OEM piston by color?

[psalm3124]

I have an 06 yz250. When I went to the Yamaha microfiche to order a new piston I see it's labeled by colors (red, orange, green, purple). This will be my first piston change on the bike. Does anyone know what color I need to order? or do I need to remove the current piston and take a look? (I was hoping to order the piston then change it all in one afternoon so I wouldn't miss a day of riding while I wait for shipping etc). Also, I can't seem to find a way to order the necessary gasket kit on the microfiche...

here's the site I'm using...

[UpAllNight]

On the cylinder will be a letter (A,B,C, or a D) facing the carb, just over the reeds. This letter is in ink and does fade away through time... hopefully yours is still there.

In the manual it will tell you which color goes with which letter.

If yours has faded and cant be read then just buy the one for a B cylinder, since every 06 I have seen so far has had a B cylinder I would put my money on it that yours is too. And ifs its not a B, who cares since the size differance is so little anyway it really doesnt matter.

[Bambislayer]

i will always run a d piston in anything but a new cylinder. the difference is not worth worrying about.

[JimXCW]

I have a B cylinder on my 06 but decided to order a Wiseco Pro-Lite piston kit. Wiseco sells one piston for these bikes regardless of cylinder letter / color. The difference between A, B, C, & D cylinders is so small that I can't see it making much difference.

The guy I ordered from told me the Wiseco pistons are lighter and expand more so no need for different sizes... I don't know I just hope it lasts!

[psalm3124]

I used wiseco in my 02. Seemed to work fine. With my 06, I want to go with OEM for now.

Thanks all for the input:ride:

[Markopolo400]

I will never buy another OEM piston, or Vertex, or Pro-X for that matter.

Wiseco pistons have lasted much longer in my bikes than anything else. That's all I'll run.

[mxjosh]

Funny, I will never buy a Wiseco again.

[JimXCW]

Why won't you buy Wiseco? bad experience or something...