MotoPartsmax.com has a large online selection of 125cc Motocross bike parts, which includes a separate section for 125cc manual clutch engine parts. The Powersports Max website is another comprehensive online source for 125cc bike parts.
Motopartsmax.com has 286 parts for 125cc Motocross bikes plus 62 engine parts specifically for 125cc bikes with a manual clutch. Ordering from the site can be done online or via a toll-free phone number. Motopartsmax.com also has ATV, go kart and moped parts with an emphasis on Chinese-made models.
Powersports Max offers 91 parts for 125cc bikes, and the site also offers online and telephone ordering options. Its stated shipping time is 48 hours from the time of order, and it provides a phone number and map for its showroom in South El Monte, California for any items that might need to be picked up in person.