AIS, one last time,,,,,

[Guest wrench]

and I promise this will be my last post on this subject. Flame it if you must, but just read it all before you do. After the "healthy" discussion in the previously related post I decided to get an experts view on the AIS. I talked to a factory-cert'd mechanic today and asked him to explain the system in general, not just specific to our Ventures. He said that any changes to the exhaust, from merely drilling small holes in the baffles, to a full-on custom exhaust will cause the injection system to perform at less-than-designed efficiency. The less back-pressure, or restriction down stream will allow more fresh, cooler air to be drawn thru the injection system into the exhaust, thereby causing the detonation of unburned gasses that we hear. He said this was one of the issues that H-D encountered when they introduced the "parade-mode" of dropping the rear cylinder in idling situations to help keep the bike cooler. Add aftermarket pipes and the amount of fresh air being pumped into the rear cylinder increased and caused the same thing we are seeing when the rear cylinder came back up. He said he has tried unsucessfully to fabricate some sort of "orfice" that would restrict the amount of air equal to stock conditions. He said fuel injected bikes were less-succeptible to it, and easier to correct. I asked if he had encountered other problems thru the years that contributed to the problem, and he said "of course", the same as mentioned here, fouled plugs, leaky vac. lines, old fuel, and on and on, but the main problem was the relieving of the back pressure. He's an old-school kind of guy, so I didn't bring up the Polar Bears and global warming.

 

I'm done now.

[1BigDog]

He's an old-school kind of guy, so I didn't bring up the Polar Bears and global warming.

 

I'm done now.

 

You left out "Save the Whales".....

[Seaking]

You left out "Save the Whales".....

 

Sigh... Save a tree.. eat a beaver..

[Jerry W]

I stopped the "noise polution" on my bike by plugging. It was poluting the ears.

[V7Goose]

You can believe what you want - I doubt you will do otherwise. In fact, in the absence of overwhelming evidence, just about all of us will choose to believe the opinions that most closely match our personal desires; that is just human nature. Personally, from what you wrote, it seems to me your "expert" may not have more than a rudimentary knowledge of the subject.

 

You don't need excuses to disable it - it is your bike - do what you want. We have both agreed upon that several times.

Goose

 

 

Before you get upset with me again, please note that the beauty of opinions is that we all get to have one (and they all usually stink to somebody). No mater if I like yours or you like mine, we still get to have it. It doesn't offend me a bit if you don't agree with mine.

Edited August 2, 2009 by V7Goose
Tried to make it less confrontational or offensive

[Guest wrench]

You just keep bitin' at me don't ya Goosey? Okay, sure, rudimentary if that's what you want to call 30 years of owning a factory authorized shop. But then you probably don't believe that either. Geez, I guess I gotta find better things to do with my time than trade barbs with a self-evident mechanical genius! I AM done now. Hey Don, can I get a refund?

[Magnawake]

Wrench, Thanks for checking on this. I feel kinda dense. As I said before, I dont even know what an AIS is and where to locate it. Once I find it, I'll take a break from watching whale Wars and plug that stupid thang. If it stops the poppin I'll be happy. If it still pops, I'll look other places. Thanks for you input.

 

Oh yeah, the whale war captain was so far out in his beliefs, he got kicked out of Green Peace. I know he just cares so much for the planet... They are running twin Mercs ( 2 Stroke, oil burners ) on thier chase boats. Go figure... All the guys I go offshore with run 4 strokes. I dont understand.

[BoomerCPO]

All I know is what I see/feel with my bikes performance both before(Stock) and after I changed the pipes and plugged the AIS......and I'm sticking with the mods I have done.

 

To each his own and keep riding!!

 

Boomer.....riding with 4-2-4's, a plugged AIS, a IPOD with great tunes, and a grin as big as Texas.

[BigSexxy]

Cant we all just get along? COOMBA YA COOMBA YA:225:

[spyderhead]

After changing the filters to K&N, changing the pipes to BUBS, and plugging the annoying AIS, I too am keeping my modifications. The bike runs easier, breathes easier, gets slightly better mpg . . . there is NO downside. This after over 7,000 miles after having done the mods.

[Jerry W]

Wrench,

There are detailed instructions on this site on how to plug the AIS. It is easier to do if you do it when you are changing oil. You simply take the clamp off two hoses and insert a tapered rubber plug. One of the hoses is on the right side back by the shock, it has a gold clamp on it and is the largest hose, the other is on the left side at the front and just above the oil filter.

[1 Canuck]

You just keep bitin' at me don't ya Goosey? Okay, sure, rudimentary if that's what you want to call 30 years of owning a factory authorized shop. But then you probably don't believe that either. Geez, I guess I gotta find better things to do with my time than trade barbs with a self-evident mechanical genius! I AM done now. Hey Don, can I get a refund?

 

Good Post! I always like to read someones opinion, thought, information, or questions. If everyone cared what others thought, there wouldn't be any posts. I guess that is what makes it a community?

 

Keep the posts coming and I'll keep reading.

 

Cheers,

[Eddie Fulmer]

I followed the instructions on this sight and plugged the ais. Not one pop since.

[Magnawake]

I think I was the one that needed to know where the AIS was located. Wrench did some home work on it. Anyway, sounds like something I need to do. We're makin alot of pop corn around here. It's not too bad, but in the decel going down hill, gearing down trying not to burn the brakes its kinda bad. Maybe thats why people were diving into the bushes as I passed. Machine gun Kelly should be my new name.

[V7Goose]

After changing the filters to K&N, changing the pipes to BUBS, and plugging the annoying AIS, I too am keeping my modifications. The bike runs easier, breathes easier, gets slightly better mpg . . . there is NO downside. This after over 7,000 miles after having done the mods.

Uh, . . . No.

 

Like I said above, everybody gets to have their own opinion, and neither I nor you have to agree with any of them. And I wouldn't dream of trying to disabuse you of yours. Your opinion is that your bike runs better with the AIS plugged. BUT, we need to be careful to make a distinction between opinions and fact. This response is only for the benefit of anyone who might be reading this thread and does not ALREADY think they know all about the subject.

 

(I will note here, however, that if you actually meant that those benefits came from the changes to the intake or exhaust, then that might be correct, so I will apologize for misinterpreting your words, just in case.)

 

The fact is, our AIS is a completely passive induction system - no pump of any kind that can have any impact at all on the engine. All it does is allow fresh air to be "inducted" (or sucked) into the exhaust header to allow unburned hydrocarbons to continue burning before they are blown out into our air. The AIS valves are operated by high intake vacuum to stop that air from entering the exhaust header at times when it would cause an afterfire.

 

SO, the FACTS are that it is totally impossible for plugging the AIS system to have ANY effect at all on fuel economy, engine smoothness, "breathing" or anything else that involves the starting or running of the engine.

 

And it DOES have two downside effects:

 

1. Whatever was causing the afterfire to begin with was something wrong with the proper combustion of fuel in that engine. If it is not otherwise repaired, that problem with the bike remains. True, that is not a true direct downside of plugging the AIS, but it is a downside of the decision to do it, non the less.
   
2. Disabling the AIS in any way DOES increase pollution. That is a fact that you cannot deny. You may not care, or you may decide to tell yourself that the amount of pollution isn't a big deal to you, but the fact remains, it is increased. That is a downside for all of us.
   

Goose

[spyderhead]

Bizarre! Assuming there is a difference between "facts" and "opinions" is one of the problems. Usually "facts" are just someone else's "opinions" that you have chosen to substitute for your own thinking. Goose, what IS your problem? Are you just one of those who just HAS to know "everything"? Before you attack anything I say, make D*MN sure you know what you are talking about )IF you ever do).

[footsie]

If the bull gets any deeper on this post someone's going to drown.

 

 

gregg

[SilvrT]

Somehow I missed reading this thread and am just getting into it now (albeit not that old). Seems a little more than heated engine exhaust is flyin around LOL!

 

FACT #1: The AIS injects air into the hot exhaust gas when it exits the cylinder (yes/no?)

 

FACT #2: A leak in the exhaust system prior to the muffler will "suck in" (aka induct) air into the hot exhaust.

 

FACT #3: The result of FACT #2 WILL cause backfiring on deceleration. I know this to be a FACT because that is what happens when the exhaust collector on a 1st gen has holes in it and when you repair that, ... no more backfire.

 

OPINION: FACT #1 and FACT #2 have similarities and therefore BOTH could cause FACT #3 (yes/no?)

 

The difference between FACT #1 and FACT #2 is that in #1 the air is induced at the header pipe and therefore does not accumulate as much and also the "backfiring" occurs at that point whereas in FACT #2 the air is induced closer to the muffler, accumulates in the muffler, the "backfiring" occurs there, and is much more evident (louder).

 

(just my "factual" $0.05 cents of "logical opinion")

[footsie]

I talked with Steve from lumber city in ga, his 99 has 239,000 miles on it, the ais was removed at 600 miles, and mufflers changed, bike has had delo 400 15-40 oil since first oil change, the motor has never been worked on, no wenching has been on his bike except to change oil every 7500 miles, air filters serviced every 25000 miles, 3 sets of plugs. he said he has never adjusted carbs, valves or anything else on his bike.

Sounded like it was running perfect to me.

 

I beleive I can get mine to 300,000, I change oil every 5000.

 

Gregg

[Ponch]

After having my AIS disconnected for about a year and a half, I hooked it back up after changing mufflers back to stock. It popped and crackled, etc. like crazy. It turns out the carbs and plugs needed attention.

Now it occassionally pops on decel, but usually is pretty quiet. When it acts up again, I know I have problems some where.

[AKRefugee]

He said that any changes to the exhaust, from merely drilling small holes in the baffles, to a full-on custom exhaust will cause the injection system to perform at less-than-designed efficiency. The less back-pressure, or restriction down stream will allow more fresh, cooler air to be drawn thru the injection system into the exhaust, thereby causing the detonation of unburned gasses that we hear.

 

Maybe I'm a bit uneducated here but uhmmm I don't think I have an "injection system" on my bike I believe I have a carburetor. Was the mechanic talking apples to oranges?

[V7Goose]

Maybe I'm a bit uneducated here but uhmmm I don't think I have an "injection system" on my bike I believe I have a carburetor. Was the mechanic talking apples to oranges?

Well, you are right, but we are actually talking about two different things, and the person you quoted was wrong in the terms he used even if his understanding might have been correct.

 

Your bike does have carbs, not fuel injection, but the subject being discussed is the pollution control system called an Air INDUCTION System (not injection). On our bikes, this is a passive system that allows fresh air to be inducted (or sucked) into the exhaust header to reduce unburned hydrocarbons. Many engines use an active injection pump for this purpose, but our engine does not.

 

Many people seem to think that disabling the AIS makes the engine run better, but that is very wrong. It is analogous to thinking that killing the person who sweeps up the road apples behind the parade will make the horse run faster! The AIS has absolutely NO effect on how the engine runs, but it CAN tell you when the engine is not running correctly (kinda like someone seeing that the road apples don't look right).

Goose

[Al Bates]

AIS

 

Less face it, motorcycles and automobile are not allways in perfect tune.

With or with out a pollution system they all produce some sort of pollution.

 

Keeping your engine in the best possible tune will cut down on pollution and increase in performance.

 

There should be no different on how the engine runs with or with out the AIS.

 

The back firing can be fixed just may cost a few bucks.

 

Carburetion plays a large part on these bikes. Keep them clean and make sure you allways us the manufacturer specs. Also goto: http://www.venturerider.org/forum/showthread.php?t=14561&highlight=Poor+performance+rough+idle&page=2

 

I did remove the AIS on my 02 years ago. I decided to remove it because it was added just to meet the us emission laws. I wish I would have tested before and after just to see the difference. I'm sure it would not have been much. I believe a few lawnmowers produce as much hydrocarbons as my bike. I remember after removing the system I found many of the parts had a lot of corrosion in them.

 

I do make a point to keep my engine in the best possible tune at all times. This helps in performance and pollution. Also make sure you use the exact specs from the manufacturer.

Edited September 6, 2009 by Al Bates

[spear]

Check it out!

[ame=http://www.venturerider.org/forum/showthread.php?t=485]Plugging the AIS - VentureRider.Org[/ame]