850 T clutch problems

[Petrus Rocks]

850 T clutch problems- the bike lurches horribly when starting out.  There is a very abrupt friction point.  I expect the clutch is worn out but if you continue riding it, the clutch doesn't seem to  slip even on the gas.  So...should everything clutch-wise be changed?  Do you need to pull it apart to see what is worn?
The adjustment on the clutch (by the transmission) appears almost all the way in. 
The clutch components on MG cycle list as big twin.  Would these be correct for the 850-T?

[Aaron D.]

Sounds like the input hub is notched. Yes, it will require removal of the transmission, and inspection of the rest of the clutch is recommended!

[Frenchfrog]

Could well have a notched flywheel too.

[PeteS]

850 T clutch problems- the bike lurches horribly when starting out.  There is a very abrupt friction point.  I expect the clutch is worn out but if you continue riding it, the clutch doesn't seem to  slip even on the gas.  So...should everything clutch-wise be changed?  Do you need to pull it apart to see what is worn?
The adjustment on the clutch (by the transmission) appears almost all the way in. 
The clutch components on MG cycle list as big twin.  Would these be correct for the 850-T?

I have mentioned this in the past and got pilloried for it but its worth a try, nothing to loose at this point.
Remove the inspection plug, take a can of WD40 and tape the spray tube to the nozzle. Then start the engine and while working the clutch lever, flood the clutch with WD40 trying to aim at the hub. Do it over dirt or gravel as a lot black mess will drip out of the housing.
If it fixes the symptoms it should  last a few thousand miles, maybe a season if you have other bikes to ride. The clutch will regain normal function after a mile or two.

Pete

[Antietam Classic Cycle]

It may just have Surflex clutch plates in it. I made the mistake of putting those in my '71 Ambassador and they never were "right". Grabby from the start and it only got worse. When I replaced them, they had destroyed the hub - all in about 20k miles.

[PeteS]

For sure Surflex are grabby. Blew up my Norton gearbox with a first generation Surflex. Later versions are not as bad. I am running one now but only half the plates are Surflex. Not an option on a Guzzi I guess.

Pete

[Petrus Rocks]

Thanks Pete,Aaron, and Frenchfrog. I'll try Pete's suggestion when the rain lets up.  This is a customer's bike.  It hadn't run for over two years.  Did a lot of electrical fixing/ replacing/wiring up new switches.  Got it running and I attempted to release the clutch-damn near ran into my truck when it lurched forward.  I also notice a rattle prob from the throwout bearing when clutch is puled in.  It's not consistent though.  Quieted  down after a bit. 
AS I want to get on with my other projects I don't want to tackle this until later in the year.

[fotoguzzi]

 The rattle might be normal.
 Mineral spirits are recommended over WD40. Plug the drain hole and pour a bunch in then work the clutch.

[PeteS]

Mineral spirts might clean debris better but if the problem is a notched rusty hub I think WD40 is the better option. It has no lasting effect on clutch friction. I have used it on brake rotors to protect them the road salt. WD40 is burned off with the first couple applications of the brakes. May sound crude but it has allowed me to continue riding the LeMans without having to yank the gearbox out.

Pete

[Chuck in Indiana]

I hope you like seafood, because a crab is in your future.. 

[lucky phil]

I hope you like seafood, because a crab is in your future.. 

Very droll Chuck, very droll 

Ciao

[Road Rocket]

 I like Pete’s WD40 trick…..Have you nay sayers tried it?

[lucian]

I did try it with mineral spirits when my LMIII started the same behavior. The first time I flushed it it lots of filthy black stuff drained out presumably friction pad material and maybe a bit of oil. It did actually improve the clutch grabbing but only very briefly and it would return very unpredictably and at the worse possible times like when leaving a light in traffic. I think the little improvement was due to the flush cleaning some crud out of the flywheel splines however there is nothing it will do to restore a notched center hub.  Not only was my hub very notched but also discovered where the gear oil leak was , Tranny input seal.  As Chuck stated , a crabbing of the frame and clutch inspection is the right way to go. While your in there, replace rear engine seal and tranny input/output seals and jb weld the cam plug. Also upgrade the clutch push rod plunger with the double o ring one and replace push rod cone seals. I am happy with the SDTech plates and definitely get rid of the oem shallow spline hub[4mm] and plates and bet the newer deep spline alternative 5mm. I also went with lighter clutch springs and it lightened the pull noticeably.  I would also recommend replacing flywheel and clutch bolts and locks and the hub retaining nut.  My guess is you will find a hub that looks like this and hopefully the flywheel spline will be ok but maybe not especially if you put it off too long.
   

[moto-uno]

  Glad to see you had good luck with the lighter springs , I wasn't so lucky on my built Le Mans 2 .
  I was also lucky enough to have a machinist make a broach (sp?) tool and he re-cut the splines
  in the flywheel ( nice because it had been previously lightened ) . Peter

[theoneandonly]

i flush clutches out with brake cleaner , plug drain as above , run engine, operate clutch. flush it  a couple of times. if it gets better it may be oil contamination . if it doesn't it may be time to strip. i use brake cleaner cos it flashes of very quickly . it will be a dirty job cos the cleaner WILL come out between g/box and engine joint.

I WOULD NOT BE PUTTING WD40 IN THERE.

[berniebee]

Before you work on the transmission, you might want to check if the clutch cable or lever is binding. I just replaced a sticky and high effort cable.

[lucian]

If you flush with anything flammable keep a fire extinguisher handy. A spark from the starter gear engaging could end in a disaster.

[pete mcgee]

The clutch hub will be worn and probably the flywheel splines as well.
The fix is replace the hub with the updated version,(roughly double the contact area of the old one and 2 rockwell harder) friction plates to suit new type hub, new intermediate plate because you are in there and the old one will be worn on the outer teeth.
Flywheel teeth, you can knock some of the rough edges and deformation from the teeth but the wont fix a deep groove in the teeth.
Replace the pushrod seals and the oring on the thrust bearing plunger, clean and inspect the thrust beaing,  lube before refitting.
There is unfortunately no quick fix for any of this other than replacement.

Cheers