blocked ais, still popping on deceleration

ewertkyle

ewertkyle

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I blocked ais hose at air box and pluged air box. When decelerating I still hear popinhsound from exhaust! Help or explanation please!?
 
I originally blocked the hose at the airbox and it reduced the popping by about 70%.

I AM NOT THE ONLY PERSON THAT HAS ONLY REDUCED BUT NOT ELIMINATED POPPING JUST BLOCKING THE HOSE. Have seen quite a few others mention this on the forums.

Then I removed the whole AIS system and used vacuum caps on the covers and now 95% of the popping is gone.

You could also use aftermarket block off plates.


You may have a exhaust leak and that will cause popping. ( probably where the slip-on mounts )

Start the bike and have a friend cover 75% of the exhaust outlet with a towel or block of wood.
Now inspect your exhaust system at the joints and at the head. You will be able to feel any escaping exhaust with your hands.
 
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I get no popping but some backfires on deceleration at 5000 rpm. I didnt like the popping with the AIS after fitting my GYTR slipon and used the factory YEC R1 racing plug set to do my AIS blockoff.
 
Might depend of the fuel map your using. If you run a little fat that could happen. If it pop just a little in one spot just crack the throttle just a bit... it will be all gone.
 
Is your CAT gutted? If so, you will get popping without a Power Commander and proper mapping. super googan nailed most of it.

My wife just installed her CF 2 Bros and blocked the AIS and she's got no popping. She's running a K&N filter, stock airbox and flies. Mine pops a little but it's hardly noticeable except on extreme deceleration. I have the airbox mod, modded flies, K&N and 2Bros with the CAT intact.
 
My FZ1 pops and crackles when I decelerate but I have not blocked the AIS yet. My plan this year is gutting the cat, power commander, Copperdawg modded flies, airbox mod, and AIS block off plates. Expecting block off plates and PC will help eliminate the popping. Don't mind it too much sounds kind of mean when I decelerate, the fuzz dosen't like it much:evillaugh:

Wish some of you guys who have done this lived closer to help guide me through the AIS block off plate process. I will for sure be asking for advice when I start the process.
 
Haven't gotten a pc yet, saving up for pcv, ill check if I have any exhaust leaks and work on removing the entire system with block off plates. I also heard that getting ivans fce would help too
 
ewertkyle said:
Haven't gotten a pc yet, saving up for pcv, ill check if I have any exhaust leaks and work on removing the entire system with block off plates. I also heard that getting ivans fce would help too
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Wouldn't Ivan's FCE make it worse? The fuel cut stops the flow of fuel and Ivan's device is designed to defeat this thus causing more fuel to run through the system. That should equate to more unburnt fuel in the exhaust, thus more popping. UNLESS, you put in the PC and map the excess fuel out. ;)

Forget Ivan's FCE ($200) and a Power Commander ($250), just get the stock ECU flashed to remove all restrictions AND the fuel cut... same price! $450. Plus no need to Dyno the beast thus saving the cost of a few hundred there as well. Hellgate swears by the new ECU. He's a rider I totally trust.
 
Just noticed in your signature that your running no flies and a airbox mod with no power commander. You probably running pretty lean in some areas and a lean condition can lead to popping.
 
FZ1inNH said:
Wouldn't Ivan's FCE make it worse? The fuel cut stops the flow of fuel and Ivan's device is designed to defeat this thus causing more fuel to run through the system. That should equate to more unburnt fuel in the exhaust, thus more popping. UNLESS, you put in the PC and map the excess fuel out. ;)
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People are confusing popping and backfiring !

A back fire is a rich condition build up of excess fuel and a LOUD bang BOOM maybe a few BOOMS.

Popping is a lean condition sounds like pop,pop,pop,pop

backfire = shotgun blast........ BANG
popping = .22 fired rapidly....... pop,pop,pop,pop

So, the popping you are hearing is not back-firing. It is a popping resonating sound generated by a lean condition on decel. When you suddenly close the throttle, the incoming air is choked off and the closed injector also causes the bike to return to idle on the VERY lean idle circuit . However, momentum of the bike is actually "driving" the engine in a sense, and that engine is still spinning at rpm that needs far more gas than the closed throttle can provide. The engine is still spinning but the incoming fuel rate is very low to NONE until just enough builds up in the combustion chamber to fire.. " pop "

THE INJECTORS CUT OFF ON DECEL ON A STOCK FZ1 creating a lean condition ( pop pop pop ) You usually don't hear it with stock exhaust because of the cat.
The AIS system injects even more air in the exhaust making it LEANER causing popping.
The FCE or a flash will keep the injectors on even on decel ( no fuel cut )

So a FCE or flash WILL help reduce or eliminate popping but blocking the AIS is usually enough to eliminate popping if your map is not to lean.

JUST TO BE CLEAR A LITTLE POPPING ON SEVERE DECEL IS NORMAL
 
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yes i need the power commander, i also found a leak because i took my slip on off and didnt slide it back on enoug! leak is fixed, lean bike will be asap. thanks for all the help
 
super googan said:
/ When you suddenly close the throttle, the incoming air is choked off and the closed injector also causes the bike to return to idle on the VERY lean idle circuit . However, momentum of the bike is actually "driving" the engine in a sense, and that engine is still spinning at rpm that needs far more gas than the closed throttle can provide. The engine is still spinning but the incoming fuel rate is very low to NONE until just enough builds up in the combustion chamber to fire.. " pop "


The FCE or a flash will keep the injectors on even on decel ( no fuel cut )
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All this technical stuff and jargon, maps and flashes and FCE's, is way over my pay grade but I do enjoy learning and I am learning.

I had never understood how an excessively lean mix could stay in the chamber and accumulate until enough had gathered to fire and "pop". I really hadn't thought about it until now and then I just assumed the unburned, lean mix would be pumped out on the exhaust stroke. Just thinking about an engine spinning a couple of thousand rpm, I would have figured that the mix would just get flushed on the exhaust stroke but it doesn't. Ya learn something new everyday.

I didn't know the details of the injectors continuing to fire on (no fuel cut) deceleration either. For all I knew, pumping raw fuel into a chamber starved of air would lead to an overly rich mix that would not burn completely and would allow fuel into the hot exhaust system.

Thanks!
 
Essentially what happens when the throttle is closed on decel at high rpm, you get a rush of air into the cylinder/exhaust creating a VERY lean condition. The lean condition creates heat.

The AIS pumping in even more air and makes it even leaner ( and hotter ), not to mention the fuel injectors actually shutting off completely. ( unless you have a FCE/flash )

The SUPER LEAN, o2 saturated environment in the exhaust gets hotter and ignites gasses that would usually not ignite. Actually a miniscule amount of fuel, BUTS ITS SUPER HEATED IN THE LEAN ENVIRONMENT THE OXYGEN SATURATED ENVIRONMENT ALLOWS IT TO IGNITE

Many people are under the false assumption that its a rich environment that creates the popping ( because they hear its unburnt fuel igniting ) So naturally they assume if there is unburnt fuel its rich. What they dont hear is that its such a tiny amount of fuel it would NEVER ignite without a lean, hot, o2 saturated environment.


Ever see all the warnings around an oxygen tank ??? That's because in a oxygen saturated environment things tend to ignite :)...........EVEN THE TINY, LITTLE, MINISCULE AMOUNT OF FUEL IN THE EXHAUST ON DECEL.


Go screw the idle mixture screws all the way in on a bike with carbs. Run that sucker up to redline in 2nd gear and slam the throttle closed if anyone wants to test the lean causes popping theory. :) ............dont forget your ear plugs !!!


On the opposite end of the spectrum a over rich condition on decel can result in a backfire ( not pop,pop, popping ) but a HUGE BOOM.
 
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Recon Viper 1 said:
For all I knew, pumping raw fuel into a chamber starved of air would lead to an overly rich mix that would not burn completely and would allow fuel into the hot exhaust system.

Thanks!
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Really a fine line between to rich and to lean on decel. If it gets way to rich the fuel can collect and give you a HUGE backfire like a cannon going off.

Too lean and you get the little pop,pop,pops as the miniscule amount of fuel ignites in the hotter o2 saturated environment.
 
I have the ECUnleashed reflash with AIS blocked off and a 2 Bros Slip On, gutted cat etc. I still have the popping on decel. I did however install a P1X tip and it helped a lot.
 
kingsxjt said:
I have the ECUnleashed reflash with AIS blocked off and a 2 Bros Slip On, gutted cat etc. I still have the popping on decel. I did however install a P1X tip and it helped a lot.
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A little popping on severe deceleration is normal but if its more than that look for other issues.

Did you just block the AIS line at the air box or use block off plates ? Just blocking the hose only reduced my popping. Capping the system at the valve cover got rid of 95% of my popping.

I would check carefully for a exhaust leak. Usually at the joint with the slip on or sometimes even the exhaust canister it self can leak at the end caps/seams .

I've heard a few others mention popping while running the Two Bros slip on even with the AIS blocked. One guy on the other forum sold it and went with another brand and it cured his popping. May be something with the design of the baffle/canister or a bad seal where it joins the stock pipe.

Many exhaust canisters can suck air in at the seams where the two end caps are.

Unburnt exhaust gases/fuel likes to build up in the muffler/baffle on decel, all it needs to ignite is a little air.

Sometimes a repack of the baffle and a little hi temp sealant around the end caps is cure for popping. Fixed a dirt bike and my buddy's old vmax that way.
 
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I read somewhere, and it may have been on this board, that you can avoid the critically lean mix problem during deceleration by opening the throttle partially and using more rear brake. As the throttle is partially open, you don't go into the lean mixture problem and the popping ceases.

Seems straightforward.
 
Did you just block the AIS line at the air box or use block off plates ? Just blocking the hose only reduced my popping. Capping the system at the valve cover got rid of 95% of my popping.
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That doesn't seem logical unless the hoses leaked. You are effectively doing the exact same thing whether you just plug it or use the plates. Like Hellgate said, the popping is revealed by the pipe. My pipe only has 3800miles on it. I had the AIS active at first and it popped pretty bad. Removed and it got better, but still annoying. When I installed the P1X tip, the popping was greatly reduced and is liveable now. I am saving my rat hole money for a Akra or Suono.
 
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