well its just that when i push the bike along and grab the brake theres a slight judder that i think is play in the bearings ,how do you tighten them up? yes bikes standard just mean a carb balance , not sure re the valve clearances i know its been done in the past ! bikes only done 20,000 ms
Have you checked the disc bobbins are free? It may be they are seized.. Could also be warped discs or seized pistons in the caliper.
To check the head bearing play you need to put the bike on a front wheel lift and turn the bars from full left to full right. You can feel the bearings if they grind or hinder the free movement of the steering. Also when the front wheel is off the ground, grab the rim and push and pull front to back to see if theres any play in the steering head.
Might be worth looking into a chip before having the tb's balanced and co set.
Bobbins are the POLO sized rings which hold the brake discs onto the carriers. Grab hold of your discs & see if they move back & forth, if they do this gives the same feeling as knackered head bearings. If your discs have more than about half a mm of movement your discs are shagged.
You can't tighten the ball & race headstock bearings, in reality after 20K they are proberbly notchy & worn, it's easy to replace them with taper bearings which can be tightened if they become slack.
As far as I know they adjust fueling quite dramatically they are very sensitive. 12 o clock is a good base setting. Would ecomment co and tb setup by griff or someone similar to get the most out of it