Print Page - R-5 piston marking

Title: R-5 piston marking
Post by: dgorms on June 21, 2020, 03:06:37 PM

I just tore into the top end on my recently acquired 71 R-5, the bike presents as mostly original. I haven't measured anything yet. The marking on pistons is "970" in the back and "613" on one and"614" on the other (at front). The bores look good and minimal carbon on anything. I'm thinking standard, on original bore?....................................D

Title: Re: R-5 piston marking
Post by: SUPERTUNE on June 21, 2020, 06:04:47 PM

Sounds like stock markings to me.
If an oversize you would see a .25,
50,.75 or 1.00 if were oversize in a oem piston top towards the intake side.
Chuck

Title: Re: R-5 piston marking
Post by: dgorms on June 21, 2020, 06:14:07 PM

Thanks Chuck. That's what I thought. There is no other marks except the forward arrow. I did find an oem rd 350 piston in my stash that had "614" stamped on top. Well at least I know I'm dealing with std. bores......................................D

Title: Re: R-5 piston marking
Post by: rodneya on June 21, 2020, 06:18:02 PM

My factory original dykes ring RD350 pistons had 614 and 974 on them.

2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: dgorms on June 21, 2020, 03:06:37 PM