Slipping Clutch

Hi guys,
I have a problem with my clutch slipping on my 850 MKII! about a month a go it first started to slip, so I dismantled the clutch deglazed the plates on a piece of glass that I had taped a coarse sheet of emery paper to..... then I cleaned all of the plates steel and bronze...with petrol.wiped them dry and reassembled the clutch!
The clutch was fine then for a period of about two weeks! until I did a periodic tune up on my bike.
Now! there must be more ponies in my engine which is making my clutch slip, under medium accelleration!
I am running ATF oil as the primary lubricant! as I have always...
The clutch tension and leverage is adjusted fine also.
I would be interested in comments from other Nortoners who have curree this problem, without replacing a full set of bronze plates.
Is there a heavier diaphram spring that can be installed to produce more bight on clutch... etc?
Thanks for all response.

Brewer

so what consisted of this "tune-up"

When it first slipped and you cleaned up the clutch did it appear to have gotten lubricant into it.
If yes that problem may have reoccured.
ATF is thinner than 20-50 oil and has some super lubricating features beyond regular oil. Maybe more prone to penetrating clutch.
Did you make sure to not overfill primary on your "tuneup". 200CC and no more than to bottom of fill level checking plug.
I'd check to see if ATF comes out of oil level plug on primary case. Assuming it was filled with 200CC to begin with this indicates a possible leak from the crankcase through the main bearing seal.
If lubricant level ok but still oil in clutch I'd look to see about a clutch actuator rod seal. However I don't know why this is suddenly happening unless you are leaving the bike on the side stand a lot more than you did previously instead of the center stand.
If leak from main bear seal I'd look to be sure the engine is breathing well. Excessive pressure within the crankase especially if its wet sumped could push it through.
If you need to replace main seal it can be done from the primary by piercing the metal portion of seal and threading in a couple of screws and pulling with pliers.
Just some ideas.
Good luck
Robert

Hui Gav,
The tune up was only tappet clearance adjustment, carbs cleaned and syncronised, cables lubed , rear chain adjustment... etc, just stuff like that.
I will recheck the primary oil level. I dont think the cranckshaft seal is leaking, then engine has only been used for about 8 months after a total rebuild that I did.
I dont have a sidestand, she is always parked on a centrestand.
However the clutch pressure is not great at the lever, that is why I am thinking the diaphram has lost some of its spring tension strength... Is this common.
Brewer,

You might just have the wrong stack height....possibly a thick pressure plate meant for fibre plates?? That would give you a lighter clutch at the lever, but less pressure on the spring!

I would suggest a clutch rod seal to assure gearbox oil is not migrating along the push rod and contaminating your plates. These are available from Dave Comeau as well as several Norton parts suppliers.

Regular job cleaning the clutch plates. When you put the oil back in the cases, park the bike on the sidestand to let the excess drain out of the level plug. For some reason, I have not had to do mine this year, but it is grabby pulling away.
My clutch is harder to pull in than one of those muscle building thingies for hands, always been like that.

Thanks for that avice Ron L.
Flo, are you saying that the primary oil level should be checked from the level plug, hole when the bike is on her side stand?
I have always thought that the bike should be on the centre stand or "level" when checking the primary oil level for the drain oriface.

Brewer

A slipping clutch is not characteristic of bronze plates on a Norton. They get gummed up and start to drag, making finding neutral difficult and clunking when shifting. The diaphram springs don't suddenly get weak either.

One thing to check is that the main clutch center nut has not come loose. That'll give you some very wierd clutch issues.

I kept getting the same problem of slipping clutch on my 750.
I fitted a belt drive & had no lubricant in the primary chaincase & it still started to slip after a while.
It was oil creeping down the gearbox shaft into the primary chaincase just like somone said a few pages back.
I put one of those nuts with a seal on the end of the gear shaft where the clutch bolts on & ive not had any trouble since.
It only cost about £2 or £3. well worth it.
Cheers Don

overfilling the gearbox contributes greatly to the migration of oil into the primary

I fill mine a little under the leveling plug, there is still plenty in there to slop around and lube everything