I had my cylinders bored .020 over and when i got them the guy told me i'd have to file my rings.Now in my clymer manual for a 75 sportster 1000cc says 0.015-0.025 max for ring gap.Ok so i go to set everything up like the manual says for fileing the rings but turns out the top ring .045 gap middle .032 gap oils .045 and i didn't file them min is .015 so that there would cause piston rock anything over .025 need new pistons and i just got them when i had my cylinders done so anyone have any ideas

 

Ring end-gap and piston skirt clearance are two entirelydifferent dimensions. If the ring gaps are beyond the max, then the rings shoudn't be used or you'll end up with high crankcase pressure, oil consumption and potentially burned pistons.

You'd best have the cylinder bores checked with an inside michrometer and verify the skirt dimensions on the pistons (opposite the wrist pin) before you slap that thing together.

 

ok well looks like a trip back to the harley shop where they were done

 

ZD is correct, '75 Sporty should have .004 piston to cylinder clearance, the rings should be around .010 to .015 gap. A rule of thumb is .004 clearance for every inch of bore.

 

well had them checked out cylinders piston to cylinders spent about two hours and the last thing they checked was the rings.Turns out they pulled several boxes of +20 and they were marked wrong on the box.So all his stock has to be sent back to hastings the rings that were marked +20 were for a +10 bore

 

Good job....lucky you had questioned the fit....

 

yeah i know she"s all ready to go now i just have to find my wrist pin installer or make one i'm ready