Exhaust howlers

John,

I had the same fitting issue with the right hand pipe. I ordered them from Armours and returned the right one because of a loose fit in the head. The replacement pipe was no better so I used it. The pipes are generic ones for all Norton lightweights. They have a large mounting hole for the footrest bar. The hole is bigger than the diameter of the spacers. The 350 engine is slightly higher than the 250 variant. So one size fits all- more or less. I bought some very large washers and drilled the inner holes to fit over the hexagon rod, shortened the spacers, so I could sandwich the exhaust mounting tabs between these washers. I had no issue with the kickstart arm to hit the (original) mufflers so far.

Here are the measurements for the spacers in inches ordered from the NOC spares before shortening them:

Hello John,

You are making good progress; it is recognisably a lightweight Norton in your pictures and your problems with the exhausts are well known to everyone who has ever put an exhaust on a Lightweight. Original pipes, original silencers, original spacers with original kickstarts generally fit without much aggravation but the moment you get a non-original part the fun starts. Every little bit can be 'out' and everything just has to be fettled accordingly.

Your silencers look a bit low to me which at least means your rear brake seems to clear but they might ground if you bank it over very far on a bumpy corner.

You may have to bend the right hand pipe to get a better line. Yes some suppliers say that the 250 and the 350 pipes are the same - (they are not)- but the difference is the extra half inch height of the Navigator barrel. Generally it can be forced to fit. You can flare out the pipe with a ball-pein hammer to get it a better fit in the exhaust port. But do it gently.

Your kickstart doesn't have enough offset as far as I can see but otherwise it looks the part. You really need an acetylene torch to heat it up and re-shape. Original norton ones are few and far between.

Anyway. Keep on with the good work. It will soon be firing-up the motor time.

Patrick

My exhausts are a loose fit in the cylinderhead, I got round this by wrapping aluminium foil tape around the neck of the exhaust pipe tailored to be a nice interference fit,completely inconspicuous. The tape can be removed and the proccess replicated every time the exhaust is refitted. Got it off to a fine art now.

GRAHAM

Hi john,

I have never had to re-shape a normal Jubilee or Navigator exhaust pipe. I got a set of Navigator pipes quite a few years ago from a firm in the Midlands. These pipes fitted my Navigator perfectly. I believe that this firm has either changed owners or the original owners simply ceased as more recent reports gave a VERY bad opinion of a business with a remarkably similar name- it was something like Classic British Bikes. The original owner actually had a Navigator and used his own bike for the pattern exhaust and he actually told me that the Navigator pipes were the 1/2" longer than the Jubilee -so he knew !.

The only effective method I know of re-shaping is by using the acetylene torch to heat the pipe and then gently bend as required. I did this for the pipes on the Yamton - original Yamaha front pipes cut and bent to fit the Jubilee frame and Jubilee stub pipes welded in to fit the original Norton silencers in the original position. But I did the shaping and welding before getting them re-chromed and I think they look "proper factory" . Obviously you will damage your chrome if you do try heating. I have never successfully re-shaped pipes without heat. I have tried wedging a pipe in the branch of a big tree in the garden but it didn't work. You really need proper pipe bending equipment for cold bending and even then it possibly will damage the chrome.

Patrick

Somewhere in the ether my post disappeared! anyway, here goes again, my silencer is slightly upswept, and I think this was the norm and looks better that way?

I made my own footrest spacers and kept filing until the kickstart and brake pedal cleared the silencers. I also remember doing that in my youf!

Dan's picture above looks right to me. When it is exactly in the right position the silencer only just clears the foot brake pedal when this is pressed down and it also only just clears the brake lever on the back brake plate as well. It is usually this side that gives the most aggravation-the brackets holding the silencer are handed and if you get them on the wrong side the silencer fouls on the brake assembly. Dan's bike is post 1963 so it has a different shaped silencer to the pre 1963 ones and of course each version has brackets with marginally different offsets.

Patrick

I made my exhaust brackets too! And have just spent an hour fitting a new crankcase seal, hopefully this will have ceased my Torrey Canyon impersonation! Will hopefully fire it up tomorrow after the loctite has set.

Pictures of the right hand side of my Navigator. It is the De Luxe but the exhaust is the same as the Standard

and another to show the bend in the kickstart lever

and finally the front bend