1990 Kawasaki KDX 200, Classic Motor Cross, Renovation Tips.
Two Stroke Rocket
Hitting the market in 1983 and last released in 2006 The Kawasaki KDX is a true competition Motor cross Bike in the same market as the Suzuki RM, Honda CR and Yamaha IT series. The Original Models were air cooled but became water cooled from 1988 onwards . The KIPS (Kawasaki Integrated Power Valve System) was introduced a year later and remained until the last release model. The KDX was light, powerful and built a reputation as being hard wearing and very reliable.
My Kawasaki KDX 200 is a 1990 model with telescopic front forks . Single Rear Mono Shock . Electronic CDI ignition. KIPS power valve on exhaust and reed valve intake. Bike develops 37hp at 8000 revs delivered through a wet multi plate clutch and a six speed gearbox. I purchased the bike quite cheaply knowing that It needed some work.
Common Issues when you buy a second hand KDX:
Firstly I re-built the front forks internally and also replaced the fork seals. I then replaced the steering head bearings, threw in new disk pads front and back and bled the brake system replacing the brake fluid. Keeping in mind this bike is nearly 20 years old I changed the gearbox oil and then ran the bike looking at the glass window to see if the oil had changed color. If the oil turns a milky brown color this is a sign that the water pump seal is worn. Sure enough the oil showed signs of leakage so I had the oil pump rebuilt and seals replaced. This is a common problem with water cooled bikes of this age and should be one of the first things to check. I then had the KIPS power valve system rebuilt. Again if you are buying a bike this old the power valves are most likely not working. The bike will run without the power valves, and unless you are familiar with a KDX 200 you won't know what to listen for or what power you are missing. Typically the power valves give you a much broader power delivery particularly at lower revs. The bike will also chew through fuel . Once rebuilt the power valves give a noticeable improvement to the bikes performance. My bike also has an aftermarket Pro Circuit exhaust pipe which improves horsepower over the original unit. Finally I replaced the front and back tyres and was ready for action.
Once setup right the KDX 200 is a real rocket ship with awesome acceleration and grunt. It has good ground clearance and the long suspension travel soak up the bumps. This bike is designed to be ridden hard and fast, if you toodle around you will eventually foul up plugs and fill the sump with two stroke oil. Like the Honda CR and the Suzuki RM these bikes are competition Motor Cross Bikes and give you a level of performance to match. The Tracks I ride on are often steep and rough but the KDX just fly's upwards digging its way through the boggy stuff as fast as you can hang on. They still keep up with modern bikes and have a history for reliability. Like other high performance two strokes they are noisy, dirty and oily and don't suit everybody but for me they are a real adrenalin rush.
Parts for these bikes are getting harder to come buy and you may have to do a bit of ringing around. Having said that I have found all the parts I have needed so far. The CDI units are very expensive new but can be found second hand for a reasonable price. Remember to be very careful when working on the electrics on any bike with CDI as you can easily blow the unit up. If you are going to test circuits or solder wires make sure you unplug the CDI unit first.