Yamaha 4 Stroke Outboard Engine Carb Rebuild Series [1] Diagnosis and Carb Removal

Today in part one we will be removing the carburetors on this 50hp Yamaha 4 stroke outboard motor which has a stumble exhibited at all RPM ranges. The Owner having checked ignition already, and the boat being of recent acquisition, its not a bad idea to do a complete workup and inspection of the carbs and make sue everything is functioning properly. The engine model today is a F50TLRB though the process is the same for a range of Yamaha 4 stoke outboards with carbs.

A demonstration of the stumble will be heard before beginning followed by allowing the engine to cool down before disassembly. Pre-marking of fuel hoses are encouraged if you don't remember where they will return, also returning bolts removed to their original position where possible. The top cover of the engine is popped off after fuel hose removal. Any bolts that cant be reinserted are stored in a ziplock bag with removed hose clamps.

YAMAHA CARBURETOR REPAIR KIT MERCURY 40 45 50 HP 4 STROKE 62Y-W0093-11-00
https://amzn.to/3mhxuOH

NON OEM version
https://amzn.to/41i3vVL

Keeping in mind the gas filter and Oil dip stick will be an obstruction, they will be removed from the engine to remove the carbs. The breather hose is held on by a small cable tie. many small cable ties are used as hose clamps throughout this project. The throttle linkage unlocks from the locking tab to disconnect it from the bottom carb.

Ive opted to disconnect the cold start valves from their connectors and not from the back of the engine as a matter of preference. I did pre-label the cables though so it went back to the same position. This was followed by the silencer mounting bolts. and then the carb-inner manifold bolts.

The carb is then negotiated out of the engine manifold with the silencer box and away from the engine. All ports are sealed with clean paper towels. The bag of bolts and clips are stored in the engine cavity and the cover is closed until installation will occur.

Onto Carb disassembly......

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