Fork Disassembly & Assembly, special tools needed?

I'd like to strip my forks myself & i've never done anything like it before, are any special tools needed for either taking them apart or putting them back together? They are just the standard right way up 36mm's that come on the bike.

a good air ratchet and an allen head socket,a piece of pvc pipe that fits close around fork tube to bang the seals in also helps

Ok Wireman, thanks for that. I have an impact gun & i take it thats for the 8mm allen head bolt at the bottom? Can i use it on the top nut too?

In your opinion is it a job i should attempt myself having never done it before?

im not sure which caps your forks have on top,i usually use a breaker bar to loosen top caps before removing from bike.(make sure to loosen top clamp bolts first though! :laugh: )
if you have a manual and a metric measuring cup while wifes not looking its really simple to do.
personally i prefer to substitute 30w synthetic motor oil for that thin 10w fork oil to compensate for the prehistoric dampening action of stock forks,makes a world of differance in my experiance

Yeah, i heard on my bike if i use 30wt oil & about an inch more than in the manual AND drill the holes on the damping rod out to 1/4 inch it makes a hell of a difference

What is your objective in stripping the forks; are you replacing the seals? Use an impact on the bottom allen bolts, but not on the top. Remove the top nut with a ratchet; just loosen the top clamps first they will come right out. You will need a tool to hold the fork cylinder, probably for removing the bottom bolts and defininitely for properly torquing the bottom bolts when re-installing. Some fork cylinders have an indented hex that the tool engages, others have just a round hole. See which type yours has and make an appropriate tool to hold it. (see below for the round type) Do you have the Kawasaki service manual? If not, do yourself a huge favor and get one before doing this job. They are available on eBay, just be sure to get one for your exact model. While you have the front end stripped down you may want to consider replacing the steering stem bearings with tapered roller bearings. This is a worthwhile improvement. Regarding the fork oil, I HIGHLY recommend you try Bel-Ray 15w fork oil. I've been using it for 34 years and my forks work great. If you decide you would like a softer or firmer ride you can mix Bel-Ray 15w with their 10w or 20w to fine tune the damping. Be sure to use the manual for adjusting the fork oil to the correct level. Ed

KZ650C1 fork cylinders do not have a hex depression, only a round hole as in the picture. To hold this while disassembling the forks you can make a tool by super gluing a 9/16" OUTSIDE diameter vacuum cap to a 3/8" steel rod and putting other end of the rod through a big bolt to make a t-handle to give you a way to hold the rod. I put a clear tube on the rod before gluing on the cap to protect the fork top threads. The friction of the rubber vacuum cap will hold the fork cylinder, but you must apply much force while someone else uses an impact wrench to loosen the fork cylinder bolt.

750steve wrote: Yeah, i heard on my bike if i use 30wt oil & about an inch more than in the manual AND drill the holes on the damping rod out to 1/4 inch it makes a hell of a difference

DON'T DO THAT! You will ruin your fork cylinders! That is one of the absolute dumbest suggestions I've ever heard! Please enlighten us, did it come from a member of this site? :sick:

650ed wrote: DON'T DO THAT! You will ruin your fork cylinders!

Oh bugger.....will it really? Good job i posted then! How does it ruin the cylinders?

Well my seals are good so i might as well just drain the forks & put in heavier oil then!

No it wasn't from this site by the way, im not naming & shaming but it wasnt from here

When you install cartridge valves, I think you have to drill out the dampening rod holes, so maybe that's where the suggestion came from? Definitely don't drill it otherwise.

Ok, i'll leave well alone & just change the oil for heavier stuff, is 30 wt FORK OIL too heavy then?

Saved me some work here for a change! :lol:

750steve wrote: Ok, i'll leave well alone & just change the oil for heavier stuff, is 30 wt FORK OIL too heavy then?

Saved me some work here for a change! :lol:

30 weight fork oil will be way too firm. Here's my suggestion. I would drain the forks and flush them with clean fork oil then fill them to the correct level using Bel Ray 15w fork oil. Ride that and see if it is too firm or soft. Then, if necessary, adjust by replacing some of the 15w with 10w or 20w until you're happy with the damping. I really believe you will be quite satisfied with the Bel Ray 15w. I ride alone or 2 up and the forks never feel mushy. I'm 200lb and my wife is roughly 110 - 115lb.

Do the forks 1 at a time as follows: Open one drain plug and have someone with a catch can help catch the old fluid while you gently pump the front end down and up. This will expell nearly all fluid from that leg. Then, using a bottle jack under the front of the engine with the bike on the center stand, lift the front wheel off the ground and make sure the forks are fully extended. Replace the drain plug in that leg and remove the top bolt (loosen the top clamp 1st to make this easy). Add fork oil until it rises to the correct level. This is measured with the fork spring in place by using a thin wooden dowel or other stick to measure the distance from the top of the fork leg to the top of the oil level. The correct measurement varies from model to model, so you will need to first get this figure from the manual. When one leg is finished, replace the top bolt and repeat the procedure for the other leg. Then take the bike for a good ride. Afterward, check the fluid level again to ensure it has not dropped any. I sincerely believe you will be pleased with the results. Ed

ok, Ed, the 15wt sounds like it'll be fine then. I dont know how available the Bel-Ray stuff is over here as i've been looking their grease for a while now but it seems not to be available in the UK, it must look like C4 or Semtex or something! But if i can get it i'll use it.

I have a manual & can find the oil level ok but doing some of the rest of the stuff you suggest might take a while, especially riding it :lol:





I'm sure i can drain & flush em anyway, i'll top up the fluid when they're back on.

Thank you for your help & advice Ed