Thread: Change the Cylinders of My Honda 125 Motocross

Hi,
I wish change the cylinder of my Honda 125 motocross with a increased displacement one, if exist it.
I know that Athena products it for Yamaha, with 150cc displacement but don't products for Honda 125 (while it products for CRF 250...).
Do you know who products it?
Are they very reliable?
How much cost they? How originals?
Thank you

Lemme translate. You're asking who makes larger piston heads for a Honda 125cc? You can usually bore the cyliders out and put pistons in from several companies. JE are one of the better ones. Weisco etc. Just google "Motorcycle Pistons" and you should get some hits. You'll need to know the cylinder bore and what you are boring to. They may be able to assist you over the phone or by email if you supply the bikes info though.

My friend had this Yamaha DT 125cc enduro bike with some "tuning" parts between the cylinder and carburetor. Then he changed a 180cc cylinder and bigger carburetor to his bike but this "tuning" part didn't fit there anymore (I don't know how to translate this part) . Outcome = much less torque, somewhat increased top speed, throttle response was really bad etc...He switched back to 125cc pretty quickly.