runin in a new piston on a cast iron

if you have already run in a cast iron bore and you get a new piston do u need to run it in all over again.

regards owen

 

yeah if you get new rings aswell

 

right i have just taken off my head etc etc after my carbon reeds had broken and my piston is fairly scored but the rings are fine so do you reckon i woud need a new piston and also my cylinder have a few scores how bad is this and is it a big problem?

regards

 

nothing much i dont think i didnt know they could speek :w00t: :w00t: :w00t: :w00t: sorry just had to lol

 

If the barrel is scored, hone it smooth and get the "next size up" piston....known here as a "B piston" or secondary piston.....obviously with new rings.....Don't rev the tits off it for the first 500Km.......well thats how the Nitro's and BWS's are according to Yamaha.

 

Hmmmm...i stand corrected.
If we really must get technical you have to look at feeler guages and ring gaps....
But at the end of the day, suppose honing doesn't take enough material out