Hitchcocks Forum

I have a 1937 250 S2, recently restored from a barn find. The clutch has been re-corked and works well until I put oil into the primary case, then it slips so badly that I can't even kick it over. I have checked everything for burrs and flatness and fitted uprated springs from Hitchcocks, but still the problem persists, even with the cable slacked right off. Anyone out there who can recommend a fix for me ?

What oil did you put in it?

HOW MUCH oil did you put in?


Worked before, yes? You have added unsuitable oil and or too much oil


Drain the oil, wash the plates clean in petrol, and retry with out oil...

Hi STEW......So, if I'm reading you correctly you actually ran the bike ( ie out on the road ) with the new corks/ drive plates fitted but DRY ??------Then you added the oil and the clutch now slips ??..........OK, it's been a few years now since I was regularly working with corked plates ( Grass track racing ) but I seem to remember that we always soaked them overnight in the primary oil before fitting .....I would also agree with TIM and PAPASMURF re}-- oil type and quantity...

Dry cork clutch plates work well in Ariels, they are in a separate compartment to keep the oil OUT
. If the clutch must run in oil, it might be easier to just change to another type of friction material.

Another thought (after a cup of coffee) only non-friction modified oil should be used; Automatic Transmission Fluid (ATF) preferably for Fords; more grip, or motorcycle oil which lubricates both engine and clutch; no friction modifiers.

It was always the rule that a cork clutch was either run with oil or without, and whichever way it stated was how it should stay, or it would slip.

I have an old book, ROYAL ENFIELD MOTOR CYCLES - A Practical Guide For Owners And Repairers, By C.A.A.BOOKER, Service Manager at Royal Enfield. It states that the clutch on you'r Enfield should be dry. Any oil on plates will cause slip. Lee

Thanks for all the replies guys, but, the chaincase and clutch cover has a filling hole and plug and an overflow hole with a sealing plug. The Enfield manual that I nhave for the bike says "The front chain case on Models C and S2 should be filled with oil up to the level of the overflow plug. The chain will thus be kept clean and well lubricated giving a silent and efficient drive". Also "Cork clutches grip equally well whether oily or dry and wear better when oil is present so that it is best to keep the chain case well filled with oil on Model C and S2". So looks like the chaincase should contain oil and operate without a problem. The manual doesn't actually state what type or grade of oil to use in the chaincase just specifies what to use throughout the engine. I think nI need to follow some of the advice given, strip and clean, then try with automatic transmission fluid, see how that does.

Just a thought, you say the clutch has been re-corked? I wonder if the new corks aren't thick enough and the springs simply can't exert enough pressure to grip? I'm theorising here but if you can add an extra plate (doesn't matter if it's steel or a used or new cork one,) it might bring the "stack height" as it is known nowadays, up to a point where the springs can do their job. ATF might help, and I'd use it anyway, but your problem sounds more fundamental.

REgards, Mark