I'm the second owner of a 93 KDX 200. The top end was done 2 years ago. I've only owned the bike for 3 months. I'm slowly loosing power in the bike (new plug). I was told I need to re-do the top end this off-season which is quickly approaching here in the mountains. In a nutshell, what parts are replaced when re-doing a top end? My clutch needs some work too. I assume the clutch is part of the lower end? Thanks for your help, I've ordered a service manual to help me out as well.
Top End question
- Thread starter riverz
- Start date
I would change your piston and rings. If you're loosing power, more than likely that is the problem. You can get a WISECO piston kit for around $65, and it's a pretty easy fix.
One thing you want to look for when you take the head off and the piston out. Look for any scratches in the piston sleave. If there are any major scratches, I would take it to your local dealer and get it honed out.
Don't forget to change the gaskets. By doing that, you'll notice a big difference. Good luck and Good riding.
One thing you want to look for when you take the head off and the piston out. Look for any scratches in the piston sleave. If there are any major scratches, I would take it to your local dealer and get it honed out.
Don't forget to change the gaskets. By doing that, you'll notice a big difference. Good luck and Good riding.
- Jan 8, 2000
- 3,331
- 1
You'll want to check the free play in the crank as well. There shouldn't be any up/down (non-rotational that is) motion in the crank.
You could be having problems with the powervalve gumming up, which causes the teeth on the valve to strip right off. 89-94 KDX's are notorious for this, particularly the left hand valve. This will hamper power (expecially low-end power) pretty quickly if not fixed. You can check by taking off the pipe and looking up into the ports. On the right side of the cylinder is a plastic cover (3 bolts) and under that is a rod that goes into the cylinder (with another rod attached to that). If you pull on that, you should see BOTH ports beside the main exhuast port open up. If not then the teeth are probably stripped on the valves (aluminum). Good luck.
PS-If the walls are scratched on the cylinder and it is factory plated (IE not sleeved) then make sure you get it replated and NOT honed. Honing will only destroy the plating inside the cylinder. I had this done at Langcourt(.com), they do excellent work for relatively cheap. :thumb:
PPS-If the cylinder checks out and you need a new piston/rings, go with Pro-X piston kit. Its the same as OEM; Wiseco won't last as long because of more piston slap.
PS-If the walls are scratched on the cylinder and it is factory plated (IE not sleeved) then make sure you get it replated and NOT honed. Honing will only destroy the plating inside the cylinder. I had this done at Langcourt(.com), they do excellent work for relatively cheap. :thumb:
PPS-If the cylinder checks out and you need a new piston/rings, go with Pro-X piston kit. Its the same as OEM; Wiseco won't last as long because of more piston slap.
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