[MichaelZxer]

Can you damage the engine using a pipe with cat removed, a k+n filter and stock fuel mapping? It burbles, pops on decel which means lean. I bought it with 26,000 kms on it, seems tip top but I was thinking maybe I should get a juice box?

 

[Porschenut]

Isn't popping on deceleration normally caused by unburnt fuel igniting in the heated exhaust? That's where my blue flames come from and my flashed ECU runs rich.

 

[MichaelZxer]

It can be from both apparently? if you are running too rich, the pop will come from the exhaust usually with some flames, too lean and it will pop in the intake. I don't have flames, just lots of popping

 

[gaz]

on that gen 3 u can eliminate that by blocking off or connecting pair valves eliminating oxygen being introduced into exhaust system on deacceleration. just leave pair valve wired up not to throw fi light and connect the two pair valve outlets on top of valve cover with short piece heater hose and couple of hose clamps so airtight-cost couple of bucks takes couple of hours to do yourself.

 

[Snakes709]

Get the Ivans block off kit. It removes the pair valves and comes with a connector to plug in so it wont throw the FI code. This will cut down the decal pops. To answer the original question, no it will not cause harm. You aren't getting the best power/fuel economy but it wont cause any harm. Ran my ZX6R like that for 4 years before I sold it with 0 issues.

 

[LDH]

Let my bro Alex ride it. He can damage any engine regardless of mods...

 

[SkyDork]

Heed the advice from the posts above!

I will add that the "popping" being too rich will not back up into the intake. That's false. If that happens, that is considered a "backfire". That can destroy an engine quickly and is indicative of other serious mechanical issues going on. That's not something that will happen from a cat-back exhaust mod. The exhaust popping is after-firing and is fairly normal due to the emissions controls and the fresh air injection into the exhaust to burn up the unspent fuel. It is corrected partially by blockoff plates and proper tuning. Over time, this behavior can damage the exhaust if it continues. It will degrade the silencer packing. Aside from those things, it's not going to hurt much else in the motor if it isn't back flowing into the engine itself. And that would require you to open the motor and inspect the pieces (valves, pistons, rings, etc).

 

[lun471k]

Heed the advice from the posts above!

I will add that the "popping" being too rich will not back up into the intake. That's false. If that happens, that is considered a "backfire". That can destroy an engine quickly and is indicative of other serious mechanical issues going on. That's not something that will happen from a cat-back exhaust mod. The exhaust popping is after-firing and is fairly normal due to the emissions controls and the fresh air injection into the exhaust to burn up the unspent fuel. It is corrected partially by blockoff plates and proper tuning. Over time, this behavior can damage the exhaust if it continues. It will degrade the silencer packing. Aside from those things, it's not going to hurt much else in the motor if it isn't back flowing into the engine itself. And that would require you to open the motor and inspect the pieces (valves, pistons, rings, etc).

Some people told me on this forum that block-off plates on a gen5 were not mandatory as everything could be regulated/deactivated through a flash... is that right ?

 

[SkyDork]

Some people told me on this forum that block-off plates on a gen5 were not mandatory as everything could be regulated/deactivated through a flash... is that right ?

I don't believe that. The air injection system is still present on the Gen 5. The oxygen sensor will only run the motor in closed-loop mode at part/steady throttle. Once the throttle is opened and power demanded from the motor, the system goes into open-loop and the fueling is based on the target value for throttle position, gear selection, etc and ignores the O2 sensor values. That's when the fuel injection system will primarily be needed and run.

To my knowledge, the reflash can only turn off the caution light associated with the injection valve. It can't control the operation of it. So, you block the ports to keep the fresh air out of the exhaust, and then you can remove the switching valve and reflash the caution light off all the time when it senses the valve isn't there.

 

[Victors]

I don't believe that. The air injection system is still present on the Gen 5. The oxygen sensor will only run the motor in closed-loop mode at part/steady throttle. Once the throttle is opened and power demanded from the motor, the system goes into open-loop and the fueling is based on the target value for throttle position, gear selection, etc and ignores the O2 sensor values. That's when the fuel injection system will primarily be needed and run.

To my knowledge, the reflash can only turn off the caution light associated with the injection valve. It can't control the operation of it. So, you block the ports to keep the fresh air out of the exhaust, and then you can remove the switching valve and reflash the caution light off all the time when it senses the valve isn't there.

At the very least you have to block or cap the inlet house from the air box. SkyDork is correct.

 

[The Prophet]

Exhaust leaks can cause popping too.

 

[scout]

yes, too rich but most likely you're too slow in too high gear. This bike is the in line four. Keep it off the limiter and stop shifting all the time. But buy the extended warranty until we know if our kawa engineers win out over the pantie penny pinchers in the profit department.