AIS removal instructions

I own a WR 450 05' and is hard to get this AIS removal kit in Greece.

Can anybody tell what this kit cinsist of.

What should I do with engine connection tubes after AIS removed ?

Should i put plugs to close the holes or connect other tube there?

I will appreciate if anybody can post me a picture how it looks like after modification.


For the most part it consists of two machined aluminum plugs and a rubber slip-on cap.

One small Al plug goen into the hole where the AIS hose connects AFTER the carb.

One larger plug goes in where the AIS hose comes out above the exhaust header connection. The rubber cap goes over the connector where the AIS hose comes from the air box.

The AIS fittings in the engine (2) slide out before the two Al plugs go in.

Toss the AIS in the trash or hang in on wall of your garage to remind you where the clean air folks have taken us.

Thanks for your help.

Do you know what AIS effects, and whats I realy gain after removing it?

Do I need to change anything else?

The AIS is for emissions measured at the tail pipe only. There are no performance advantages if removed. You will notice no more exhaust popping during decelleration which is nice.

Other advantages are a 'cleaner' engine area and easy carb access from the right side which was near impossible with AIS installed.

Less garbage hanging around the engine area.

You asked if anything else needed changed. If you just doing the AIS removal, No.

I assume you did the T-Stop change, secondary silencer removal and grey wire.

If not go here. This is for the WR250 but applies to the 450 too.

A huge difference in performance..

After these mods you will need rejetted.

Look at the 'Free Mods' area.

I went the cheap route to removing my AIS because I wanted a full JD jetting kit instead of the factory replacements. I cut the vacume side hose (small one) a little above the fitting and filled it with silicone, but left the band clamp on the lower side. I then cut the metal tubing about at the first step down from the clamp side. I folded the end closed in a vise, and then brazed it closed. I re-routed my breather tube onto the top (AIS) fitting in the air box, and cut a short piece to cover the lower fitting(Breather)half filled with silicone. Now it should pull air through the filter, and not off the bottom of the air box where water and junk accumulates. Not that you would ever re-install the kit, but now everything would be much easier to put back. It really does not look that bad, and most would not even notice. Mine had only a very minor if at all back fire, but now it makes no extra exhaust noise on decelaration. :thumbsup:

Sure, this isn't the most detailed picture of the AIS removal, but you will notice that the evil little tube no longer exists!

Remove that AIS crap, you will thank yourself for it, the backfiring is annoying as hell.

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