Other than pulling the heads none that I know of.Try pouring ATF and kerosene in the cyls.That might break it loose.Let it sit for a day and try turning one way then the other and see if it turns.Keep trying for probally a week.Ive had a few motors that freed up using that combo.Seems I had a super long wrench that I used to be able to slip down in and get them loose no matter where they were.Rocky