hi just took apart a bike I bought for my son to put a new piston/rings in it. besides the cylinder damage that we found we also see the piston used is not a kx100 size (50mm vs 52.5mm). it is closer to an 85 in dia. my question is - the vin on the engine is kx100ce009503 which leads me to believe that it is a kx100 yet the piston is way off - is this a correct way to identify the engine?? the frame is a factory frame that is an 85 but the guy that sold us this told us the engine was a 100. if this is a kx100 engine could they have just put an 85 cylinder on it?? can i just get a kx100 cylinder and it will work correctly? - really got screwed on this used bike!!!! please help.
KX 100 or so I thought
- Thread starter cc13lab
- Start date
Canadian Dave
Super Power AssClown
- Apr 28, 1999
- 1,202
- 0
Yes you can just install a 100 top end, including the cylinder, piston and head.
The kx 85 and 100 top ends are interchangeable so its quite possible that someone has installed an 85 top end on your 100.
You've got a couple options from here. Given that the cylinder is damaged and will need to be replated I would give Eric Gorr at Forward Motion Racing a call and do one of two things. You could have your head enlarged (assuming its not a 100 head on a 85 cylinder) and the cylinder bored to 100cc specs and replated, Your second option would be to purchase one already done. Check out Eric's garage sale items. He typically has 100cc cylinders ready to go. There are others that can do the same job but I haven't seen anyone with more reasonable prices or better service.
Complete KX100 top ends are typically in the $400 range form Eric and come ported to suit your preference.
The kx 85 and 100 top ends are interchangeable so its quite possible that someone has installed an 85 top end on your 100.
You've got a couple options from here. Given that the cylinder is damaged and will need to be replated I would give Eric Gorr at Forward Motion Racing a call and do one of two things. You could have your head enlarged (assuming its not a 100 head on a 85 cylinder) and the cylinder bored to 100cc specs and replated, Your second option would be to purchase one already done. Check out Eric's garage sale items. He typically has 100cc cylinders ready to go. There are others that can do the same job but I haven't seen anyone with more reasonable prices or better service.
Complete KX100 top ends are typically in the $400 range form Eric and come ported to suit your preference.
