Use 5wt. fork oil or ATF Dextron II/III. I've use both and have the 5wt. fork oil in now. Suppose to have a lighter pull but can't really tell any difference. Use a large syringe to pump the oil in from the bleeder at the bottom up to the master cylinder.
I had the same problem after a 2 hour enduro section, a quick change to the same 10W light gearbox oil and a not too tight lever adjustment did the trick. leave a little play before the lever hits the nissin plunger, when you get a bit of heat into the oil the play gets taken up.
×