Like the title says, I bought a non-running LT250R that had a top-end seizure. When I tore it down, the piston had Wiseco part # 556M06900 on it. Wiseco part lookup says this is a Tecate 4 piston. Has anyone else used this piston or had a quad with it? I already bought a Wiseco 552M06900 but it doesn't have the same intake port cuts so I am wondering if the cylinder porting was modified as well.
According to what I'm seeing online, that is a 71.6mm piston. Are you sure it's an '87 engine? 1987 and up have 67mm std bores and '85 and '86 LT250Rs have 67mm std bores.
Pretty sure yes. Not sure what you found that syas it's 71.6mm though, wiseco part numbers show the size at the end... 556M06900 is 69.00mm which is what the bore measured. The new piston (552M06900) is also 69.00mm and appears to be the same as far pin height, and ring location but does not have the same intake port cuts. I have modified the piston to match the 556M06900 now and everything is working well. Just thought people might be interested in this as it seemed odd to find the Tecate part number in this LT250R engine, it has been bored, possibly even sleeved at some point though I'm not certain of that.