Yamaha G2 Carburetor Adjustment & Settings

The Yamaha G2 uses a Mikuni BV26-18 carburetor with a 900 rpm idle, 1-1/2-turn pilot-screw baseline and 14.5 mm float height. Confirm the carburetor ID before using those settings.

Yamaha Carburetor Guide

G2 • Adjustment & settings

Carbureted gasoline version.Applies to

Yamaha 4-stroke gasolineEngine

900 rpmIdle

Pilot screw baseline: 1-1/2 turns out; adjust in 1/8–1/4 turn stepsMixture

G2 carburetor setup at a glance

Model-specific setup

The G2 service data publishes a Mikuni BV26-18 carburetor, 900 rpm idle, 1-1/2-turn pilot screw baseline, 14.5 mm float height and 1.0 mm choke-cable free play.

Carburetor: Mikuni BV26-18

Before adjusting

This page covers the carbureted gasoline version. Confirm the engine and carburetor match this setup before using any setting below.

VehicleYamaha G2

EngineYamaha 4-stroke gasoline.

CarburetorMikuni BV26-18.

Idle speed

900 rpm

Pilot / mixture

Pilot screw baseline: 1-1/2 turns out; adjust in 1/8–1/4 turn steps

Float level

14.5 mm (0.57 in)

Choke

1.0 mm (0.04 in) choke-cable free play

Governor / linkage

Keep the factory governor and linkage setting

Before adjusting

Clean air filter, fresh fuel, correct spark, no intake leaks and free throttle linkage

1. IdentifyConfirm engine + carburetor family

2. Clean and inspectJets, bowl, needle, choke, intake boot

3. Set baselineIdle / pilot / float only from the right manual

4. RecheckWarm idle, takeoff, load response and hot restart

How to adjust the Yamaha G2 carburetor

Confirm this Yamaha G2 matches the carbureted setup shown above. If the vehicle has EFI or no carburetor, do not use these adjustments.

Identify the engine and carburetor before turning any screw. Engine/application: Yamaha 4-stroke gasoline. Carburetor: Mikuni BV26-18.

Before adjusting anything, check fresh fuel, tank venting, fuel-filter and pump delivery, the air filter, intake boot or manifold, spark plug and choke operation. A carburetor setting will not fix a fuel restriction, intake leak or weak ignition.

Warm the engine fully and set idle using this baseline: 900 rpm. Make sure throttle-cable tension or governor linkage is not holding the throttle plate open.

For the pilot/mixture circuit: Pilot screw baseline: 1-1/2 turns out; adjust in 1/8–1/4 turn steps. Only change an adjustment that the exact carburetor is designed to have, and make small changes before rechecking warm idle and throttle response.

For float and fuel level: 14.5 mm (0.57 in). Then verify choke release, hot restart and smooth transition from idle into governed speed without surging, hesitation or flooding.

G2 carburetor symptoms

Runs only with choke

Usually points to a lean condition: dirty pilot and main circuit, restricted fuel supply or intake leak.

Black smoke / rich

Check that the choke fully opens, then inspect float and needle, fuel level and air filter.

Hunts or surges

Check pilot circuit, intake leaks and governor and throttle linkage before changing the idle stop.

High idle

Make sure cable tension or governor linkage is not holding the throttle plate open.

Stalls when warm

Check pilot passage, idle baseline, valve or compression condition and heat-related fuel restriction.

Bog when throttle opens

Inspect transition/main circuit and fuel delivery; an idle adjustment will not fix a blocked main jet.

G2 carburetor specifications

Applies to: Carbureted gasoline version.

Engine: Yamaha 4-stroke gasoline.

Carburetor: Mikuni BV26-18.

Idle: 900 rpm.

Mixture: Pilot screw baseline: 1-1/2 turns out; adjust in 1/8–1/4 turn steps.

Float: 14.5 mm (0.57 in).

Choke: 1.0 mm (0.04 in) choke-cable free play.

Governor: Keep the factory governor and linkage setting.

Model-specific note

The G2 service data publishes a Mikuni BV26-18 carburetor, 900 rpm idle, 1-1/2-turn pilot screw baseline, 14.5 mm float height and 1.0 mm choke-cable free play.

Yamaha G2 carburetor FAQ

What is the correct Yamaha G2 carburetor idle setting?

900 rpm. This is the model-specific baseline shown for the applicable carbureted version.

What is the Yamaha G2 mixture-screw setting?

Pilot screw baseline: 1-1/2 turns out; adjust in 1/8–1/4 turn steps.

What is the Yamaha G2 carburetor float setting?

14.5 mm (0.57 in).

Why does my Yamaha G2 only run with the choke on?

That usually means the engine is running lean because of a restricted pilot and main passage, weak fuel delivery or an intake leak. Clean and diagnose the carburetor before simply richening the mixture.

Can the governor make a Yamaha G2 look like the carburetor is out of adjustment?

Yes. Incorrect cable or governor linkage can hold the throttle open, cause hunting or limit throttle travel. Confirm linkage movement before changing carburetor settings.

What should I check before rebuilding the Yamaha G2 carburetor?

Check fuel quality, tank vent, filter and pump delivery, air filter, intake leaks, choke operation, spark plug, valve or compression condition where applicable and throttle and governor linkage.

Match the carburetor to the exact vehicle

Idle RPM, pilot screw baseline, float height, jetting and governor and linkage settings can change by engine, carburetor and model year. This page applies to the carbureted gasoline version. Verify the engine and carburetor ID before changing settings, and use the factory service manual for any value not explicitly listed here. For manufacturer documentation, visit the official manufacturer website.