i am at a lost then, when i start with the key, it jumps to 1300-1500 RPM.   If i learn it at 1200RPM, it will not start on some occasions.

If i extend the crank time, can't use the tach, it will be voltage sense only.

There are no threshold option on my viper 5904.

Howie, per the manual

3. Cranking Time

• < lang=KO size=2 face=Futura-Book>< lang=KO size=2 face=Futura-Book>0.6/0.8/1.0/1.2/1.4/1.6/1.8/2.0/4.0 seconds: determines the starter output duration during

cranking for the ‘Voltage’ and the ‘Off’ Engine Checking Mode options

Unless you mean change the

14. Tach Mode Starter Release
1. Normal: the starter output will release normally during cranking (50% of the learned tachometer
value)
2. Increase: the starter output will release later during cranking (at 35% of the learned tachometer
value)
3. Decrease: the starter output will release sooner during cranking (at 35% of the learned tachometer
value)

If i go with Kennys suggestion plus option 2 of the tach mode starter release, 1200-1500 RPM,

1200+35% =1620 RPM to 1500+35%=2025RPM