I'm really liking the JS2 cam with my Barlow ported small valve head, my 2 into 1 exhaust, and the 35mm FCRs. Anyone with some motorcycle riding experience could ride a Norton with this cam in it. Very linear power band, and the motor goes to a steady idle almost right away after cold started in 57 degree weather. I do have to blip the throttle some and hold it for maybe 40 seconds before it sounds right to me. No chokes on the big FCRs. I am using a TriSpark ignition that might be running around 30 degrees all in. Not sure. Strobing my bike is a pain so I put it off. Anywho if I retard it any significant amount it doesn't idle as nice.
Moving the needle clip to the 3rd position from the top on the FCRs seems to be a good starting point for this motor configuration. The FCRs are from a Sudco 750-850 Commando kit. I keep forgetting to write down the needle number, but it and all the rest of the jetting is whatever Sudco uses as default for 750-850 Commando motors. My intake manifolds are modified 32mm Commando Mk2 spigot manifolds. I don't think that means a lot, but you can't buy a set done the same.
Only noise my motor makes now is the rattle of the FCR slides at idle. Otherwise it's kind of quiet for a Norton if you don't count the exhaust.
I did change my gearing a little. The previous incarnation was a 22-42 in the primary and a 19-42 gearbox to the rear wheel. I took the 22 tooth engine sprocket out and replaced it with 21 tooth and replaced the 19 tooth gearbox sprocket with a 20 tooth gearbox sprocket. Much nicer but it could just be the fact that the motor works better with the parts that are in it now.
Motor is definitely running smoother at street speeds with the lighter pistons. Rebalancing the crank is not going to be necessary for me. It could be for someone else that is more sensitive to whatever it is they are sensitive to. It's no sewing machine far eastern manufactured motorcycle. Feels like a nice running old Norton twin to me. Much nicer ride than it was previously.
Still getting accustomed to giving the big 4LS front brake the respect it requires. That thing can easily put you on the tarmac riding a relatively light bike if you grab a handful.
No regrets with the results of the project so far. It was a bit of work, and there were some user errors along the way, but I overcame all that eventually.
The JSM treatment gave the old turd a new lease on life.
