Fuel mixture appears to be too rich on myHonda lawnmower

Let's focus on adjusting the air/fuel mixture. This adjustment can help balance the fuel-to-air ratio for both cylinders. Here are the steps you can follow:

Idle Screw (Air/Fuel Mix):
The idle screw, also known as the pilot screw, adjusts the air/fuel mixture at idle. It affects the fuel flow from the pilot jets (idle jets) into the carburetors.
Locate the idle screw on your carburetor. It's usually a small black knob near the choke.
Turn the idle screw to achieve the desired idle speed. Listen to how the bike sounds while adjusting it.
Note: Adjusting the idle screw shouldn't significantly affect the mixture setting.

Pilot Screw (Idle Mixture):
The pilot screw (idle mixture screw) fine-tunes the air/fuel mixture from idle rpm up to about 1/8th throttle.
To access the pilot screws, you may need to remove the air box and carb side cover.
The factory default setting for the pilot screws is typically 2.5 turns out.
Carefully screw each one in until it lightly seats closed, and then count the number of turns.
You can adjust the pilot screws to make the mixture richer (more turns out) or leaner (less than 2.5 turns).

Dual Carburetor Sync:
Since your bike has dual carburetors, it's essential to ensure they are synchronized.
Use a vacuum gauge set to synchronize the carbs. Adjust the linkage screw until both throttle butterflies are in the same position for idle2.
Synchronization helps maintain consistent performance between the front and rear cylinders.

Check Rear Cylinder Idle:
If the rear cylinder isn't running correctly at idle, it could be due to a partially plugged idle jet.

Consider cleaning the carburetors if needed. While it can be a bit of work, it's essential for proper performance.
If the issue persists, consult a mechanic or consider opening up the carburetor for a thorough inspection.

Remember to take your time and make gradual adjustments. If you're unsure, consult your bike's service manual or seek professional assistance.

Adjusting the Mixture Screws - VT750DC.com

Carb Cleaning on 03 spirit 750 ' Honda Shadow Forums

Carb Adjustments ' Honda Shadow Forums

Sounds like your fuel air mixture is a little rich. Check your plugs, if they are black you are running rich which will cause some of the excess fuel to be burned off in your exhaust. Two common problems with a bikes fuel air mixture is bad plugs, if one does not fire consistently all the time it will leave excess fuel in the combustion chamber. Another would be a clogged air filter keeping the fuel air mixture unbalanced as well.

Lastly if you are able to, you may adjust your air fuel screws on your carb. However most Honda's are stock with Keihin carburetors and these air fuel screws are plugged so you cannot make adjustments without drilling out the plugs.

white / grey smoke indicates too rich mixture fuel.

lean carb, adjust float, make sure choke is off.

Clean the carburetor ,or the fuel must be adjusted,due to the cold weather the engine need a rich mixture to start the engine,a rich mixture mean more fuel less air

HI how do I set the valve timing on a honda lawnmower mod hrg415c1