IT 250 1978 kyb forks.. how to improve?

[ghostdancing]

hello gentelmen, i'm from italy and built last winter an XT250g twinshock modified to look like a small HL500; front fork comes from an IT250 1978, it's a KYB 36mm.. i just had new seals installed and fresh ATF oil in.. but its' harsh and uncomrfotable.. i use the bike on pavement and light offroad only (bike it's license plated and got minimalist lights also)..

how can improve the fork behaviour?

p.s. would like to insert a shot but wasnt able to make it..

[Tomas]

You can experiment with various size holes in damper rods or instal fork emulators from your prefered manufacturer. Emulators also called gold valves are adjustable valves that fit inside fork tubes and allow you to fine tune your suspension to certain extend. Can also experiment with fork springs. Heavier or lighter spring will make your forks stiffer or softer  Also it is beter to use shock oil rather than ATF since you can buy shock oil of various weights.5w, 10w etc.

[ghostdancing]

hi tomas, tnx for your help;

i know that ATF is not loved by many guys out there.. it should be around 7\10W and it's ready available and cheap, that's why i used it.. forks oils are insane expensive here.. anyway will try it in this rebuild.

emulators: i only know the race tech gold valve: are there other manifacturer that make them?

also: i never changed the bushes: how to carry out this job?

[80-85 husky]

atf should be ok for those forks. how is the level? if the volume is too high, the forks will be harsh. do they have air caps?  air can make the forks harsh as well.are they harsh on little bumps? or harsh on big hits? are they bouncing back in your face? cheers

[ghostdancing]

hi husky, dont remember the fluid quantity right now.. but i asked in the yamaha IT forum last winter and filled accordingly to their suggestion..the top caps havent air valves (it's a rather primitive version of the kyb 36..) i feel it harsh on small bumps, probably it goes well on bigger hits.. but dont ride agressive this bike and would like a smoother action at lower speeds..

regarding the ATF.. i just used it in my rear shocks (chinese cheap JBS, they comes low in oil from the factory, but are rather well made for what i saw inside) it is working well anyway

[GMC]

The forks shouldn't be overly bad in stock trim, how much preload do you have on the springs?

[ghostdancing]

hi goeff, the preload it's fixed.. i mean that there is no spacer between top cap and spring.. the top caps are longer then usual (sort of built-in preload spacer.. if you know what i mean)..

on the IT forum, they told me that ATF it's too thin.. they suggest 250 cc of 20W oil...but bike is light and i'm not a big guy..20W seems to me too thick..

BTW how to upload a pic? must host the photo on an hosting website or can do directly from my pc?

[80-85 husky]

you need to use a photo hosting site and link posted here. did the sliders move over the legs ok? there are no minor bends in the legs?

if 20wt oil is specified (seems heavy to me too) it may be worth a try at some stage if there isn't a mechanical issue.

you haven't pinched the forks in to the front wheel by accident? this can cause harsh action. check the forks are parallel at the seal head and the bottom (same distance apart).

damper rods centred in tubes ok, moved freely? Husky forks have two traps for newbies, I don't think kyb's have the same issues. husky damper rods must be tightened with the fork tube fully bottomed in the slider to centre the damper rod. also the axle mount floats and it is easy to pull the forks into each other if you don't take care when putting the wheel back in.

I don't think these issues could be your problem but worth running the tape over it

[ghostdancing]

husky, the forks are in nice shape indeed.. no bends and no accidents.. i would like to check and probably change the bushes.. actually it's a job that i never did in 25 years of motorcycle thinkering (dont love so much to work on forks)..do i need special tools to carry out this job?

tnx guy for your help from downunder

for those interested to have a look here the old lady:

http://www.yamahait.com.au/forum/index.php/topic,21804.0.html

(i'm not so good with hosting images..)