XR200 piston in ATC200ES?

[GTO]

Here in South Africa pirate parts for the ATC200ES aren't available, getting XR200 parts aren't a problem.
I used valves, gasket set etc before, but would an XR200 piston work in a ATC200ES engine?
I realize compression would be higher, would the jetting have to be changed?

[oldskool83]

yes pick your bore size and go play

[shortline10]

Jetting shouldn’t be much different but you could bump it up to a 108 just to be sure it’s not running to lean on the main jet .
As for the piston , std size is half mill larger on the xr piston so an over bore will be needed if your still at std bore on the Atc .

Just make sure your not buying a xr200 4 valve piston, that’s definitely different .





Here in South Africa pirate parts for the ATC200ES aren't available, getting XR200 parts aren't a problem.
I used valves, gasket set etc before, but would an XR200 piston work in a ATC200ES engine?
I realize compression would be higher, would the jetting have to be changed?

[GTO]

Jetting shouldn’t be much different but you could bump it up to a 108 just to be sure it’s not running to lean on the main jet .
As for the piston , std size is half mill larger on the xr piston so an over bore will be needed if your still at std bore on the Atc .

Just make sure your not buying a xr200 4 valve piston, that’s definitely different .

Thank you, I wasn't aware there was a size difference between the XR and the ATC200.

[tripledog]

The (United States market) 1984 and 1985 Honda XR200 RFVC engines had 2 intake and 2 exhaust valves, and are not compatible with the single intake and single exhaust valve engine design of the 200ES.

[BarnBoy]

Yes, as along as you get the 2 valve piston itll work perfectly. Anything 81-83 and 85-up i believe. Compression ration is 10-1, vs stock 200es 7.8-1. Cam with fit too and give you a nice bump.