No need to remove the engine. The clutch disc being installed backward is a common mistake, and the wrong throw-out bearing is another possibility. The clutch disc should be marked with something like 'Flywheel Side.' Also, one side of the hub stands up from the disc more than the other side- that side goes to the pressure plate. You have to remove the transmission for either the throw-out bearing or the disc issue, but you don't have to remove the engine. Even if you find the throw-out bearing is the wrong one, I would suggest checking that the clutch disc is installed correctly before re-installing the transmission. That is a small additional effort that may save you removing the transmission again.
Harvester
