K&B and MECOA offered two versions of this engine. One was the ringed .61 and the ABC version known as the twister head. The ringed version has head fins on top while the Twister head doesn't, it has two holes for a pin spanner. I own two ringed versions and I love using them as they're good power , extremely reliable and are just plain simple to use. I never had mine apart but I will say that according to the exploded view, it shows no head gasket. K&B did this also with the Sportster series engines where no gaskets were used. Is your ring possibly stuck? They don't offer too much compression initially until they get a bit of oil on them. These are not Dykes ringed engines but they feel similar when flipped over.