I’m wondering from all your journeymen out there I’m trying to set piston clearances on a 1970 DT1C the book shows 1.6. I believe my machine sinks .002 is about right what do you professionals say thanks for all your help happy new year, merry Christmas, and all that good shit

Hi -
If you meant to type that "your machinist things .002"...." then I would say based on what I have learned and done with my rebored machines is stick to factory clearance because the engineers who designed these bikes know better and that additional slop will cause things to wear out faster.  I would also make sure that whoever you use to bore and hone is familiar with these old 2 strokes, meaning they know how to chamfer the ports....all the folks I have found in S. CA that do this seem to be in their late 60s and 70s.

The bike will run at 0.002 but the ring gap could be in excess of 0.012 which is on the loose end of spec from memory.

At 0.016 the bike should have a tighter ring gap closer to 0.008.

0.016 - 0.008 is close to where I would want to be.

a