OzVMX Forum

Marque Remarks => KTM => Topic started by: ozktm on April 20, 2010, 10:36:37 am

Title: 81 250 Clutch slip
Post by: ozktm on April 20, 2010, 10:36:37 am

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 :
(http://api.ning.com/files/97535Lff9AXuXiUuBzBOXv8sXVBxP8zuz6s6hu5V6ROmaEPw3LReUtcWpV4FXHqlV7R5UwpUY*xyJ-1krTt41EDHQMWchOxC/P4200366.JPG?width=737&height=552)

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

Title: Re: 81 250 Clutch slip
Post by: Slakewell on April 20, 2010, 10:47:06 am

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.

Title: Re: 81 250 Clutch slip
Post by: ozktm on April 20, 2010, 11:09:45 am

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. :
(http://api.ning.com/files/97535Lff9AWcAB37JZjAv1HTVNXXZ7VT9RoVj971BNNhJbaOd4xNlyykuADkZD-umnYiGdiQiD42o69BXEHGM2y6RETmTpYb/P4200369.JPG?width=737&height=552)
(http://api.ning.com/files/qKGVCA0vGSDICxdVdwgO6wCPRlrzcCcZPq3i5reGeqFSxM3bERux5gz2VMViTUJhznQhCECZc7hBUHNMgGoLd8JaI6z-jelR/P4200370.JPG?width=737&height=552)
Same part numbers, must have made a change later.
(http://api.ning.com/files/dlLdygyl3XbmWcOgvCUCORt9nOn3RUz8rBO2IVBOwEE5dFV6bZa4bEk1FDNq*ujzyWt703f2fKjpfhomWr0LWZOlQaS7DnJ9/P4200372.JPG?width=737&height=552)

Title: Re: 81 250 Clutch slip
Post by: Tossa on April 20, 2010, 01:56:08 pm

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

Title: Re: 81 250 Clutch slip
Post by: ozktm on April 20, 2010, 09:31:13 pm

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

Title: Re: 81 250 Clutch slip
Post by: ba-02-xr on April 21, 2010, 08:16:15 am

That just looks nasty :o.

Title: Re: 81 250 Clutch slip
Post by: Mike52 on June 07, 2010, 08:07:13 pm

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.

Title: Re: 81 250 Clutch slip
Post by: ozktm on June 07, 2010, 08:58:34 pm

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