I don't recall seeing an O-Ring for the orfice in either of the two Hypertech M systems I have purchased. The owner of the Hypertech M in question didn't think he had an O-Ring for the Kline valve seal either.
Maybe this is a recent change? I'll have the owner double check his O-Ring kit.
Thanks for addressing this. We should have checked for this O-Ring but made a bad assumption that it was factory installed. Will the manual be updated to show this O-Ring for the M motor? Neither I nor the owner of this motor saw tis O-Ring in the manual.
Brian Elfert