Fork oil change- can't get the top nut off

'71 Commando. Want to replace fork oil without taking the forks off and apart. Unscrewed the fork top nut but it won't come off. How do you do it? I thought of pushing it in from the bottom with a syringe, but that can be messy/ inaccurate. Does the wheel have to come off and unscrew the bolt coming up from the bottom?
Thanks
Doug

Douglass Harroun said:

'71 Commando. Want to replace fork oil without taking the forks off and apart. Unscrewed the fork top nut but it won't come off. How do you do it?

Click to expand...

Support/jack up the front end so the weight is taken off the forks.

Once both fork top cap bolts have been fully slackened, simply compress the forks a little (by lifting and chocking the front wheel so it sits a few inches off the floor or by lowering front end slightly) and the cap bolts will have risen far enough out of the forks so fresh oil can be added.

Yes lke L.A.B. says. Once the fork caps unscrew from the yokes they are still screwed to the damper rod so don't come up unless fork compressed some or you reach in under them with a spanner to stop damper tube just spinning with the caps. Once cap lifted enough 1.5" or so to expose springs/damper tube I use a cattle syringe to fairly slowly squirt a measured amount in, usually 175 ml, so just short of hydro lock up after 1/4 mile too small air bubble pumps out.

Yes lke L.A.B. says. Once the fork caps unscrew from the yokes they are still screwed to the damper rod so don't come up unless fork compressed some or you reach in under them with a spanner to stop damper tube just spinning with the caps. Once cap lifted enough 1.5" or so to expose springs/damper tube I use a cattle syringe to fairly slowly squirt a measured amount in, usually 175 ml, so just short of hydro lock up after 1/4 mile too small air bubble pumps out. Oh yeah if ya lift springs out too far ya can't get all the lube in before over flows.

How to change the fork oil is covered in section K11 of the factory manual: http://britmoto.com/manuals/Manuals/750_man.pdf

Measure the amount 150cc into a pan and warm it on the stove untill its hot ,this thins it ,and pours in easy, 20's out of the bottle will take some time and flows over causing much swearing :lol: have plenty of rag handy and close the garage door,,,you dont want the kids hearing you !