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- Performance Modifications & Enhancements ( https://www.xt660.com/forumdisplay.php?f=52)

- - AIS Removal ( https://www.xt660.com/showthread.php?t=52)

DISCLAIMER: YOU DO THIS AT YOUR OWN RISK AND MAY VOID THE MANUFACTURERS WARRANTY.

AIS Removal/ Disable:
To disable the AIS all you need to do is disconnect the blue plug that comes out of the top of the pump which is located behind the horn.
http://www.xt660.co.uk/attachment.ph...1&d=1147380484

Unfortunately the only way to do this is to remove the seat, side panels, tank panels and then unbolt the tank. Instructions for removing the panels can be found in your Yamaha owner�s manual.
Do not disconnect the fuel lines to the tank, you should be able to slide the tank far enough back to give you access to the pump.

http://www.xt660.co.uk/attachment.ph...1&d=1147381020

Disconnect the blue connector, i used some electrical tape and taped over the exposed connector on the pump. Then I used some Vaseline and covered the end of the connector

http://www.xt660.co.uk/attachment.ph...1&d=1147381020

DISCLAIMER: YOU DO THIS AT YOUR OWN RISK AND MAY VOID THE MANUFACTURERS WARRANTY.

Quote:

Originally Posted by JMC

DISCLAIMER: YOU DO THIS AT YOUR OWN RISK AND MAY VOID THE MANUFACTURERS WARRANTY.

A BIT OF BACK ROUND

AIS :air induction system burns unburned exhaust gases by injecting fresh air into the exhaust port , reducing the emission of hydrocarbons.
When there is negative pressure at the exhaust port the reed valve opens allowing secondary air to flow into the exhaust port.
The system also has an cut off valve that is controlled by the signals from the ECU.The cut off valve opens to allow the air to flow during idle and closes to cut off the flow when the moto is being driven.
However,if the coolant temperature is below the specified value the valve remains open and allows the air to flow into the exhaust pipe until the temperature becomes higher than the specified value.
Also if you unplug the AIS there is a mechanical function as well, where it drags in air when there is a vacum in the exhaust. e.g. on R1 and other yam bikes they disconnect the hoses and block the holes.

Quote:

Originally Posted by Kev

So Kev, from your experienced point of view, would you reccomend the xtx's to have the ais disconnecter or not? because this very issue has been bouncing back and forth, amongst many people. PDQ Dyno said it makes no difference and its ok to have it d/cctd while someone else said its worth having it connected. Whats your idea on this?

Quote:

Originally Posted by CaptMoto

If you are running with after market pipes, there would be no advantage in running a secondary air system to burn hydrocarbons. Because there is no Caterlistic converters.

The way the AIS is set up, it is only for emission control & should have no effect on the running of the bike unless you are running with STD Pipes.

Something I was thinking about, if you block off the pipe from the airbox to the AIS, if it would change the air pressure in the airbox. In theory as the AIS runs it will cause a lower depression in the airbox affecting the air pressure sensor, a flat spot as you crack the throttle. Would be an idea to get someone to try my thought in practice, on the Dyno. With the air pipe blocked then unblocked to see if it makes any difference.

If you are running STD pipes I would not disconnect the AIS. You need to heat up & burn off the Cat for the exhaust to run correctly.

Im sure johnny has has run his bike on the dyno with and without the AIS ,I cant remember what his post was on the outcome,Im sure there was no benifit eitherway though.

Quote:

Originally Posted by Buck

Im sure johnny has has run his bike on the dyno with and without the AIS ,I cant remember what his post was on the outcome,Im sure there was no benifit eitherway though.

Did he block off the air pipe from the airbox to the AIS or did he just unplug it?

Quote:

Originally Posted by Kev

Did he block off the air pipe from the airbox to the AIS or did he just unplug it?

sorry thats as much as i know,hopefully johnny will reply to your post or maybe PM him.

Can I add something else to the mix. As a part time thing, I have been collecting stacks of information about exhaust systems and their design.

One very interesting thing I came across is where some exhaust builders actually drilled small holes in the header pipe, to induce air to the exhaust flow.

The theory behind this has nothing to do with the catalytic converters, but actually to boost power output. The air, or rather O2 introduced into the header, would ignite some of the unburned fuel, and actually speed up exhaust flow. It also increased exhaust temperatures, and the hotter the exhaust gas, the faster if flows.

Some racers even go to the extend to wrap the headers with exhaust wrap, to maintain exhaust gas temperatures and flow, and this wrap actually works. The hole in the exhaust is just another way of doing something similar.

The way I understand it, the AIS will close at the right temperature, or high RPM. Has anyone tried running the motor with the AIS either on, all the time, or, the hole open, to see if it actually boost flow, and maybe increase high end RPM power output? It might just be worth while leaving it open.

I have no idea what the end result will be, or if it will be bad for the stock pipes, but on an aftermarket exhaust, it might be worth while trying it.

There are a doubt in my mind....

If a disconnect the AIS plug, its generate a error code on a ECU system?

No it doesn't display any error messages. So don't worry about it.