According to a Baidu expert, the aluminum shell of motorcycle engine can be welded, but the following points should be noted:

1. It is necessary to use welding materials suitable for aluminum, such as aluminum covered electrode or aluminum welding wire.

2. Appropriate welding processes, such as gas shielded welding and TIG welding, should be adopted to avoid oxidation and deformation of aluminum.

3. Aluminum shell needs pretreatment, such as removing oil and oxide, to improve welding quality.

4. The aluminum shell needs proper heating and cooling to avoid the influence of thermal stress.