The Viper 3121V Powersports Alarm is super small and water-resistant. It can be used on bikes, jet skis, boats or and other small machines that use a 12-volt battery.
The first thing you notice when taking it out of the box is just how small it is. This makes it super versatile as it’ll fit where most other systems are simply too chunky.
Viper has achieved this but getting rid of all of the fluff you don’t need. Gone are the lock/unlock outputs, but being a Viper you still get an Auxilary output.
Siren or Horn Alarm
The Viper 3121V comes with a small waterproof siren but can be programmed to honk the vehicles horn too. Note that it’s one or the other and not both. The alarm will also flash the hazard lights or park lights depending on how it is wired up.
Tilt and Shock Sensor built-in.
The Alarm has adjustable tilt and shock sensors built-in. The Shock Sensor has 8 sensitivity levels. The Tilt Sensor can be set to trigger at a 1º, 5º, 15º or 30º angle.
Both sensors can be bypassed when arming with the remote.
Auxillary Output
The Aux output is activated by pressing the arm and disarm buttons of the remote together. It can be programmed as a momentary output or a latched output. When programmed for latched, one press turns it on a second press turns in off. There is the option to program for latched which resets when the ignition is turned on.
Closed Loop Sensor
There is a closed-loop sensor which could be useful for attaching around your helmet. The Viper can also be wired to trigger from a switch so that seat covers and such like can be secured for being opened.

Power Saving (Sleep) Mode
There’s nothing worse than going to use your bike only to find it won’t start due to a flat battery. Small batteries simply don’t like a parasitic current draw, for this reason, alone most bike alarms are more trouble them what they are worth.
Fortunately, Viper has this covered with Sleep mode. After 24 hours the LED flash rate slows to every 4 seconds. At 48 hours it drops to flashing every 8 seconds, then after 96 hours of no activity (that 4 days) it goes to sleep.
Viper Video below:
Starter Immobiliser
The 3121V has a built-in Starter immobiliser which is activated when the alarm is armed.
Viper 3121v
RRP with Installation: $500.00
Obsessive Rating:
Sweet as a nut!
The compactness of this is an absolute winner.
The unit is IP66 rated so is verified as waterproof.
Powersave sleep mode is a must if you have a small battery.
OVERVIEW
Features:
- Small Water Resistant Siren
- Shock & Tilt Sensor
- Starter immobiliser
- Loop Sensor
- 2 Waterproof Remotes
- Up to 95m Remote Range
- One Aux Channel
- Valet Mode
Do you guys install in Christchurch?
Hi Zak,
I only cover Wellington and it’s just myself, not a team of guys!
Cheers,
Julian