fork damper pistons

I read In Jim Schmidt's note about re-sizing the damper piston to get it to withn 5 thou of the bore. I have done all th rudimentary upgrades such as the Covenant upgrade shifitn gholes and putting in extra spaces. I have progressive springs tat make the bike suspension a little softer in inital movement. But I get chronic top out and bottoming out on apoaching drive way gutters etc. So has anyone experience of re-sizing the damper piston? I can spin up some new ones if necessary! I think my forks are a little under damped right now, I have 20wt oil 150cc. The inherent stiffness of te fork action, gives some sort of dampening, but there seems to bevery little hydraulic dampening going on. Any idea's? I know the Landsdowne is probably the ducks guts, but I would like to have a crack at getting the original stuff work first.

Cheers Richard

P.S. I did some searches, but come up nought, but happy to be re-directed to previous info.

I have just spun up sets of Amco 15 cap bushings for the top of the Dampener tubes. Contact me via email if you like. The I.D. A bit tighter than stock. Details to follow.

I would go to 30wt to improve the bump stop characteristic first.
If you are still topping out badly but do not have a problem bottoming I would back off some preload - unfortunately my experience with progressive springs is that they are too soft in the initial rate and you may get too much static sag.

You can use a suzuki Teflon impregnated bushing on the bottom as in the race manual. But the next big improvement is a Turkite upper bushing to reduce stiction.

Unfortunately - you have to make them yourself.

I'm so very happy with Greg's kit and spring spacer with power steering fluid.
You can cut up various spring lengths and brew your own mutli rate progressiveness.
Do know cutting springs stiffens them.
Peels' forks have worn top and bottom bushes so almost disappear vibrating when sliding front sideways over choppy surface, but I can't feel or detect a thing on loading them till they flat leave the surface. I'll be ordering any and everything Greg and Jim offer for any refinements possible, mostly for fun and visual help.
Will test the other offerings someday to find the pecking order in Roadholder mods. At this point comparing with sports bikes, don't want non of that corner cripple and off road intolerant gear on Ms Peel. Not on my Life or vibration sensitive wrists.