Yamaha F9.9 F15 & Mercury 9.9 15HP 4-Stroke Starter Motor 12V 9T CCW | Replaces 66M-81800-00-00

Starter motor for Yamaha F9.9, FT9.9 and F15 four-strokes and the Mercury and Mariner 8, 9.9 and 15HP four-strokes, an aftermarket replacement for 66M-81800-00-00. Nine teeth, counter-clockwise. Small engines, big market, these little motors move thousands of dinghies and tenders.

OE Reference Numbers

Primary reference: 66M-81800-00-00

Substitute references: 66M-81800-01-00, 66M-81800-02-00

Mercury references: 50-893894

Cross references reported by replacement part catalogs: Sierra 18-6943, ARCO 5359, Lester 18437, WAI 18437N, Arrowhead SAB0182, J&N 410-21094, API MOT3024N, EMP 4-6943

Buyer search terms: Yamaha F15 starter, 66M-81800, Mercury 9.9 4-stroke starter, Yamaha F9.9 starter, Mariner 15HP starter

Reference Specifications

System voltage: 12V DC

Pinion: 9 teeth, counter-clockwise

Rated power: 0.6kW

Pinion OD: 29.2mm

Body: 225mm overall

Mounting: 2 lugs, 8mm holes

Weight: about 2.35kg

These figures come from compatible replacement listings, not from factory drawings. Match them against the removed unit before ordering.

Fitment and Purchase Checks

Yamaha F9.9, FT9.9 and F15 four-strokes, 1998 to 2008. Mercury and Mariner 8, 9.9 and 15HP four-strokes, 1998 to 2011. Check the rear boss before ordering, on this one it sits in the middle of the cover. The 30 and 40HP motor has it on the edge, they do not swap.

Why This Unit

Dinghy starters sit low and get wet. Half the ones we see failed from water, half from sitting unused all winter. Copper windings, coated armature, sealed case. Run the engine once a month and it will outlive the boat.

For Buyers and Distributors

Six months on the warranty, 20 pieces minimum, 10 to 15 days out. If the serial plate is worn off, send a photo of the mounting flange instead.

Aftermarket notice

This listing is an aftermarket replacement part supplied by StarterStock. We are not affiliated with, authorized by, or endorsed by any original equipment manufacturer. OE numbers, model names and brand names are quoted for identification and fitment matching only, and remain the property of their respective owners.