Come on guy, you really are putting us on - right? You say you are "heavy" at 140 pounds! So an average weight rider is what - maybe 85 pounds? Did you notice the seat on the bike is built to carry 2 people? So if 140 pounds is heavy then carrying 2 folks who each weighed 70 pounds would be stressing the stock front forks? The bottom line is that Kawasaki was not building bikes for little children who were feather weights, so the stock forks are far more than enough to carry anyone weighing 140 pounds. In fact, the front forks can very easily carry 2 folks who weigh that much with no problems at all. The rear shocks are a different story; the stock shocks were only ok when new and they quickly worsened to a point where they were awful.
The bigger question is how do you plan to use the bike? If you plan to use it on the street the stock forks in good condition work perfectly fine. I know because I've owned my KZ650 for more than 42 years (62,000 miles) and the stock forks still work fine even though I now weigh 200 pounds - of course I do change the fork oil on a regular schedule. If you plan to seriously race the bike on the track you may want to invest in some very expensive suspension parts, but that still won't make a 42 year old bike competitive with many of the newer machines. However, if you install racing suspension pieces on the bike and use the bike on the street you may quickly learn that public roads with bumps, potholes, etc. have totally different qualities than race tracks that are meticulously maintained and that racing suspensions may not work particularly well on many public streets . Ed
650ed wrote: Come on guy, you really are putting us on - right? You say you are "heavy" at 140 pounds! d
It was a typo for 240 lbs. I installed race-tech emulators and springs on my 750 twin. It completely transformed the front end. Brake dive is gone, road holding is improved. the bike handles incredibly well for its age. Well worth the expense IMHO.