Anyone know what this might be for?

[Dan Lee]

So, I just noticed this switch the other day, pretty sure its not factory.
I've only had the bike for a month, I haven't traced it out, but was wondering if anyone had any ideas?

 

[Dan Lee]

Could it be a V-boost switch? Its been in the off position since I've had it.

 

[Fire-medic]

Hoo-hah, you're in for a surprise, if the 'off' position means V-Boost is not activated!

Before you turn on the bike, push the switch to "on." Start the bike. Find a wide, empty road, with nothing on both-sides of the road. Make-sure there is no oily pavement, dirt, dust, or loose pebbles, crushed rock, spilled anything on the road. No nearby traffic. Start out in 1st gear. run it up to 3500-4000 rpm, shift to second. Gradually wind it open, and don't grab a big handful of throttle!

As you pass 5,000 rpm, run it up to about 7,000-8,000 rpm, and as you do it, be prepared for a sudden increase in acceleration, as the V-Boost functions.

Repeat as-many times as your driving privileges and insurance payments can withstand.

 

[desert_max]

Lol. Unless it’s a fan override. I put one on my 94 - but on the opposite side. Had my T-boost switch on the left side...

 

[Dan Lee]

Its already scary in the off position, Is this stock? Or an add on?

 

[Pighuntingpuppy]

Its already scary in the off position, Is this stock? Or an add on?

Add on. Normally the Vboost operates via a controller under the left scoop. Most will put a switch in when the controller goes bad. However....the switch you have pictured is a simple on off switch. I would have to think it is for the fan. The Vboost servo would need another switch to return the servo to the closed position.

But....having said that, someone could have make this a pull only with some sort of return spring system. We dont know what was done to the bike or why. Just best guesses at this point.

 

[Fire-medic]

Add-on. I'd think a fan on/off switch would be on the right side, as desert_max said, because that's where the thermocouple is.

When you turn-on the ignition, but before you start the bike, you should usually hear two sounds:
1] the tick-tick-tick of the fuel pump, for several seconds, it quickly slows, and stops.

2] the V-Boost stepper-motor, a constant whirrrr, a brief stop, then whirrrr-again, and stop, no sound.

If you don't hear these two sounds, 1] your fuel system is already pressurized, and 2] something's wrong with the V-Boost motor

If you kneel-by the left scoop, ear next-to the scoop/steering head, and reach-across the bike to turn on the ignition, you may better be-able to hear the V-Boost motor opening, then closing the V-Boost butterflies.

 

[Dan Lee]

Not going to the fan, attached are a few pictures

 

[Dan Lee]

I can hear exactly what you described when I turn the key on

 

[[email protected]]

It is not stock.
If you pull the faux tank cover (no tools) and the scoop (2 screws) you can take a look and figure it out in a few seconds.

I'd guess its a simple kill switch for vboost being it is on the left side.
It could be a fan switch but the fan controls are on the right side of the bike. But, someone may have put it there so they can keep their hand on the throttle

 

[[email protected]]

Its a vboost switch.
Not sure what type though.
It doesn't look like a simple on/off.
It looks more line a on @ stock RPM and on @ some other RPM.

 

[Zeus36]

It might be a T-Boost switch where the OFF position is used to return to the stock V-Boost RPM setting. ON would place the V-Boost at 3K RPM.

 

[Dan Lee]

I guess thats pretty easy to figure out, v-boost at 3000 rpm verses 6000 rpm. Is it best to just keep it stock, why would you change it

 

[gentsvmax]

SPECULATION IS KILLEN ME!! Trace the wires, pleeeezzz

 

[dannymax]

Nitrous arming switch?

 

[Dan Lee]

I traced the black wire back to the coil,

 

[Zeus36]

I guess thats pretty easy to figure out, v-boost at 3000 rpm verses 6000 rpm. Is it best to just keep it stock, why would you change it

My 1997 has the T-Boost switch, but I don't use it. I'm usually winding it up to redline anyway for shifts or around town cruising between 4K-6K, so no need to have it come on at 3K.

There are many posts on the Pros and Cons of T-Boost here on the forum. To me, there is not enough air flow at the lower RPM to take advantage of supercharging the cylinders with fuel.

 

[desert_max]

There are many posts on the Pros and Cons of T-Boost here on the forum. To me, there is not enough air flow at the lower RPM to take advantage of supercharging the cylinders with fuel.

Uh, you draw twice the air (two venturi) at those lower RPMs with Vboost open, too. I installed T-Boost on my 94 and loved it. And I currently have an On/Off Vboost switch. I like having the flexibility. Have you ever tried it?

 

[Dan Lee]

Not yet! Hoping too, this weekend, not real impressed on there wiring

 

[desert_max]

I traced the black wire back to the coil,

Could be an attempt at a simple t-boost. If the other side of the switch goes to the Vboost controller, he might have tried to directly feed two raw coil signals to fool the vboost controller. Not quite that easy...