Rear Axle Torque

[ZacharyB]

Hi everyone,

I'm curious about the rear axle torque for the 250. The service manual lists it as 80 ft-lbs. I also own a GN125, but this motorcycle has an axle torque range instead of a specified torque: "36-58 ft-lbs."

The reason I'm wondering about the rear axle torque is because the threads on my axle are starting to look flat, like when a bolt is over torqued. I am not sure the rear wheel has ever been off before I got to it; it had the stock tires on it, from 2004. Could the 250 have an "engineering range" of torque that they just don't publish? Judging by the wear on the axle threads, 80 ft-lbs. seems kind of high.

[Motofool]

Originally Posted by ZacharyB

.......... Could the 250 have an "engineering range" of torque that they just don't publish? Judging by the wear on the axle threads, 80 ft-lbs. seems kind of high.

The thread in the Suzuki GN 125 is M12, while the thread in the Ninja 250 is M16.

Please, see the values in the following chart:

http://www.dansmc.com/torque_chart.htm

The range given for Suzuki applies for the low grade steel and grade 8.8, while Kawasaki specifies the torque for low grade steel.

A healthy thread of the axle and the nut of the Ninja can stand higher torque than the specified, no problem.

If the interior diameter of the castle nut is 14.5 mm, the nut will fail before the thread of the axle does.
It seems that the axle has not been out as many times as for having the thread damaged.
It is a fine pitch (1.5 mm), so the cut is not too deep.

Applying less torque than specified by Kawasaki will create several problems:
1) Bent axle.
2) Wheel's misalignment.
3) Misaligned sprocket.

Keep the bike from falling over when you apply the torque and push forward, so the tensioners are loaded rather than the chain.

Please, see:
http://faq.ninja250.org/wiki/How_do_...chain_slack%3F

http://forums.ninja250.org/viewtopic.php?p=853294