restoring an 85 kx250

[85kx250]

i am restoring my 85 kx250. This is my first bike and i had problems with starting. I was told i was loosing compression so i bought a new standard bore piston (wiseco). I put it back together and it fired up. I rode it for a while nd it slowly got harder to start. Well i found out i blew a crank seal so i took it apart and went to get the seals pressed out and decided to get the clearnce checked on the piston. Well now i need to get my cylinder bored .10 over and am wondering if i need to buy another new piston or can i just buy oversize rings.

 

[Sawblade]

Yes, if the cylinder is bored .10 over, you will have to put in a new larger piston to match the bore, plus new rings, top end bearing, wrist pin, c clips and gaskets. If you split the cases to replace the main bearing seals, I would highly recommend with the age of the bike, that you replace the main bearings and have the crank rebuilt while its all apart.

Good luck!