Motorcraft Carburetor Tune-Up Cleaner PM-3

Ford's PM-3 is a pourable aromatic-hydrocarbon cleaner designed specifically for carburetor and induction-system cleaning in gasoline engines — not for diesel or EFI systems. The formula dissolves gum, varnish, and fuel residue from carb passages, port areas, and intake valves. The label's pour-through method involves warming the engine to operating temperature, gaining throttle-body access if needed, then slowly pouring the cleaner through the induction system while maintaining idle — the final pour stalls the engine and soaks combustion chamber deposits. The aromatic-solvent base (30–45% total aromatic naphtha) is an aggressive deposit cutter; the 2-butoxyethanol coupling agent improves wetting on metallic surfaces and fuel residue. Post-clean, aromatic naphthas evaporate within a few minutes of air exposure. The formula is not marketed as O2-sensor or catalytic-converter safe — the label directions include a note to avoid catalyst overheating during the pour-through procedure.

The right buy for a home mechanic with an older carbureted gasoline engine — Ford, Lincoln, or Mercury models where an OEM-approved cleaner matters, or any gasoline-engine vehicle where carburetor gum buildup is causing rough idle, hesitation, or starting difficulties. Also appropriate for pour-through induction cleaning on throttle bodies and port areas. Skip it if your vehicle is diesel, if you want an aerosol spray-can application, or if the carburetor has years of heavy lacquer varnish from long-term fuel stagnation — that level of deposit typically calls for an overnight dip soak or ultrasonic cleaning rather than a pour-through.

The SDS §2 signal word is DANGER, driven by health-tier H-codes: H311 (toxic in contact with skin, Category 3), H304 (aspiration hazard Category 1 — may be fatal if swallowed and enters airways — do not induce vomiting), H319 (serious eye irritation), and H351 (suspected carcinogen). The SDS §15 confirms a California Prop 65 warning — 4-methylpentan-2-one (MIBK family) is listed as both a carcinogen and developmental toxin. Nitrile or butyl rubber gloves are the chemistry-indicated minimum per SDS §8; safety glasses with side shields are directed for eye protection. The SDS §8 respiratory guidance specifies an approved respirator when engineering controls cannot maintain concentrations below occupational exposure limits — SDS §7 directs use with adequate ventilation and to avoid breathing vapor. VOC is approximately 413 g/L (44% by weight at 0.94 g/mL density). The product is classified as aquatic chronic hazard Category 2 (H411) — do not allow runoff to drains or waterways.