Really? How many engines have you taken apart? Been working on my own stuff for 35 yrs. I've taken apart many. 2 stroke, 4 stroke. singles, twins, triples ;4 cylinder and even the old CBX 6 cylinder. I've seen some pretty messed up pistons and the bike still ran.On my current bike, there is some vertical scoring (not major) from the piston and grooves around the top from the rings. Normally I just buy new but this time I want to bore and replate
Wow, so defensive.
It's obviously not as bad as needing a re-bore, or you would be burning blue smoke all day long from the blow-by, have poor throttle response, and it would be way down on power.
...unless you chose not to divulge that.
You are implying that it is not 2 hundreds worth of scoring, so that would indicate that there is no need for an over-bore.
Pistons usually come in 1 or 2 hundreths over-size, to accomdate wear, and still stay in class dispacement size.
Weisco offers sizes from 94.95 - 97.0 mm in 1 hundreth increments. Stock is 95.00.
Now, if you mean a 'big-bore' piston, as in 2mm or larger, that's a different set of circumstances:
You just WANT a rebore and a bigger piston.
Why do you assume that because I have an opinion to your public post, that I have never worked on a motor?