Overheated item sparked Adelaide shed fire

A blaze at an Adelaide motor repair business that was initially thought to be suspicious has been traced to an overheated item.

Emergency services were alerted to the fire in a shed at the business in Findon at about 4.30am on Tuesday, the Metropolitan Fire Service says.

The blaze was considered suspicious but investigators have since determined it was accidentally sparked when an electrical item in a boat overheated.

About $300,000 in damage has been done to the shed.

Another blaze in a bus at about the same time in Parafield Gardens remains suspicious.