If you're really sure you knocked off the high spots, that cylinder will likely run o.k.. Amazing how little damage it received considering the piston!
yea..it was one of those deals that I had it wound up cutting off a big limb knot and it just shut off...(i knew that wasnt' good) did the 1/2 mile trek to the truck and i pulled the muffler and seen the damage(metal in the muffler..i knew it was fubared then!) got on the phone and ordered me up my new 660 and picked it up the next day.
It ate something substantially larger than a pin clip.....looks like a carb screw of some kind
well....seeing as i pulled the saw apart and a piece of the broken wrist pin clip was still in the groove that it was riding in kinda told me that it has broken. and the saw was thoroughly inspected and i've rebuilt the carb since then...and rebuilt the saw and ran it a couple hundred hours.
so i would say that between the obvious broken wrist pin clip and no other missing parts that the wrist pin clip caused the damage
Once you oversize the bore at the bottom of the cylinder the piston will rock and the intake skirt will take the flex stress only so long before breaking
I can't wait till you run it so you can blame the cheap piston for the breakage
The fact is with the work your have done and the oversized bore it would come apart no matter who made the piston.
BTW just making the piston lighter will not raise your RPM appreciably but I guess you already knew that
you are missing the intire point behind this whole post...This isn't about trying to blame somebody if the piston fails...this is about me trying to learn something and getting info from knowledgeable people about it on a public forum so that others can learn from it(i'm playing guinea pig here)
and as for the piston..It is from Baileys..they are a great company and i've got an 046BB kit from them that prolly has close to 1000 hours on it and i couldn't be happier with them..i stand behind there products and did several thousand $$ worth of business with them last year. so that being said i think quite highly of their products
as for oversizing the bore..i honed the entire cylinder. yes..it prolly increased the bore several thousands of an inch. and will now allow for an increase in piston movement within the cylinder. but i doubt it is gonna be hammering around in there
i lightned this piston for several reasons...to lower the weight of the reciprocating mass=less stress on bearing, and a faster spool up for the saw (not going for a net increase in rpms, just want it to get the quicker)...and to increase the flow through the piston to help performance...
The entire point of this thread is for me and anybody else that wants to learn from those that know what they are doing and build saws everyday...