Hi All

Im replacing the piston in my 2013 ossa tr280.

I am having trouble finding an oem piston kit anywhere. I did notive that there is a s3 racing piston kit available - has anyone had any experience with this kit?

I am also replacing the cylinder or perhaps sending the bore away for rechroming. Its about the same price either way- any thoughts?

Thanks for your time

Gene

Great. 

Thanks for that fantastic advice.

S3 piston measurements in the new cylinder should be spot on then?

I just recently put S3 standard (A) into B bore.

I have the very high compression (2013) head and also mine tends to run hot often so it's a good choice to avoid seizure and give the engine more "relaxed" operation (less friction) when hot.

Just check if you see honing marks on the bore (the around 45-degree oval lines) in the working space of piston, if you see those clearly in reflection and you see no excessively worn spots then you're fine without doing re-boring/re-coating, just put in a new piston with rings.

Edited October 2, 20178 yr by tsiklonaut

My 2012 OSSA TRI 280 FACTORY just begin to change sound more like rattling. The engine had never been rebuilt and I fear that it become worn. Before opening I looked for S3 piston and there are 3 size A B C.  how do you know if the size of the piston is A or B or C. The engine have many hours on it. Is it difficult to replace the piston?