Triumphrat

10-10-2005

saw many topics discuss how to remove the Bonne T100 AI system , is any one can help to tell me , what's the function of AI and the advantage to remove AI ?? Thank you !! :hammer:

swelebny · 10-10-2005

Greetings, t710391

The Air Injection (AI) system, injects fresh air into the exhaust port. This additional air downstream of the combustion chamber adds oxygen to the exhaust and causes more complete combustion of the gases, resulting in a cleaner running motorcycle. This also causes the exhaust to be quite hot.

If the bike is left stock, there is no harm to leaving the AI system intact that I am aware of.

There are two downsides to the AI system: One, the very hot exhaust causes the exhaust pipes to discolor, otherwise known as 'bluing'. Many people like blue pipes, myself included, but the Bonneville will blue the pipes darkly to the second bend with the AI system intact, and do it pretty quick too.

The AI will also cause excessive 'popping' on deceleration when the bike is modified with aftermarket 'or custom' exhaust and richer carb jetting.

Steve

Shorty · 10-10-2005

t710...removal of the AI will decrease your header pipes from bluing any more than they already are. It will not add any more performance to your bike if you decide to remove it.

Shorty

dazco · 10-10-2005

As said, if you do any mods like pipes and airbox and jetting it'll cause the bike to pop a lot more. But i also noticed removing the AI seemed to make my engine run cooler.

jsdc2005 · 10-10-2005

I noticed a cooler engine too, but mainly because it takes a lot longer to warm up. My choke knob is getting worn out. :wink:

Diego · 10-10-2005

There is exactly one, and only one, advantage: it reduces the tendency for bluing of the pipes.

I'm sorry, but I have to (continue to) say the other two factors mentioned are not quite accurate.

Popping on decel is not inevitable with the AI when the exhaust is modified. If you get the jetting right, it doesn't happen, even if the AI remains. That's how mine is set up and I have no popping.

In addition, there is no physics to support the notion that the <u>engine</u> runs cooler without AI. The additional heat at the exhaust port from the afterburning of waste hydrocarbons is a tiny fraction of the heat energy produced in the combustion chambers by ignition of the air-fuel charge. The pipes will be cooler without AI, but not the engine internals by enough to make any difference.

(There was a post a few weeks back by someone who claimed to have measured the oil temp and cylinder walls with a pyrometer and found a 20 degree difference. I asked whether that was just with AI removal alone or was it after the whole exhaust mod and jetting business, which can affect operating temperature because of its direct effect on the internal combustion process. He never bothered to respond, so far as I can tell.)

Removing AI also has one disadvantage: your exhaust becomes 10 to 20 times dirtier in hydrocarbon emissions. You'll have to evaluate the implications of that for yourself. (Just don't kid yourself that motorcycles are cleaner than cars because they're smaller, though. Not hardly!)

Am I a curmudgeon? Yes and no. I have no problem with people doing whatever they want to do with their bikes. My problem is with the pseudoscience they often use to rationalize it after the fact. I mean, it hasn't been that many months since we had people trying to make others believe it did affect performance; took quite a while to overcome that notion, which can be shown to be goofy with one glance at the service manual.

10-10-2005

Thank you guys to share the knowledge , it's much help and I decide not to remove the AI.

CarlS · 10-10-2005

There is one other advantage that has not been mentioned. With that ugly AI plumbing out of the way, it is much easier to check and change spark plugs. Personally, I like the aesthetics without that unsightly plumbing.

meatwagon · 10-10-2005

Diego ,10 to 20 times more hydrocarbons?I am very surprised if that's true-much more than I would have thought.Or is that without all emission control systems on a Bonnie(including evap loss can)?Where can I find some more information on this and where did you find yours?

Diego · 10-11-2005

> Where can I find some more information on this and where did you find yours?

Gosh, that was from an article I read 20-some years ago when motorcycle emissions were first becoming an issue. (I would guess the EPA has similar records in their archives if one has the time to search.) They were saying tests had shown a 90-95% reduction in unburnt exhaust hydrocarbons with the addition of a simple passive AI system like that used on the Bonneville now. This was on top of the effect of emission control carburetors.