What i do ? Piston rings and letters ... 2011 kx450f

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8/7/2018 6:41 PM
Edited Date/Time: 8/7/2018 6:42 PM

Hey Guys !
I opened the engine of my 2011 kx450 to change the head gasket and the mechanic said it would be good to change the piston rings. But I could not know the brand of the piston. In the Wiseco catalog there is only the 4980M09600 numbering, except that the piston that is on my motorcycle is numbered 4980N9600, and I am in doubt as to whether it is wiseco or not. I thought of changing the full piston, but I should not look for another piston 96.00 forged or if I can put a 95.97 or 95.98 without being forged, for dilating more than the forged .. can anyone help me? Thank you guys


8/7/2018 6:49 PM


8/7/2018 8:56 PM
Edited Date/Time: 8/7/2018 9:03 PM

How many hours are on the piston? If there’s a descent amount it’s good practice to change the piston as long as the bore measures good... also almost all modern 4 strokes use forged pistons


8/8/2018 2:57 AM
Edited Date/Time: 8/8/2018 3:04 AM

Buddy id just change the piston all together. Or call wiseco and see if that N variant is a different diameter. Ive got a wiseco sitting in my garage for my 09. Ill see what it says. Its a high comp piston so its prob different tho


8/10/2018 1:10 PM

I'm seeing MO9600 in the piston picture. What am I missing?


8/11/2018 12:17 PM

What's up guys? I decided to change the full piston with rings, to avoid future problems they told me about the skirt. Here in Brazil the pistons are sold by letters a, b, c ... I looked for a lot, but I was in doubt. Do you take these letters into account when changing pistons? because even in the site motosport.com does not have these letters.

8/11/2018 4:04 PM
Edited Date/Time: 8/11/2018 6:48 PM

The letter variation is all about how much piston to cylinder wall clearance you have/ want.. cylinders are often stamped with their coresponding piston letter at the factory... most aftermarket pistons are based off the B piston spec I believe... in a used bore you will probably end up with a C or a D in order to achieve the recommended clearance... look at your manual find the service limit tolerance and measure your bore to make sure your cylinder is within the spec... if it is, find out how much piston to wall clearance your manual or piston company wants, and go based off that( most modern 4 stroke are around .0018-.0025 of clearance)... each letter increment if I remember is roughly .0004 of an inch... to find piston to wall clearance take your measured bore size and subtract the piston size... the current piston you have in there is based off the B spec...