QUESTIONS & ANSWERS 2026 UPDATE | 100%
CORRECT
Engine Models: F9.9B / T9.9B / F9.9LMHS / T9.9ELH (4stroke portable outboards)
SECTION 1: ENGINE IDENTIFICATION & MODEL CODES (Questions 115)
Question 1
What does the "F" stand for in the model code F9.9LMHS?
Answer: Fourstroke
Explanation: Yamaha uses "F" to designate 4stroke engines. "T" is used for highthrust models.
Question 2
What does the "T" stand for in the model code T9.9ELH?
Answer: Highthrust (fourstroke)
Explanation: "T" indicates a highthrust model designed for heavier boats, typically with a larger
lower unit and different gear ratio.
Question 3
What shaft length does "U" indicate in a Yamaha model code?
Answer: 15 inches (ultrashort shaft)
Explanation: U 15", L 20", X 25".
Question 4
What shaft length does "L" indicate in a Yamaha model code?
,Answer: 20 inches (long shaft)
Explanation: Standard long shaft for most 9.9 hp outboards.
Question 5
What shaft length does "X" indicate in a Yamaha model code?
Answer: 25 inches (extralong shaft)
Explanation: Used for boats with higher transoms or specific applications.
Question 6
In the model code F9.9LMHS, what does "M" represent?
Answer: Manual start
Explanation: "M" indicates manual starting. "E" would indicate electric start.
Question 7
In the model code T9.9ELH, what does "E" represent?
Answer: Electric start
Explanation: "E" indicates electric start with pushbutton or key ignition.
Question 8
In the model code F9.9LMHS, what does "H" represent?
Answer: Tiller handle (hand control)
Explanation: "H" indicates tiller handle steering. "R" would indicate remote control.
Question 9
In the model code T9.9ELH, what does "L" represent?
,Answer: Long shaft (20 inches)
Explanation: "L" appears in the shaft length position of the model code.
Question 10
What does the final letter (e.g., "S" in F9.9LMHS) typically represent?
Answer: Model version or generation
Explanation: Letters like A, B, C, or S indicate model revisions or specific market versions.
Question 11
Where is the engine model identification tag located?
Answer: Starboard side of the engine bracket/clamp
Explanation: The metal tag is riveted to the starboard side of the transom bracket.
Question 12
Where is the engine serial number stamped into the engine block?
Answer: Port side of the engine block or powerhead
Explanation: The serial number is usually stamped on a flat area on the port side of the
powerhead.
Question 13
What is a complete Product Identification (PID) number?
Answer: Model code + serial number (e.g., F9.9LMHS + 6AUK1001234)
Explanation: The full PID includes both the model designation and unique serial number.
, Question 14
What year was this engine manufactured if the serial number starts with 6AU?
Answer: The prefix 6AU indicates the specific model series, not the year alone
Explanation: Yamaha model numbers require a serial number lookup for exact year
identification.
Question 15
What is the difference between an F9.9 and a T9.9?
Answer: T9.9 is highthrust with a larger lower unit and propeller
Explanation: Highthrust models are designed for heavier, slower vessels like sailboats and
workboats.
SECTION 2: 4STROKE ENGINE OPERATION PRINCIPLES (Questions 1630)
Question 16
What are the four strokes of a 4stroke engine in correct order?
Answer: Intake, Compression, Power, Exhaust
Explanation: This is the standard 4stroke cycle (suck, squeeze, bang, blow).
Question 17
How many crankshaft revolutions are required to complete one full 4stroke cycle on one
cylinder?
Answer: 2 revolutions (720 degrees)
Explanation: Each stroke requires 180 degrees of crankshaft rotation; 4 strokes × 180 720
degrees.