[hall_philip]

ok I had been checking my ring end gap on my 09' 250x, the specs in the Honda manual are a lot larger than my readings. top ring says it supposed to be .015" and oil rails say .035". is this like a max tolerance or should I grind them to what the book says? I'm getting .010 on the top ring and .020 on my oil rings.

[crfsonly]

here's a how-to on installing a piston (it's for a 450 but the process of ring gap setting is the same)

http://crfsonly.com/howto/450x/top-end- ... rf450r.php

[hall_philip]

thanks ken, I had already referenced that, but when I go to grind them will I be taking it to the exact specs in the book of is there a tolerance? and since this is the piston that Honda had installed, did they fail to check the specs?

[Back2-2]

I believe what you are referring to is the maximum end gap tolerance. As piston rings wear the end gap widens-hence the maximum allowable specification.

[crfsonly]

thanks ken, I had already referenced that, but when I go to grind them will I be taking it to the exact specs in the book of is there a tolerance? and since this is the piston that Honda had installed, did they fail to check the specs?

my apologies for not reading carefully your question. review the service manual at the begining of the Cylinder/Piston chapter for Piston Ring End Gap. It will have the "standard" gap range specs and the "service limit" spec. for the '09 they are:

Top Ring: Standard: 0.15-0.25(0.006-0.010) Service Limit: 0.39(0.015)

Oil Ring: Standard: 0.20-0.070(0.008-0.028) Service Limit: 0.90(0.035)

So, you want to gap them in the standard range and if the gap exceeds the standard range you would replace them on or before the gap reached the service limit.

Hope this helps.

Ken

[hall_philip]

yes yes, thank you very much. lol I really couldn't see Honda putting something in there bikes that was out of spec. those numbers put me back in the tolerances I needed.