2TS CARB TUNING  By  alleyoop (Read 6,526 times)

If your carb has a SCREW near the AIR FILTER side of the Carb it has a AIR RATIO MIXTURE Adjustment screw.
Turning the Air Ratio Mixture Clockwise RICHENS it Turning it Counter Clockwise LEANS it.

The Idle Speed screw is in the Center of the Carb. Turning that Clockwise RAISES the Idle and Turning it Counter Clockwise LOWERS the Idle.

[RED]IF YOUR CARB HAS A SCREW ON THE INTAKE SIDE GO SEE 4TS CARB TUNING.[/RED]


[blue]ADJUSTING YOUR AIR RATIO MIXTURE:[/blue]



[red]YOU WANT THE HIGHEST RPMS OUT OF THE AIR RATIO MIXTURE SCREW:[/red]

Start your scoot and Get The Engine Nice and Hot about 5 minutes so that the Enricher IF it has one is no longer Allowing Extra Fuel to come in. Then do the following to fine tune the Air Ratio Mixture:
NOTE: The Air Ratio Mixture is very [red]SENSITIVE[/red] and it does not take much to be off so only make small adjustments.

[red]AIR RATIO SCREW:[/red]
FIRST TRY RICHENNG THE AIR MIXTURE FROM ITS CURRENT SETTING:

[blue]RICHEN THE AIR RATIO MIXTURE:[/blue]
1. Turn the Air Mixture Screw CLOCKWISE 1/8 of a turn and wait 10-15 seconds to let the engine catch up with the new setting.
a. If the RPMS go up REPEAT #1 UNTIL the RPMS GO DOWN OR NO CHANGE(then go to b).
b. TURN the Air Ratio Mixture Screw COUNTER CLOCKWISE 1/16 and that should be your highest Air Ratio Mixture setting—GO TO #3.

[green]******[/green]If on the FIRST 1/8 TURN from the STARTING Position IN #1 ABOVE the RPMS GO DOWN OR NO CHANGE , turn the Air Ratio Mixture Screw Back the 1/8 turn to the Starting position and wait 10-15 seconds until the engine catches up -- GO TO #2 [green]******[/green]

[blue]LEAN THE AIR RATIO MIXTURE:[/blue]
2. Turn the Air Mixture Screw COUNTER CLOCKWISE 1/8 of a turn and wait 10-15 seconds to let the engine catch up with the new setting.
a. If the RPMS go up REPEAT #2 UNTIL the RPMS GO DOWN OR NO CHANGE(then go to b).
b. TURN the Air Ratio Mixture Screw CLOCKWISE 1/16 and that should be your highest Air Ratio Mixture setting—GO TO #3.

[red]IF YOU GOT TO THIS POINT AND NOT INSTRUCTED TO GO TO #3 THAT MEANS THERE WAS NO CHANGE IN RPMS FROM DOING #1 or #2 ABOVE, IT IS TIME TO CLEAN THE CARB:
YOU NEED TO CLEAN YOUR PILOT JET AND PASSAGE AND AIR PASSAGES AND THEN START FROM #1 AGAIN.[/red]


[blue]IDLE SPEED SCREW:[/blue]
The Idle Speed Screw on a Carb that are on most 2Ts is in the CENTER OF THE CARB LEFT of the AIR RATIO SCREW.
To Lower the IDLE you turn it COUNTER CLOCKWISE to Raise the IDLE you turn it CLOCKWISE.

3. If after adjusting your Air Ratio Mixture your idle is to fast Turn the IDLE SPEED SCREW COUNTER CLOCKWISE until the Rear Wheel JUST Barely wants to Turn ---GO TO #4.

[red]TEST YOUR ADJUSTMENTS:[/red]
4. Now give the Throttle a QUICK twist and the RPMS should climb up quickly without hesitation or bogging and come down to where you set your Idle at.

[blue]Problems with the IDLE:[/blue]
1. Give the throttle a quick twist:
A. If the rpms drop below idle speed, then recovers (or stalls), it is [red]RICH[/red] —Turn the Air Mixture Screw Counter Clockwise 1/8 turns at a time and go to #1.
B. If the rpms do not drop quickly to the idle speed but hang and drop slowly it is[red]LEAN[/red] —Turn the Air Mixture Screw Clockwise 1/8 turns at a time and go to #1.