primary chain replacement

norton1973, I haven't been on the form for a while. My 73 - 850 is in need of a new primary chain. What is the procedure for replacing one. I have the shop manual, but, sometimes it's easier to ask someone that has done one recently, in case they ran into an issue that the manual doesn't quite address. Thanks

The manual pretty well covers it. Make sure you use a clutch tool. What manual are you using? The original workshop manual is available in the tech section here. Some one will surely suggest you go to a belt and others will warn not to replace it with Reynolds chain. I think CZ and Japan got positive votes.

Russ

I did this last Spring and didn't run into anything strange. I checked the alignment of the sprockets (which was fine), cleaned the clutch plates while I had it apart, and also added a Dave Comeau mainshaft seal. You may want to make sure your alternator wire is not getting chewed by the primary chain - this happened to me a long time ago - I have it ty-wrapped to the center bolt boss. The new primary chain I used was from Andover Norton now made by CZ in Czech Republic. I did need the puller for the front sprocket (which was really on there) and the clutch spring tool. I torqued the clutch center nut to 40 ft-lbs and used blue loctite on it so I wouldn't hurt the circlip behind it on the mainshaft. The 70 ft-lb torque value in the manual is considered excessive by many.

No problems over the past riding season.

Thought of a couple more...buy a new circlip and pay attention to the shims as they come off. Sometimes the shims stick to the back of the clutch and they are easy to drop. Might as well check the bearing on the clutch while you are in there.

I think that the manual covers it pretty well. Make sure to take a hard look at the clutch bearing and circlips. As long as you have the engine sprocket off you might as well change the output shaft seal.

Have you considered going to a belt drive ? I needed a chain and the clutch basket. The belt drive set up was twice the price, but it has been reliable, never leaks, never containates the clutch plates, and it dropped the rpms in 4th gear a little. I like it a lot.


Greg

This is a good opportunity to continue one small step further and tak the inner over off also to get a good look at the countershaft sprocket right behind it.

They wear out , the teeth get rounded, easy enough to put a new one on if any doubt.

By removing the inside you can verify if the inner cover is getting chewed up by the chain/sprocket. Then shim as needed.

norton73, Go to technical information section at the top of the page. Go to commando workshop companion. Now go to 1973-74 workshop categories section C. Vary helpfull, Phil