Clutch Slipping On Kickstart After Oil Change?

@Shabuti Yes you may need a new set of friction plates. While there check the metal driving plates. If they are within tolerance clean and rough them with some emery paper. I can't remember how much you put in the primary case but its not a lot just enough to splash on the drive chain. Some of the knowledgeable people will i am sure answer that for you. On all my old bikes i used to just use Duckham's 20/50 including the primary. And gear box 80/90

 

I would have thought that removing the clutch plates and thoroughly cleaning with brake cleaner would have done the job. However I suspect proper adjustment, spring tensioning is playing a part here.

 

@Shabuti Yes if that doesn't work you will have to get the cover of clean all the plates and test with a vernier to make sure they are within the specs and width you should have a three or four spring clutch just turn the springs in half a turn at a time keeping them even. You may also have to change the springs as eventually they do weaken. And these days you can get stronger springs. Its all trial and error.

 

Firstly remove the clutch plates, clean up the friction plates with brake and clutch cleaner (or similar), clean up the plain plates and then re install the clutch, check the springs for uniformity and the correct length, if they are in tolerance then tighten up the clutch springs again to tolerance, and a nice pull action at the lever, then remove the spark plugs, this will allow you to turn the Kickstarter by hand, you then spin the engine over whilst looking at the clutch pressure plate, you will see the clutch running uneven, you adjust each of the clutch spring nuts a little at a time until the clutch runs true. The clutch runs dry, the chain case oil is only there to lubricate the chain itself, so I would advise using ATF fluid so it just touches the lower chain run, use a proper gasket and no need to use any sort of gasket sealant, it only cause issues, a little light grease will hold the gasket in place. Re fit the plugs and plug leads and start it up, it should kick over smoothly and when running, smooth gearchanges and a light clutch pull. Ride safe all from an ageing Rocker.

 

@Shabuti Mate at those miles you should be fine. You may just have to clean and reinstall. When you do if you do strip the clutch just smooth the plates were the fit into the drum if they have indents in them but I should think yours are still like new. But there are peeps on here like @Iceman and @darkman who know your bike inside out and i am sure they would be there to help with any advice you need so just get stuck in there.

 

All good advise above but also you should have a 2 to 3mm free play at the clutch lever as this can cause slip.
With the clutch outer cover off and as stated , spark plugs removed, clean and degrease the clutch plates and check they are all in there, it has been known. Check spring lengths are in spec, if not, replace. Tighten the springs evenly , you may find they need tightening more than they were before, and using the kick-start turn the engine and adjust the springs till the clutch runs with no wobbles. Cover back on, add recommended oil, may be atf , do not overfill.
Adjust clutch lever with slack. Ride.

 

When adjusting clutch play you slacken off the adjuster at the handlebars first, then remove the inspection/adjuster bung on the primary cover by the left foot peg. Inside there is a 9/16 lock nut with an adjuster screw, slacken the nut and adjust the screw out and then back in till you feel it just nip up on the pushrod, then back the screw out a 1/4 of a turn and tighten the lock nut, this gives you free play at the clutch, then adjust the lever on the bars so you have 1/8th play.

 

@darkman I knew you would be here to the rescue.