Thread: Can I bore out a 1999 Kawasaki kx80 dirt bike to fit a 55mm piston?

I already bought the piston on eBay and I don't think it will work, I used all the money I had

According to Wiseco you can only go to 50mm.

http://www.wiseco.com/Catalogs/DirtBike.aspx

To go bigger you need a Big Bore Kit.

http://www.lukesracing.com/luksr/kx80.html

May not last too long, as you will have eaten too much into the bore, which will cause over heating problems etc. Also you would probably need to do some serious skirt work on the piston to ensure correct mixture flow or adjust porting. Can't see all the work could be worth the gain. If you need so much extra from a motor as small as an 85, perhaps you need to go up a class.

May not last too long, as you will have eaten too much into the bore, which will cause over heating problems etc. Also you would probably need to do some serious skirt work on the piston to ensure correct mixture flow or adjust porting. Can't see all the work could be worth the gain. If you need so much extra from a motor as small as an 85, perhaps you need to go up a class.

May not last too long, as you will have eaten too much into the bore, which will cause over heating problems etc. Also you would probably need to do some serious skirt work on the piston to ensure correct mixture flow or adjust porting. Can't see all the work could be worth the gain. If you need so much extra from a motor as small as an 85, perhaps you need to go up a class.

According to Wiseco you can only go to 50mm.

http://www.wiseco.com/Catalogs/DirtBike.aspx

To go bigger you need a Big Bore Kit.

http://www.lukesracing.com/luksr/kx80.html

May not last too long, as you will have eaten too much into the bore, which will cause over heating problems etc. Also you would probably need to do some serious skirt work on the piston to ensure correct mixture flow or adjust porting. Can't see all the work could be worth the gain. If you need so much extra from a motor as small as an 85, perhaps you need to go up a class.