motoz/HMF
10-24-2005, 10:42 AM
Most all utility quads have an automatic transmission, doing a throttle chop/plug check requires doing things a tad different.
The basics:
Throttle position is throttle position, automatic or manual trans.
Doing a throttle chop on a auto will require that you let the engine and transmission settle out to the throttle position RPM.
EXAMPLE: Say you had access to a highway all to your own to test on with 10 miles of straight.
IF you ONLY held the thumb throttle at 1/4 position and took off the machine would pick up speed then settle to THAT throttle position RPM, same for 1/2 and wide open throttle positions (the higher throttle positions will take a bit longer to get "settled" to that throttle position RPM thus the longer straight needed)
EXAMPLE:
Let's check the needle clip position.
You will need a really long SAFE straight to test on.
Visualize where 1/2 throttle will be on the thumb throttle because you will need to keep it in this throttle position until the engine rpm's settle out.
(visualize the throttle into 3 positions, about 1/4 position to check the fuel screw/pilot jet//green mode on optimizer, 1/2 throttle to check the needle clip position/ yellow mode on optimizer, and a tad over 3/4 to check the main jet/red mode on Optimizer
Start out and hold the throttle at 1/2 position, it will accelerate then the engine rpm will settle out to the throttle position, wait for about 10 seconds then WHILE KEEPING THE THROTTLE IN THE SAME POSITION, hit the kill switch, KEEP THE THROTTLE IN THE SAME POSITION UNTIL YOU COME TO A STOP.
IF you do not keep the throttle in the same position until you come to a stop you will not be checking that throttle position in the carburetor circuit.
Remove the spark plug (s) and evaluate them, then if needed make the adjustment then RE CHECK the adjustment to verify the change was correct.
This is why just "pulling" the plugs after a ride is NOT a true "reading" of a specific throttle position or circuit of the carb, it basically tells you nothing !!
Spark Plug reading picture thread:
http://www.dragstuff.com/techarticles/how-to-read-plugs.html
ALWAYS, adjust the fuel screws FIRST. If they are not adjusted properly you will have problems.
ALWAYS adjust the fuel screw (s) for the conditions of the day and at operating temperature.
Fuel screw adjust thread:
http://hmfengineering.com/forums/showthread.php?t=118
********ALWAYS wear the proper safety gear when doing a throttle chop/plug check, do your testing in a SAFE CONTROLLED RIDING area where the high speeds needed to do the test will not be dangerous to you and others. Be carfuel of removing spark plugs, the engine and related areas will be exceptionally hot. IF you have ANY DOUBTS on your ability to preforn this test have a qualified dealer do it for you..******
The basics:
Throttle position is throttle position, automatic or manual trans.
Doing a throttle chop on a auto will require that you let the engine and transmission settle out to the throttle position RPM.
EXAMPLE: Say you had access to a highway all to your own to test on with 10 miles of straight.
IF you ONLY held the thumb throttle at 1/4 position and took off the machine would pick up speed then settle to THAT throttle position RPM, same for 1/2 and wide open throttle positions (the higher throttle positions will take a bit longer to get "settled" to that throttle position RPM thus the longer straight needed)
EXAMPLE:
Let's check the needle clip position.
You will need a really long SAFE straight to test on.
Visualize where 1/2 throttle will be on the thumb throttle because you will need to keep it in this throttle position until the engine rpm's settle out.
(visualize the throttle into 3 positions, about 1/4 position to check the fuel screw/pilot jet//green mode on optimizer, 1/2 throttle to check the needle clip position/ yellow mode on optimizer, and a tad over 3/4 to check the main jet/red mode on Optimizer
Start out and hold the throttle at 1/2 position, it will accelerate then the engine rpm will settle out to the throttle position, wait for about 10 seconds then WHILE KEEPING THE THROTTLE IN THE SAME POSITION, hit the kill switch, KEEP THE THROTTLE IN THE SAME POSITION UNTIL YOU COME TO A STOP.
IF you do not keep the throttle in the same position until you come to a stop you will not be checking that throttle position in the carburetor circuit.
Remove the spark plug (s) and evaluate them, then if needed make the adjustment then RE CHECK the adjustment to verify the change was correct.
This is why just "pulling" the plugs after a ride is NOT a true "reading" of a specific throttle position or circuit of the carb, it basically tells you nothing !!
Spark Plug reading picture thread:
http://www.dragstuff.com/techarticles/how-to-read-plugs.html
ALWAYS, adjust the fuel screws FIRST. If they are not adjusted properly you will have problems.
ALWAYS adjust the fuel screw (s) for the conditions of the day and at operating temperature.
Fuel screw adjust thread:
http://hmfengineering.com/forums/showthread.php?t=118
********ALWAYS wear the proper safety gear when doing a throttle chop/plug check, do your testing in a SAFE CONTROLLED RIDING area where the high speeds needed to do the test will not be dangerous to you and others. Be carfuel of removing spark plugs, the engine and related areas will be exceptionally hot. IF you have ANY DOUBTS on your ability to preforn this test have a qualified dealer do it for you..******