KDXRIDER.NET

Hello everyone. I'm writing for your wisdom on installing an aftermarket piston. I want to be sure I order the correct parts and all, while I have the cylinder on the bench.

TL;DR... is a Wossner 8092 the right one? The Wiseco 750M06900 (Kawasaki KDX220 '98-05 ProLite 2717CD) seems to be out of stock.

The plating on the cylinder looks and feels good. I've read that I should scotchbrite it before introducing a new piston. ... using one of the familiar, rectangular, green Scotchbrite pads??

I plan to order a stock-sized piston, i.e. 69mm. The one that came out of my bike had an "A" on it, and that corresponds with the "A" stamped on the cylinder.

I'll purchase a new top end bearing and gaskets. The rings and wrist pin should come with the piston.
Am I overlooking something, perhaps?

I used my vernier caliper to measure 3 different points of the diameter of the piston and cylinder, and this is what I came up with:
Top of cyl: 68.6-68.9mm
Bottom of cyl: 68.6-68.9mm
(near the) Top of Piston: 68.7-68-8mm
(near the) Bottom of piston: 68.8-68.9mm
- Should I be concerned that my measurements are less than 69mm?

Looks good on shopping

there are a few ways to properly measure the ID of a cylinder. A bore gauge is one, but calipers is not.

Yeah, you're not going to get very accurate results with calipers. Are you just replacing the piston? Or are you tearing the jug down and cleaning the KIPS while it's all apart as well? If so, don't forget the 2 oil seals on either end of the KIPS rod, they don't come in a top end gasket kit.

Right-O! Cylinder measurements in English units need to go to four decimal places (e.g., 0.0001 inch). The reported measurements in tenths ain't good enough.

Yes, Wossner number 8092DA is the correct stock dimension piston. However, a worn cylinder is not likely stock dimensions in both roundness and diameter. It's important to make many measurements to three four decimal places to be sure if it is possible to remain with stock piston dimensions.

It's worthwhile to replace the top end bearing while in there. Bearing dimensions are 16 x 21 x 19.5 mm and costs about $20. Also get a top end gasket kit. My most recent package of these gaskets was manufactured by Namura.

Use very sharp & very fine files when fitting piston rings to the cylinder.

It's also worthwhile to clean the power valves really well. They get gunky. You'll be happy if you make many really good photos while taking these mechanical assemblies apart.