What Did You Do With Your Commando Today?

[Dellis]

Dave,
That happened to me as well when the cable snapped and I did exactly what you did. Hottest day in July on Friday the 13 in Dover Ontario.
1 hour latter I was back on the road. Bit of PIA.
No help from your members of the NOC available in your location?
Good luck.
Tom

Hi Tom,

I’ll be good RGM will get one here for Tuesday. And I’ve sorted the sticking slide with some wet and dry. I filled the bottom of the carb with baby wipes so I picked up any debris. I am a member of the NOC and I’m sure help would be there if I needed it. It good being part of a community that you know will help you if you need it.

Dave

 

[Ron Hulton]

A picture is worth a thousand words. Sadly , no answers . Just waiting for Concours to recommend the correct JB Weld .

This is the Left side and the second time that the top ring has broken . The first time , 3 years ago the top ring broke and spit out about 2 inches of ring out the exhaust . This time 1/2 of the ring is gone . No damage to the bore either time .

New pistons to be ordered in the morning.

 

[nortonmargie]

I went out in garage and looked at bikes. I had been on a trip so no bikes ran for a month. I am planning to do a club run on Norton next week so needed to get Norton out for a test run. I hadn't run one of the modern Triumphs for a month and a half. I decided I needed to get both Norton and Triumph out. Checked Norton over and found the gearbox had been leaking again. There has been an intermittent gearbox leak for some time and I can't figure out where it is coming from, despite using baby powder trick and strong light. Refilled gearbox with 90 weight, started up bike and rode about twelve miles. Norton ran well. Went back to garage, parked Norton, checked oil and state of charge - both good. Got the Triumph out and rode to brunch with some people and then to a yarn shop. Yarn shop? I iz a girl, after all...

 

[cliffa]

I went out in garage and looked at bikes. I had been on a trip so no bikes ran for a month. I am planning to do a club run on Norton next week so needed to get Norton out for a test run. I hadn't run one of the modern Triumphs for a month and a half. I decided I needed to get both Norton and Triumph out. Checked Norton over and found the gearbox had been leaking again. There has been an intermittent gearbox leak for some time and I can't figure out where it is coming from, despite using baby powder trick and strong light. Refilled gearbox with 90 weight, started up bike and rode about twelve miles. Norton ran well. Went back to garage, parked Norton, checked oil and state of charge - both good. Got the Triumph out and rode to brunch with some people and then to a yarn shop. Yarn shop? I iz a girl, after all...

A yarn shop, what’s the story?

 

[nortonmargie]

my other hobby is knitting. Because I iz a girl. Excellent nervous habit. Small projects fit well in saddlebags and provide entertainment when on the road. Produces sweaters, gloves (for wear under leather gloves) and boot socks.

 

[concours]

A picture is worth a thousand words. Sadly , no answers . Just waiting for Concours to recommend the correct JB Weld .

This is the Left side and the second time that the top ring has broken . The first time , 3 years ago the top ring broke and spit out about 2 inches of ring out the exhaust . This time 1/2 of the ring is gone . No damage to the bore either time .

New pistons to be ordered in the morning.

Please, explain.

 

[marshg246]

A yarn shop, what’s the story?

No picking on Margie - hard to get female members Besides, she rides a Commando many more miles than a lot of male members, including me.

 

[CanukNortonNut]

Please, explain.

It happened to me, where the top blew out on the piston top and my ring was getting spit out in little chunks, ( on the right cylinder). My 74 had 70K mikes on it since the last time I was in there. I pulled it out for a rebuild. I have a 73 850 engine now as a stop gap engine to keep my bike on the road. Ron's piston looks a lot worse than mine but I lost 1/3 of the top piston ring and the L/H piston had the top ring split in three sections but still in the groove. No damage to the cylinder bore but I went +0.020 on the bore and new pistons and Con Rods.


I'm not sure that it is due to the type of piston? Mine has AE on inside of piston.
I blame it on high mileage.

 

[marshg246]

Checked Norton over and found the gearbox had been leaking again.

Check the neutral switch.

 

[concours]

It happened to me, where the top blew out on the piston and my ring was getting spit out in little chunks, ( on the right cylinder). My 74 had 70K mikes on it when I pulled it out for a rebuild. I have a 73 850 engine now as a stop gap engine to keep my bike on the road. Ron's piston looks a lot worse than mine but I lost 1/3 of the top piston ring and the L/H piston had the top ring split in three sections but still in the groove. No damage to the cylinder bore but I went +0.020 on the bore and new pistons and Con Rods.

I can clearly see why the piston was damaged.

I was asking Ron Hulton about the JBWeld comment.

 

[nortonmargie]

Check the neutral switch.

thank you! Never would have thought

 

[CanukNortonNut]

I can clearly see why the piston was damaged.

I was asking Ron Hulton about the JBWeld comment.

There might have been some tongue in cheek going on there.

 

[Fast Eddie]

A picture is worth a thousand words. Sadly , no answers . Just waiting for Concours to recommend the correct JB Weld .

This is the Left side and the second time that the top ring has broken . The first time , 3 years ago the top ring broke and spit out about 2 inches of ring out the exhaust . This time 1/2 of the ring is gone . No damage to the bore either time .

New pistons to be ordered in the morning.

Bummer !

Twice in the same bore is intriguing.

Do you perhaps have a wear or carbon ridge in the bore interfering with the ring?

Thats a lot of unpleasant looking carbon on top of that piston…

 

[daveforty]

A 110m ride around the Brecon Beacons. The local VMCC has a summertime riding 'task' named the Cwmpass Ride; 32 waypoints to visit around mid Wales from the Brecon Beacons through the Cambrian mountains up to the southern edge of Snowdonia. I am now about half way through them having visited five places yesterday afternoon. This is at the Llywel viewing point near Sennybridge, at the SW end of the Epynt Mountain range. The red flag is up, but the road was open, and goes all the way across the ranges - need to re-visit that later. Pen y Fan in the distant background. Also visited the Owls Nest at Llandovery, seems like a nice place but it was very busy so didnt stay there for long.

 

[Café au Lait]

I had a similar run in Brecon a week last Thursday in my Elise; A4059 particularly impressive as was this view point on the A4061 heading toward Rhondda and a lot of traffic before the long M4 drive back to Berkshire. I hope to repeat on my Commando when it arrives.

 

[Saber]

Good luck. Is that a GPS screen on your handlebats?

 

[Ron Hulton]

Concours : It was your suggestion several months ago to seal my gas tank around the inside of the gas cap using JB Weld . It has worked great . Just hoping you had a JB Weld to fix this

Fast Eddie : I wish i knew what caused this but i am lost . Three years ago the left side started to use oil so i pulled it down and found 2 inches of the top ring missing . The piston looked good , the cylinder bore was good . Cleaned up the bore , and installed new rings. This year it started using oil again but it ran great , idled great and believe it or not ...... it did not smoke . The left muffler was an oily film on the inside. I would sure like to know what happened but that's beyond me . Ordering new pistons today and getting the cylinder bores checked and cleaned .

 

[concours]

Concours : It was your suggestion several months ago to seal my gas tank around the inside of the gas cap using JB Weld . It has worked great . Just hoping you had a JB Weld to fix this

Fast Eddie : I wish i knew what caused this but i am lost . Three years ago the left side started to use oil so i pulled it down and found 2 inches of the top ring missing . The piston looked good , the cylinder bore was good . Cleaned up the bore , and installed new rings. This year it started using oil again but it ran great , idled great and believe it or not ...... it did not smoke . The left muffler was an oily film on the inside. I would sure like to know what happened but that's beyond me . Ordering new pistons today and getting the cylinder bores checked and cleaned .

Those images scream of insufficient ring end gap, failure triggered by an overheating event.
When the ring ends butt, and expand the slightest bit more, they can LOCK HARD.

 

[Ron Hulton]

Those images scream of insufficient ring end gap, failure triggered by an overheating event.
When the ring ends butt, and expand the slightest bit more, they can LOCK HARD.

I went back and checked my notes .. Top ring was measured at .013 " gap L .013" R with the right being ok . It was the left that went 3 years ago .

Just heard from the machine shop that has my cylinder .. Bores are straight and round and in spec for my + .020 " pistons . New Andover piston kits on their way

 

[concours]

Given the

I went back and checked my notes .. Top ring was measured at .013 " gap L .013" R with the right being ok . It was the left that went 3 years ago .

Just heard from the machine shop that has my cylinder .. Bores are straight and round and in spec for my + .020 " pistons . New Andover piston kits on their way

Given the history, I'd file an additional .002" clearance above that this time around.

JMWO