Topic: Clutches and graphite oil

[kslrr]

Back in the early '80's, I installed a set of Barnett clutch plates and springs in my CB350F.  It worked real nice then.  Then in the mid to late '80's I started using engine oil with graphite (made by Valvoline or STP, can't remember) because it was marketed as being for high perfomance engines and there was no warning about wet clutches.  Well as time went by, the clutch would seize up when the bike sat for as little as 2-3 days.  It would only disengage after the engine was warmed up and after several stalls putting it into 1st gear.  After sitting for 12 years, the clutch would not disengage no mater what.  I had to pri the plates apart and it still seizes after a day of not running.  So now I am thinking, did the graphite oil do this?  Or is it something else?  Any one else have this experience?  I am thinking of getting a new set since these are over 20 years old and seem to be slipping now during acceleration and the new Barnetts are probably better.

[jabbadeznuts]

Not only will you need to replace the clutch plates, but you'll also need to flush your engine to get out any and all additive residue.

[TwoTired]

The graphite has filled up the pores in the friction plates.  The clutch springs now squeeze all the oil out from between the plates making them stick together as they form a bit of a vaccum, until some oil can seep into them between the plates.  Then it slips because the oil film prevents disc to disc contact.
Not only are your friction discs contaminated, I believe your metal discs are, too.  Further, if there is any more graphite floating around in the engine/trans, it will find its way to replacement clutch disks for a repeat lesson in what-not-to-put-in-a-motorcycle-engine-with-a-wet-clutch.

Cheers,

[kslrr]

Thanks guys.  I had a feeling that is what happened TT.  I will definitly flush out the engine on the next oil and filter change and maybe wait to replace the clutch playes until after 2 or 3 flushes. 

[keiths]

I put that graphite oil in my van in 1980 and the graphite was still leaching out of every crevice of that engine for the next 12 years and over 100,000 miles.

[kslrr]

I put that graphite oil in my van in 1980 and the graphite was still leaching out of every crevice of that engine for the next 12 years and over 100,000 miles.

Not good news.  Anybody want to invest in companies that make clutch plates and oil filters.  I might be buying a few cases over the next year or so .

[Bodi]

I doubt if graphite is an issue. Barnett plates are infamous for this cold lockup which gets worse as they wear in. Sounds like normal Barnett plates to me, nothing unusual.

[TomC]

Hi kslrr
     I second what Bodi had to say. I had a CB450 with a Barnett clutch plates years ago. The clutch would get sticky. I would take the clutch apart check every thing and clean every thing. No problems ever found but the cleaning would get the clutch working again.
          TomC in Ohio

I doubt if graphite is an issue. Barnett plates are infamous for this cold lockup which gets worse as they wear in. Sounds like normal Barnett plates to me, nothing unusual.

[kslrr]

Thanks Bodi and TomC.  My dispare has been lifted by that news.  So, a good engine flush, new oil (no additives), new filter and new clutch plates and I should be good to go