Jetting and vortip!

Righty, standard piston, stage 2 cam, opened airbox, baffle free exhaust, Jetting is 60/165

With the vortip in the exhaust when the bike gets hot the bottom end is crap, out its awesome. In the top end feels relentless, without the top end feels flat on full throttle.

So do you think this is a case of I need to try a bigger main once more? As the vortip obviously makes the bike a little bunged up so its running richer than it can accommodate on the bottom end, but is it making the top end richer also, but giving it more power?

What is your elevation?

If the top feels good with the Vortip in with the current 165, leave it. The main jet has nothing to do with the bottom end.

It's the pilot jet and fuel screw for idle and just off idle, and the needle position for midrange you need to think about.

What is your current fuel screw setting?

When you remove the Vortip you're leaning out the fuel/air mix because the exhaust is flowing better/more. So if it runs better with it out, that would suggest to me that the pilot system is too rich for the vortip installed, and maybe the needle, depending on exactly where in the throttle range your bottom end is lacking.

You also have to realize you have a stage 2 cam, which is a mid and top end cam. Bottom end might be suffering because of the cam.

Basically, I'm saying

Vortip in = Bottom end is crap, top end is awesome!

Vortip out = Bottom end is good, top end is a little less good.

Now, I live pretty much on sea level, I have completely opened up the airbox, and have the stage 2 cam fitted.

I also swapped the stock filter (cage chopped) for a K&N today, far weaker all round, where i would normally wheelie whacking the throttle open, it bogged completely! So I'm guessing that I really need to upjet a little for the K&n, obviously I'll try and get it working with the vortip out and standard fitler 1st due to the better filtration (k&n came with bike, not really planning on using it!)

The stage 2 cam is a top end cam. It's not surprising that the bottom end has suffered some.

<<<<<<< I also swapped the stock filter (cage chopped) for a K&N today, far weaker all round, where i would normally wheelie whacking the throttle open, it bogged completely!>>>>>>>

Was that with the Vortip in or out?

What configuration are you wanting to run? Vortip in I'm guessing.

I'm thinking with the change in bottom end flow of the Stage 2, your bottom end jetting may be too rich, as evidenced by the Vortip swap in and out, and how it falls to crap after it's warmed up.

Where is the needle clip set?

Where is the fuel screw set? I'm guessing near closed.

With the Vortip in, I would try a 58 (1 size smaller) pilot jet and retune the fuel screw. Try to get the pilot at 2 turns out for best idle and throttle response off idle. Still too rich, try a 55.

I would continue to run the moddified stock cage and filter. Even replace it with a UNI cage and filter eventually.

I'm running it with vortip out, with noise comes power haha. Ill try jetting it up to 170 on the main.

The stage 2 cam feels no different to stock on bottom end in all fairness it only feels like the mid and top are better! The bottom does not feel worse!

and elevation, not far off sea level, 10 metres lol?

In that case, I agree, go up on the main.

I'm running it with vortip out, with noise comes power haha. Ill try jetting it up to 170 on the main.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now