Can you take apart the lower half of the engine without taking the upper half apart.

 

Nope.. Each case half has two studs where the cylinder slips on.Top end has to be removed first then the cases can be split.

 

but can you leave the top end together or do you have to take it apart also

 

Yes and no.. The cam sprocket has to be removed,chain dropped down,4 head bolts removed along with the exhaust,carb,coolant hoses,etc.No room to take a complete cylinder and head from the frame as a unit. The whole engine has to be removed to do this,but the head gasket is trash,can't reuse it. Piece by piece is the way to take an engine apart. The same way it's put together.