81 250 Clutch slip

[ozktm]

When i got home from Buladelah, i drain the gearbox oil to then work on the clutch and find out why i had clutch slippage in the last two races.
Oil came out looking like liquid Aluminium!! Then removed cover to find this :


multiple broken plates etc etc...... Looks like i am going back to the sintered steel plates.

[Slakewell]

One of the better KTM clutch tricks is to replicate in steel the plastic bit the arm that connects to the cable is housed in.
If you watch it when you pull the clutch in and out you see how much it flexes as it gets older. I have made a few of these for the Lewis boys.
Really helps with clutch drag on the start line. Also a genuine Yamaha XT 550 lever and perch, it needs to be this model.

[ozktm]

i have a rare original aluminum one fitted to mine. Haven't seen any others, came on a set of cases i got from the states.
Also found that there is two different types of pressure plates, didn't take much notice before. :


Same part numbers, must have made a change later.

[Tossa]

what brand of clutch plate did you use Adrian.  Does not look nice.

I'll also have a look at my clutch arm, when i get the motor back as well, Slakie

It's terrible to think out of someone else's adversity you learn so much.  But then again you guys have been a great help so far with my build.  Slowly but surely.  I'm giving another week before I press the clamps of the 1980 and replace the 81 triple clamp if i can't find one.

Barry

[ozktm]

Barry,

they were original ktm aluminium plates. But there were also available a steel ones with sintered brass, i will be using these as i have a set.

Adrian

[ba-02-xr]

That just looks nasty .

[Mike52]

Don,t know if this is relevant but the guys from Woolgoolga told me ( in 1982) to put ATF in the gearbox to stop a dragging clutch.
Tried it. Works well. Gotta change it EVERY race tho.

[ozktm]

KTM workshop manual states to use ATF as standard.
Sintered steel plates and steels have been swapped in and working.