Buring Oil

I have a 75 Commando which has had new pistons, rings and a valve job. It was done by a local British Bike Shop, although they didn't know much about Commandos. The bike smokes out of both pipes, we are talking about a lot of smoke. The guy at the bike shop is very cool, but I am hoping to give him some pointers of where to start looking. Any thoughts?
Thanks,
Ed

Cool looking dudes who smoke out of both ears after a bong hit then work on a Norton with no real exprience is just buring smoke. The man should be wearing a lab coat and spectacles and clipboard in a shop that you can eat off the floor. It's your coin.

Maybe he needs to try this pipe.



Ugh, I'd find someone new or do it yourself. It's not magic.

Don't get discouraged. If you need help let us know. Where are you?

Dave
69S

I am in Phoenix, any recomendations?

AMR of Tuscon sells a lot of Norton stuff, but I can't vouch for their work. Maybe someone else can. If you need a mechanic, Delores, CO, Colorado Norton Works will do you right for a good price. Phil at Fair Spares in San Jose is a good guy. There's a guy in LA too forget his name, he's got a shop. Rabers near SF, Old Brits in WA, but he's backed up 6 mos. You're in the wrong part of the country for me, but there's no one around my area I'd trust except Leo Geoff in Memphis. Couple of guys here on the forum, Windy in TN, I think. A fellow in TX.

Personally I'd do it myself, but then I've done it, the full monty. Believe me they're not that hard, I did it in a spare bedroom and I don't have a mechanics shop, not even a drill press and mine's running perfectly as far as I can tell. But then I love fettling with all the things I need to do. My clutch pivot screw was messing up today and really affected the clutch, and when I got home, it was a piece of cake. It's something you need to do with these bikes, especially the early ones.

I'm sure someone else will pipe up.

Dave
69S

Mowog,

I can imagine you are disappointed and if your mechanic is going to rectify the problem, I would start by doing a leak down test. This give you some pointers on what is wrong? Rings not seating is one possibility, but severe smoke sounds more like badly installed valve guides. By the way properly put together with good parts and they run very clean.

Just pulled a mates newly purchased Triumph T140 apart, it smoked on one side, and found a broken oil ring, from a hamfisted piston ring install to the barrel.
Cheers Richard

I got the recommendation of the guy that did the work from AMR, I think I'll have him take it apart and send the head out for some work. I'd do it, but I am in the middle of a 20 year Austin Healey restoration (I am so busy I just can't get to it).
Ed

This thread may be of interest, are the rubber boots fitted to the inlet valve guides:

cylinder-head-off-whats-causing-this-t13080.html

Does the bike have good compression.

Smoke usually comes from the inlet side as that is where the suction is. The exhaust side of things is usually positive pressure.

Generally speaking the rings, if broken will show on a compression check, did they check/set the end gap on the rings ?.

How long can you run the engine with the oil feed line disconnected?

Valve guide seals if not fitted correctly will cause lots of smoke, i had a cheap seal "pop off" clouds of smoke from that side.