Rebuild the stock forks, by Ryan

Please perform a few checks before you start on this rebuild. Put the bike on the centerstand or safely support the front end off the ground, have the bike solidly supported so it cannot move forward and fall over. Firmly grasp both fork legs, pull towards front & push rearwards a few times to check the amount of movement or play. Release all the air from the Schrader valve on the right fork inside the fairing. While the front wheel is still supported off the ground, put a zip-tie on one fork tube, just tight enough to slide but remain in place. Slide the zip-tie down againstthe fork seal. Ease the bike on the ground and gently get on the bike with your full weight, try to have the bike upright as possible, have someone hold it steady if possible. Gently get off the bike and lift the front wheel off the ground again the measure how far the zip-tie has been moved. This measurement is called "spring preload" I call it "sag" here. One inch(25.40mm) of sag is ideal, any amount over 1 1/2" (38.10mm) needs more preload. (no air in forks)
Remove Philips head screw from side/bottom of each fork slider and drain oil.
Remove rubber caps from top of handlebar stay. Loosen pinch bolt on side of handlebar stays and remove Allen-head caps from both forks. Remove inner caps with a 1/2" drive extension, below this cap is the spring so be sure bike is supported. To save space here, I'll just say remove both forks from the bike at this point.
Keep all parts from this point on, separated. Each fork tube & related parts need to remain with that fork assembly. Remove the Allen head bolt at the end of the fork slider, they have Loctite on the treads so be prepared with an air impact gun and a Allen
socket. A 1/2" piece of CPVC plastic water pipe fits inside the valve (picture) this is a special tool if you don't happen to have the real tool. Remove the dust cover seal.
Remove the wire clip, washer and fork oil seals. If you plan on replacing the oil seal and are having a difficult time removing the oil seal, you can hold the fork slider between your shoes and pull up hard on the fork tube to get the oil seal out and tube removed from the slider. Sounds dangerous but it works every time (it may not even damage the oil seals).
Clean up all the parts in mineral spirits (solvent) wash off with water & compressed air dry. Inspect fork tubes for bluing areas, deep scratches, straightness etc. Inspect fork slider bushings. One is located inside the fork slider at the top and has the Teflon material inside it. The other one is located at the bottom of the fork tube and is split. This one usually is the bad one, it's wider then the top one and should have Teflon on the outside edge. If the Teflon on "this" bushing is gone and it's down to the shell, measure the inside of the fork slider tube bore for wear. Sliders can be sleeved but I have no knowledge of this procedure concerning a slider with the anti-dive mechanism. Also I must add Kawasaki no longer has the Teflon bushings, dealers may have some in stock so it's worth calling around. One other option is possibly finding another brand of bike with similar bushings, again I cannot suggest which one.
Inspect to bottom of the fork tube, original Kawasaki tubes are crimped at the bottom. If they have a C-clip inside they are "Forks By Frank" units and will say so somewhere up top. My bike has these "Franks", my best advice at this point is "STOP" Consider locating the original Kawasaki fork tubes or upgrading your bike to a "Hybrid Street Fighter" A short explanation: the C-clip contacts the small tapered aluminum valve centering piece when the forks bottom out. This "eats" away at the aluminum sending small bits of
grit throughout the fork and shortens the life substantially. This is why
Kawasaki crimped theirs. After cleaning and inspecting all the parts, reassembly is next.
First install the bushing onto the bottom of the fork tube, lube it and the inside of the fork slider with fork oil, insert the tube inside the slider. Install the valve orifice pipe on the special tool (1/2" CPVC water pipe) put the aluminum tapered centering part over the end of the pipe and two thin shims, invert the fork assembly and install it inside the fork,
tighten the socket head screw at the bottom of the slider as the assembly rests on the tool. Lube the top of the fork tube and install the upper slider bushing, install the oil seal, washer & C-clip spring and dust seal. The anti-dive needs to be installed before filling the forks with oil. Before installing anti-dive units, make sure both are clean and adjusted
to the same #1 position. With the fork compressed, fill forks with clean 10 weight fork oil about halfway. Hold forks upright from this point on. Slowly compress & extend
fork tube to remove all the air from each fork, this may take a while. Specifications are: 271cc + - 4cc dry. / Level 176mm + - 2mm. / Fork compressed, Spring removed.
After filling forks with the correct oil level, install spring and if the sag was excessive this is the time to adjust that problem. 3/4" (19mm) thick CPVC water piping works well for this also, it's light and non-damaging if bits break off, steel washers also work well, keep your shim light as possible, example: Solid brass= Heavy.