Join spary gun muzzle and recycle hose together (there is a hole on recycle hose). Walnut grit is injected into the engine intake tube and the back of the intake valves through a high pressure air stream for cleaning, the intake valves are closed, and then the walnut powder is sprayed into the engine intake through the air pump (not included) while the HTS558 recycles the walnut powder through the vacuum.
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