I'm a noob with Vboost! Need Help!!

[burgold]

I just got my first Vmax on 11/18/13. I barely got to test ride it as it sat for bout a year, would run with the choke but wouldn't idle without. I am fixing the carbs tomorrow as I am waiting on new float needles. This is not my first bike but definitely the most "powerful".

What exactly is the vboost?:ummm:
Is it a vacuum advance?, or like a power band on a dirt bike? Does it kick in at high speeds or rpm's?, I just don't know EXACTLY what it is!?!

I just don't want to end up with the bike stuck in somebodys car with me stuffed in the airbox!-It'll break my feaux tank!-

The bike is an 85 vmax, 30,000 miles and the engine sounds great. I am looking for information, explanations, adjustments, tips and tricks- I want to be able to explain and fix it by the time I actually take it on my first RIDE!!

Thank you in advance for ANY information!

 

[adambweird]

Vboost is a second set of butterfly valves that open up at 6,000 rpm that allow each cylinder to feed off of 2 carbs insted of one. Kinda works like a 4 barrel carb on a car. Its helps the bike to continue pulling hard all the way to redline. Its not like the surge a GSXR gets when it gets into its power band, but you will notice it! Unless the previous owner had it jetted way too fat, lol.

 

[johnpclynch]

Yup, Vboost sits below the carbs and allows two cylinders to "share" a set of carbs at higher rpm

 

[MaxMidnight]

One of the factors that allow a motor to maximise the torque and power is how well the fuel is atomised in the carburettor.

A high air speed through the venturi will help achieve this.

At a small venturi will achieve this at low revs but as the engine speed increases there will come a point where it can't flow sufficient air and the power will drop off.

You would use a larger venturi to satisfy a cylinders requirements at maximum revs. However, because of the larger diameter then at low revs the air speed will also be low thus the fuel atomisation will be less complete which will reduce the torque available.

The carbs fitted to the Max are optimised for low engine speed but would not be sufficient as the revs rise.

V Boost gives the best of both worlds - at low revs each carb feeds one cylinder and as the revs rise and each cylinder requires more air the V Boost butterfly opens and the other cylinders carb supplies additional mixture.

This maximises the torque available across the rev range.

 

[sdt354]

I am looking for information, explanations, adjustments, tips and tricks- I want to be able to explain and fix it by the time I actually take it on my first RIDE!!
Thank you in advance for ANY information![/QUOTE]

The V-boost was just one of the things Yamaha did to get the top end hp out of the Venture based engine. If you have stock exhaust, the only thing I'd do is make sure it's functioning and adjusted to be fully open, when it's supposed to be. There is an adjustment on the cable that opens the v-boost.
Steve-o