Hi Guys,

Removed my AIS system today , made a block off plate and hauled out all the hoses and such. I'm now reading that i probably should not have done this with the stock exhaust.

"The AIS (Air Induction System), is a control valve under the left shroud that has the chrome pipe that goes to the front of the head near the exhaust port. It also has a hose that goes to the right front side of the airbox near the airbox door hinges. It can safely be removed too. But it is only advised to remove it if you have an after market exhaust. If you have the stock pipe you need the AIS or else it will ruin the CC in your pipe. The AIS is basically an air pump like pollution control system that injects air into the exhaust for a cleaner burn. To remove the AIS, just unplug it and remove the control valve. Buy or fabricate a plate to block the hole in the front of the head, and then put a rubber 1/2" cap on the fitting on the airbox. Chuck the control valve, hose, and chrome pipe in your junk box with the rest of your take offs. Done deal."

So do you guys think i should put this system back on?
So do you guys think i should put this system back on?
So do you guys think i should put this system back on?
So do you guys think i should put this system back on?


As far as i know i will not be getting a after exchaust in the future.

slane said:

Put it back on if you're not getting an aftermarket exhaust. It's there for a reason.

mwakey said:

what about the airbox flapper and hosing?

Wait....what??? What reason is it there for that effects anything other than adding weight?

How could removing the AIS and running a stock exhaust effect anything in an adverse fashion?

If you remove the flapper valve you are adding air into the system before combustion.

The AIS can only add air after combustion right?

I don't get how the AIS is anything but some piece of politically motivated contraption that offers nothing towards performance.

grendel336 said:

The AIS is used to burn unburned fuel & exhaust gasses exiting from the exhaust port to reduce emissions. Injecting fresh air into the exhaust at that point with signals from the ECU, burns the gas and leaves cleaner gasses to escape through the convertor and out into the air you and I breath. The AIS is also necessary for the life of the catalytic convertor. If you take away the AIS, the exhaust temps will rise due to unburned fuel exiting the engine and clogging up your convertor along the way. I don't know about you, but a new exhaust from Yamaha retails for over $600.00 and the AIS weighs maybe a pound. Is that tiny weight loss really going to make you go faster?

If you want to save some weight, there is plenty of other junk on the bike for you to remove. Also think about how much the rider weighs? You don't see too many fat jockeys racing horses do you? There is a reason for that.

I'm sure the car you drive has nothing installed on it except performance items, right? Better take a look under your hood. Your car has more "politically motivated contraptions" than any motorcycle.

I've owned high tech high performance motorcycles from Yamaha since 1990.

An FZR400 and an R1.

Neither had any such contraption and both lived very long and very high mileage lives.

Is there any other motorcycle on the planet with an AIS type contraption on it?

I see it as a politically motivated contraption that's there to fill some quota for environmental (California type) concerns.

mwakey said:

thanks.

I'll be putting this device back on until the day i may get a aftermarket exhaust.

what is your opinion on a stock bike with the flapper removed and all its components?

Thanks

grendel336 said:

Yamaha Road Star
Yamaha R6
Yamaha WR450F
Yamaha Virago
Yamaha Star V-Max
Yamaha R1

You want me to keep going? Do a Google for "Yamaha AIS"

kawasaki uses it to, i think its called "pair" on their bikes. I took it off my ninja because of all the popping on decel after putting an aftermarket pipe on.

slane said:

I wish I knew more about the stock MAP in the ECU, but I don't. Some say the flapper is part of the AIS and some say it is a seperate system. I tend to believe the flapper is seperate from the AIS. But it could be used in conjuction with the AIS for all I know. I think of the flapper as sort of an EXUP system for the intake air. Seems like the ECU controls the opening of the flapper under certain loads to keep the amount of intake air in sync with the amount of air leaving the engine through the exhaust. So does the flapper coordinate it's opening with the closing of the EXUP valve in the exhaust? Who knows. Has anyone run a stock bike on a dyno with the EXUP cover off and the seat off to watch these two valves in operation under different loads?

So does removing the flapper do any damage to an otherwise stock bike? Probably not, but don't quote me on that... I'm no expert. But I don't think it alone will give you any added performance, if that's what you're asking. Maybe I'm wrong and others are right. Maybe the flapper is more of a noise supressor to make the tree huggers happy. That argument makes some sense too, but I doubt you will get the truth from Yamaha about it if it is.

Funny...I did google "AIS" right after I posted that...and I did see that other Yamaha's used an AIS system.

It's also funny that the very first thing that almost every motorcycle owner does is trash almost all of that stuff right after buying a new bike.

The first mod is almost always the exhaust and an EFI unit that allows for tuning of the air/fuel mixture.

I still don't think there's potential catastrophic damage to be done by removing the AIS and keeping the stock exhaust.

Unless you're running overly rich and there's tons of soot building up in your system I can't imagine damage being done.

And since the vast majority of things I've read state the bike comes lean I fail to see how that can happen.

That being said....I can completely accept the idea of going the safe route and not wanting to tempt fate.

I removed my AIS, and I have a stock exhaust, but I also have an EFI programmer and I glued the flapper down.

Before this time next year I also plan to not be running the stock exhaust either.

grendel336 said:

Sorry dude. I didn't mean to sound like a wise ass. And no, you probably won't do any damage to your stock exhaust over the short term. Over the long term it will degrade your catalyst prematurely, but that may be a long time depending on your riding style (and other mods). But you won't see any performance out of removing the AIS either. It may take away some of the popping noise on deceleration, but I don't consider that a performance boost.

One other thing to consider if you have local emissions tests in your area. Your stock bike may not pass the sniffer test with the AIS removed. I don't know of anyone having this problem yet, just throwing that out there FWIW.

No apologies needed. I didn't take it the wrong way.

I fully agree and understand there's no performance advantage to removing the AIS.

Nothing other than losing weight.

I think its a one pound item, thats silly. The bike WAS lean until you add a programmer and theoretically speaking, your exhaust could eventually turn into a tire fire. You could probably take a poop and save one pound. Seems kinda silly to take that off.

I'm leaving mine on, and the motor basically stock, until the extended warranty is up. Moss-Magnuson act or not, I'm not giving the dealer a reason to not cover a mechanical failure.

I don't see a problem by removing it either, (stock or aftermarket system). This thing only opens during an idle condition to inject fresh air into the exhaust after combustion.....outside the cylinder. Mainly to pass smog testing.
Removing the A.I.S. won't make your bike polute less.....................just fool the Smog testing equipment (at Idle) to make it look cleaner to the meter by diluting the exhaust gas with fresh air. I removed mine to eliminate weight and noticed no increase in power.
I do like to show off my handmade block-off plate to motorcycle friends and BS-Em into thinking I added like 5 HP with this Mod.