque.
3. Re torque at 50 miles.
4. And at 200.
5. And at 500.
6. And at 1000.

Mine stopped ‘crushing’ at 500 miles. But up to that I was staggered how loose the fasteners got, I started thinking the bolts were stretching, or threads pulling, or similar.

But surely your engine man told you this and gave you running it and re torquing instructions?

I'm with @texasSlick:

Make sure your oil tank is breathing properly. I had a blocked breather on a brand new tank that caused the same symptoms.

Ok guys.had chat with my engine guy.Firstly head was re torqued to spec.I was positive it wasnt anything related to engine,ie seals etc.Anyway, he drained and refilled oil, to check it wasnt overfilled.The CNW Breather was farting nicely too.He blew air threw the spigot I brazed on the front of oil tank.Initially there was some resistance.Then it cleared.It has been ticking over for few hours.No smoke at all.Waiting for break in weather for full test ride.Perhaps something blocked the spigot.Cant be sure.
I did notice some oil around the side covers few rides back.On closer inspection, Id forgot to install a new gasket on oil tank cap.Or perhaps I didnt forget, and it made its way into tank.Who the hell knows! Further updates to follow.

I have no advice to offer as I am only just starting my first restoration of a Commando. I am however interested in knowing who built the engine for you. I see no reason why you wouldn’t say, so , can I ask who built the engine for you?
I’m sure he’s probably done a great job and may now have sorted it for you. I’m looking to find people who can do this for myself ,I know of Norman White but not really anyone else.

coomo said:

Ok guys.had chat with my engine guy.Firstly head was re torqued to spec.I was positive it wasnt anything related to engine,ie seals etc.Anyway, he drained and refilled oil, to check it wasnt overfilled.The CNW Breather was farting nicely too.He blew air threw the spigot I brazed on the front of oil tank.Initially there was some resistance.Then it cleared.It has been ticking over for few hours.No smoke at all.Waiting for break in weather for full test ride.Perhaps something blocked the spigot.Cant be sure.
I did notice some oil around the side covers few rides back.On closer inspection, Id forgot to install a new gasket on oil tank cap.Or perhaps I didnt forget, and it made its way into tank.Who the hell knows! Further updates to follow.

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Hopefully you meant ticking over for a few minutes -not hours.

JOHNO23 said:

I have no advice to offer as I am only just starting my first restoration of a Commando. I am however interested in knowing who built the engine for you. I see no reason why you wouldn’t say, so , can I ask who built the engine for you?
I’m sure he’s probably done a great job and may now have sorted it for you. I’m looking to find people who can do this for myself ,I know of Norman White but not really anyone else.

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Norman White, Mick Hemmings, Pete Lovell are 3 good guys that I know of. I believe that if you used any of these guys, you’d be happy with yer mota.

Fast Eddie said:

Norman White, Mick Hemmings, Pete Lovell are 3 good guys that I know of. I believe that if you used any of these guys, you’d be happy with yer mota.

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I spoke to Norman White the other day.......... he said budget for £3500 inc vat. For rebuild........

Well, Norman doesn’t have the cheapest hourly rate for sure, but he also knows from experience what is likely to be needed to do the job right.

Norman will fit a PW3 cam (unless you force him otherwise) and will replace / repair everything that isn’t as new and will almost exclusively fit parts from AN. It’s a very different process and a very different result to only replacing what’s out of spec and then doing so with the cheapest Chinese sh*te that can be found.

Ask around the other trusted engine builders and see how prices compare, I’d be surprised if there’s much in it.

Fast Eddie said:

Well, Norman doesn’t have the cheapest hourly rate for sure, but he also knows from experience what is likely to be needed to do the job right.

Norman will fit a PW3 cam (unless you force him otherwise) and will replace / repair everything that isn’t as new and will almost exclusively fit parts from AN. It’s a very different process and a very different result to only replacing what’s out of spec and then doing so with the cheapest Chinese sh*te that can be found.

Ask around the other trusted engine builders and see how prices compare, I’d be surprised if there’s much in it.

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Thanks for the reply. I am looking to get this bike as good and as reliable as is possible, it’s going to be doing a lot of miles. It’s not worth scrimping for the sake of a few hundred quid.

JOHNO23 said:

I spoke to Norman White the other day.......... he said budget for £3500 inc vat. For rebuild........

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To be honest, I thought it would be more. I got SRM to rebuild a Triumph T100 engine about 8 years ago & I'm sure it was close to that figure, tend to blank big figures from my memory The experience these Norton guys have, IMHO, is priceless.

Somebody on this forum explained that you 'fit' parts to a British bike and 'install' parts on a Japanese bike, I can 'install' parts but my ability to 'fit' parts is limited