Hello to everyone. I've finally got round to performing a compression test on my DT250B (1975).  Obviously a search of this forum site for compression test info brings back loads of hits.  However I couldn't see anything that actually said what is acceptable, unacceptable or typical for that matter.  In my particular case it's a newly rebored and rehoned cylinder with new 1st oversize piston/rings and made 120p.s.i.g.  Does anybody know, is this a 'typical' value for the circumstances I've described and therefore acceptable ?  Thank-you in advance for any info given. Best regards Andy.

That's because it's not a reliable test except with your gauge on your bike they way you kick it.  The gauge makes the most difference in my experience.. 

You can compare your reading today with your reading in the future to judge change...  if you have the same gauge and don't change your test method.

There's a reason Yamaha didn't publish values.  But if you read previous posts you probably saw this already...  I've said it dozens of times.