[Blazint]

Hey everyone,

I just installed recently a Devil racer series slip-on exhaust. After the quick install I went out and tried it out to see what it was like. It had the low grumble that i was looking for, but i noticed that when i was engine breaking I could hear the motorcycle backfiring. I wasn't sure at first, but when i came to a neigborhood, i reved the throttle and looked at the exhaust.
As the RPM's came down, i saw a ball of fire shoot out of the exhaust pipe. Does anybody have anythoughts to what i can do to fix this. I am assuming that since putting on the slip-on, my engine is now running rich. From my limited knowledge base, i uderstand this to be bad for the motor... and i love my sixxx, so i dont want to do any damage. PPLLLEASE HELP!

 

[CJr605]

My pipe backfires from time to time and so do some of my buddies pipes. I dont really consider it a big deal maybe it is im not sure. I am also curious on more info on the subject.

 

[Noleman]

It not a big deal and it's not a "backfire." All it is, is the fuel that doesn;t get burned up in the motor getting pushed out of the exhaust valves and igniting in the hot pipes. Running rich is not a bad thing persay. And I doubt you're running rich anyway. If you are running a bit rich, it's okay. The bike will run a bit cooler and you may get the occational fire ball. Don't worry about it. The ECU will figure out the ratios. Go watch some racing and you'll see it everywhere on the track.

 

[Blazint]

Will the ECU start to reconfigure to the exhaust? The only reason i thought it would hurt the motor was the fact that running rich or lean in a car can eventually hurt the engine... more so with being lean. Anybody else have this issue with their bikes?

 

[Dickdaney]

What you're experiancing is completely natural. In fact it was happening before you replaced the stock exhaust. You never noticed it before, because of the restrictive sound surpressing can. What is happening is unburned fuel is mixing with fresh air in the exhaust pipes. When the fresh air hits the exhuast it heats up and ignites the unburnt fuel. That's the "backfiring" you're hearing. The Big Four, and all motorcycle companies do this to control emissions so the Feds don't fine the hell out of them. It's commonly refered to as the "Pair" system. The "backfiring" cause the unburned fuel to ignite and burn, which reduced smog emissions.

The most common way to solve this is to install "smog block offs"
http://www.kneedraggers.com/details/Graves_Smog_Block_Off_Plates_Yamaha_R6--509064.html

They will prevent fresh air from entering the exhaust system and igniting the unburned fuel. This will significantly reduce the "backfiring," But Al Gore and the global warming crew will be mad at you because you'll be pumping more smog into the air.

It's highly unlikely that the bike is running rich. Almost always this is cause by the bike running lean. If you want me to explain why this is, just let me know. You're not going to hurt the bike. In fact you can keep people off your ass by opening the throttle up and closing it really fast, then watch the ball of fire shoot out the can right into the face of whoevers on your ass.


Disclaimer:
I am in no way promotting kneedraggers. They were the first site that came up when I did a google search.

 

[Andrew]

Nice bit of info there, thanks!

 

[hector113]

Normal for the devil. I cut mine down and it looks and sounds better.

 

[R6aven]

love my devil too and the flames..

 

[Blazint]

I'm going to try to take pictures of the bike with the next exhaust. I really like the look of it- i dont know if its just because im prartial to it-but i think it looks a lot better than a lot of other pipes out there. (Devil Racing-carbon fiber- orig. position)

 

[nitrosportman]

yup just some afterburn means those exhaust gasses are movin it may be a little rich most vehicles are built that way better rich than lean though

 

[Owen_R6]

Just like everyone else said...its no problem at all

 

[Blazint]

Another question regarding my exhaust:

Does anything need to be changed around for my exhaust? It seems that the Devil Racer is very much a high flow slip-on. Will i lose any power for having what seems to be a 'high-flow' slip-on without making the proper ECU/fuel management changes?

I have always assumed that nothing needs to be changed unless a FULL system is installed, but i wanted to ask just in case i was wrong about the issue.

 

[hector113]

No it wont lose power.

 

[Noleman]

Another question regarding my exhaust:

Does anything need to be changed around for my exhaust? It seems that the Devil Racer is very much a high flow slip-on. Will i lose any power for having what seems to be a 'high-flow' slip-on without making the proper ECU/fuel management changes?

I have always assumed that nothing needs to be changed unless a FULL system is installed, but i wanted to ask just in case i was wrong about the issue.

Nothing needs to be changed. No you do not need a PCIII. The ECU is designed to make fuel/air ratio changes on it's own provided that the O2 sensor is functioning properly.