Possible Kz400 big bore pistons.

Playing around with my Kz440 and had to remove the piston because of a stuck piston ring. So I decided to go through an old Wiseco catalog I have checking the pin sizes to see if any would come close to the 440, and well turns out nothing for the 440 but the Honda ATC200S has the same pin diameter and compression height as the kz440 piston I have, which translates to it has the same compression height as the 400 engine while having a larger bore. The ATC200S is 65mm standard bore and is available all the way out to 67mm with a domed piston that in the Honda would be 12.5to1, but I don't know what it would be if used in the KZ400. They also have a smaller dome that is 10.25to1 while the standard piston design is a dish, which would be ok for use with a turbo.

I'll get a picture of the 200S piston I have as compared to the 440 piston. I only have an old Sudco dished piston part# 624-031 on the box.
Just something to keep in mind as it may save one of these old bikes from the scrap heap.

Do you know the combustion chamber volume of the Honda?


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No I don't. I used to have a head but I no longer have it, or else I could have CC'd it. The only major thing that would have to be done to use the piston is between the pin bosses needs to be opened up a little, it is totally doable at least on the Sudco Piston.

13bravo wrote: No I don't. I used to have a head but I no longer have it, or else I could have CC'd it. The only major thing that would have to be done to use the piston is between the pin bosses needs to be opened up a little, it is totally doable at least on the Sudco Piston.

Dome shape and height could make it a no go.


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Finally got the camera charged to take some pictures.

Here are the Wiseco pistons.
www.wiseco.com/ProductSearch.aspx
I've been trying to find a picture of the dome.
The only image I could find is from ebay.

That dished piston is taller than the domed piston.
Vertical clearance might be an issue with that cast
dished piston for the small end of the con rod.


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No stock piston to compare with?
Steve

No eBay APP ID and/or Cert ID defined in Kunena configurationThis is available on eBay. There other options as well.
Steve

No eBay APP ID and/or Cert ID defined in Kunena configuration

swest wrote: This is available on eBay. There other options as well.
Steve

Try finding rings.


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swest wrote: No stock piston to compare with?
Steve

The stock KZ400 piston actually has a taller dome than the KZ440.


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There's rings listed too. The thing I don't understand is the different type of pistons.
Steve