Primary drive nut

Could someone please tell me how to hold the crank when trying to tighten the primary drive nut on an exc 250f.

I have tried the penny between the clutch and the crank and just mash the coins.

I was told by my local ktm dealer to use the bolt in the front of the crank case but that just bent (nother issue).

Have read in many post about this issue but never on how to hold whilst tightening.

Many thanks in advance. John

I havent done a 4st yet myself, but IVe used the penny and put the bike in top gear andf held the brake at the same time on a 2st to get it done.

I removed the primary nut with an impact wrench, cleaned the threads with contact cleaner and covered the same in medium thread locker. I set the air pressure at 100 psi and gave it 4 big whacks holding the clutch with a leather glove. Perfect for trail riding. The factory didn't have 50 psi on it when I removed the nut.

If you can't sleep with 4 big whacks, KTM will take your money for a zoot capri looking metal comb. With that you can surgically apply the most expensive Chinese torque wrench available and cinch it properly.

I removed the primary nut with an impact wrench, cleaned the threads with contact cleaner and covered the same in medium thread locker. I set the air pressure at 100 psi and gave it 4 big whacks holding the clutch with a leather glove. Perfect for trail riding. The factory didn't have 50 psi on it when I removed the nut.

If you can't sleep with 4 big whacks, KTM will take your money for a zoot capri looking metal comb. With that you can surgically apply the most expensive Chinese torque wrench available and cinch it properly.

:lol: exactly- chinese torque wrenchs- funny how people break more bolts with a big a^$ torque wrench these days huh... supposed to use something like 8 lbs and the T-wrench is long enough to be a good breaker bar.

I have used the penny trick- and yea- you can go through a couple pennies- but they are cheap- Main THing: keep track of that penny- if it starts to sheer- start over: and don't loose it in the motor. I have found that 2 work pretty good- you can still sheer them though- its alll about finding the right placement- and no I can't explain that.

you can incorporate the gear's and rear tire too- find what works for you - do the job right and you won't mess with it again (probably)

Have now completed the job, using the penny method.

But have also ordered a motion pro clutch holdering tool (as shown in the haynes manual) which can hold the clutch and or the crank. Only cost £20.00. Many thanks to all have replied with help. Regards John

Great post,

 

I´been having problems torquing de primary drive nut of my 450 xc-w, the shop manual says 73,8 lbs./ft., anyone can send a picture of where do you put the penny?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now