Tuning Laws

Principles
A fundamental truth as of law.
A given result by it's mechanical contrivance.
Modus operandi that which apply or modifies a mechanical power to produce a certain result.

Flyweight
Ramp profile
Clickers
Temperature
Engagement rpms
Rpms near full shift (spring)
Rpms near full shift (helix)
Upshift rpms (spring)
Upshift rpms (helix)

Flyweight - "Determines rpms" (Example rated rpms 8000)
IF; THEN, Result[s]

Know that 1 gram = approximate 200 rpms change ;  all testing done at full throttle.

  • Need less rpms ; Increase flyweight mass - The TRA lever pushes harder.

Example, IF you reveal 8400 rpms with 40grams flyweight, THEN increase flyweight to 42 grams.

8400 rpms - 8000 rpms = 400 rpms. (1gram = approximate 200 rpms) then you can add 2 full grams and go test at full throttle, what does tach say?

  • Need more r pms; Reduce flyweight mass - The TRA lever pushes less hard.

Example, IF you reveal 7700 rpms with 43grams flyweight and need 8000...

8000 rpms - 7700 rpms = 300 rpms. (1gram = approximate 200 rpms)THEN can reduce flyweight by 1.5 grams to 41.5g and go test at full throttle, what does tach say?

*Let the tachometer tell you what to do regarding changing flyweight.

Ramp profile
"Controls the size/magnitude of the shift force"  (Illustration)
Lower angle will provide more shift force.
Thinner ramp allows the tra lever center of gravity to be farther away from the clutch shaft centerline - Provide more shift force

Higher angle will provide less shift force.
Thicker ramp allows the tra lever center of gravity to be closer to the clutch shaft centerline - Provide less shift force.

Clickers
"Changes TRA ramp angle"   Ramp profile controls the size/magnitude of the shift force.
Determines how quickly the engine will rev/accelerate.
Clicker 6 raises ramp angle to highest point - Quickest engine response
clicker 1 lowers ramp angle to lowest point - Slowest engine response

Learn what your clickers do for 1)rpms and 2) how the clutch shifts.  Cycle them down to 1 and go to 6 and figure out which one allows the cltuch to push the hardest, you feel the best acceleration however have good rpm response when you chop the throttle on off or when the snow load changes.

A rule of thumb is that one clicker change will reveal approximate 150~200 rpms at full throttle. All testing is done at full throttle.  Example - A clicker position is selected that the tuner can use for 80% of their riding.  Now today happens to have over the hood snow that causes the engine rpms to be 200~300 rpms lower than rated.  The tuner can change the clicker to at least one higher number to regain the rpms back.  After a full throttle run, the rpms recover 200 and are at rated again.

When those deep snow conditions are over, the tuner can return the clicker to its previous position to prevent engine overrev.

Really good quick clickers

Temperature
Regardless of temperature you measure, whether its hot or cold or warm or burning or freezing - The lowest temperature you'll measure is when having clutch calibration allow the engine to run at "rated rpms" on a sustained wide open throttle pull.

Engagement rpms
(Primary spring) IF you want to raise engagement rpms, THEN increase the primary spring start force. 
Example going from a ( 160 / 360) to a ( 175 / 360)

(Primary spring) IF you want to lower engagement rpms, THEN reduce the primary spring start force. 
Example going from a ( 230 / 350) to a ( 200 / 350) leaving the final force alone.

(Ramp) Increase ramp angle under roller at the start of the ramp.
Example; IF using a 414 or 415 or 413, THEN change to a notched 419.

Rpms near full shift
(Primary & secondary spring) IF rpms are low or diminish as shift increase, THEN increase final force of the primary or secondary spring.
Example, IF rpms are 250 low while using a (XXX / 300), THEN change the spring to a (XXX / 320).

Rpms near full shift
(Helix final angle) IF rpms are low or diminish as shift increase, THEN reduce the helix angle "at that point" on the helix.
Example, IF rpms start to reduce from rated while using a (XX / 56) degree angle, THEN reduce that angle to a lower one, like a (XX / 52).

Upshift rpms
(Primary & secondary spring) IF rpms are low as sled speed increases, THEN increase start force of the primary or secondary spring.
Example, IF upshift rpms are 400 low and slowly increase to rated rpms when using a (130 / XXX), THEN increase the start force to (160 / XXX).

Upshift rpms
(Helix start angle) IF rpms are low as sled speed increases, THEN reduce the helix start angle.
Example, IF upshift rpms are 200 low with a (44 / XX) start angle, THEN reduce the start angle to 40 degrees (40 / XX)