How long does it usually take to learn cylinder plugs?

One to three years. It depends on one's learning ability. Strong learning ability, high understanding can start in one year, average learning ability, and average understanding can start in three years. Generally speaking, it takes one to three years to study. The cylinder plug works from the engine cylinder and is divided into two situations. In the engine manufacturing industry, the engine is manufactured from a new engine. The engine blank is processed for the first time to make a preliminary stop, then a fine stop, and finally the cylinder is ground into a finished product. The situation is that the old engine has been used for many years, and the cylinder is too worn, so it is necessary to increase the cylinder to stop it. It is the cylinder plug that does the work.