Yesterday I finally got the free time to install the pair block off plates. Also took the time to wire up a relay for the HID projector lights because the stock wiring doesn't seem to handle the surge of current at start up very well.
Anyway I got everything done and waited 24 hours for the RTV to dry. Fired up the bike a couple times and it idles beautifully. Good.
Spend the next hour putting on the fairings. Took so long because I have to take everything a part after realizing that I forgot to plug the air temperature sensor back in.
After everything is back together, I started it up again. Arghhhh. It doesn't want to start without throttle. Even after it starts, it idles at ~500rpm and dies after a while. I vaguely remember that one need to raise the idle after removing the PAIR system, so I did that and the bike starts and idles beautifully again.
My question is, why would the bike starts and idles fine at original idle setting after the pair blockoff plates are installed but before the fairs are put together? The only difference that I can think off is (1) air temperature sensor was disconnected; (2) lights are not plugged in when the fairing was off.
Now the difference with and without pair: I run straight pipe right off the "udder". With pair, I gets lots of pops on deceleration; without pair, the pops are gone. Hard to say if it is smoother, but I did still experienced a bit of surge after the pair removal. Overall it is definitely an improvement over stock.
excuse my ignorance, but how is not idling, no difference in smoothness with surging an improvement on stock?
Is there enough betterment to justify the effort?
thanks.
timmythecop, removing the pair system did get rid of the popping on deceleration, so it is an improvement for me. Plus less weight, if that matters on a 500lbs bike.
[image: View Post]wshtb, on 17 June 2012 - 12:59 PM, said:
timmythecop, removing the pair system did get rid of the popping on deceleration, so it is an improvement for me. Plus less weight, if that matters on a 500lbs bike.
Did you say you have modified exhaust , cause I get zero popping on decel with stock config and everything Hooked up from the manufactuer?
I have modified my exhaust and installed the A&A pair block off plates with NO popping.
[image: View Post]spud786, on 17 June 2012 - 03:55 PM, said:
Did you say you have modified exhaust , cause I get zero popping on decel with stock config and everything Hooked up from the manufactuer?
Yes, I ran a short straight pipe off the catalytic converter. Lots of popping on decel until PAIR removal.
[image: View Post]wshtb, on 17 June 2012 - 12:42 PM, said:
My question is, why would the bike starts and idles fine at original idle setting after the pair blockoff plates are installed but before the fairs are put together? The only difference that I can think off is (1) air temperature sensor was disconnected; (2) lights are not plugged in when the fairing was off.
Here's the deal.
The PAIR system is basically open all the time except when the O2 sensors kick in. When the PAIR system is open (i.e. all the time at idle), it raises the idle speed of the engine. When it is blocked off, it lowers the idle speed of the engine. Something to do with the way it helps exhaust scavenging.
OK, so what adjustments can we make that control the idle speed of the motor? Two things:
1. The idle speed adjustment screw (for a *hot* engine)
2. The fast idle wax unit (for a cold engine)
Technically, you need to adjust *both* of these. The idle speed adjustment screw you will use to set the idle speed for a hot engine, the fast idle wax unit may need adjustment to assist the idle speed for a cold engine.
Can you tell me what year your bike is? My 2002 needed no adjustment of the fast idle wax unit when I installed block off plates, but the 2006 motor (and ECU) didn't like the PAIR plates much unless I also tweaked the fast idle wax unit adjustment to raise the cold idle.
Don't think you're going to find too many loud straight pipes enthusiasts here to bounce ideas off. But I've been wrong plenty before ...
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[image: View Post]kaldek, on 18 June 2012 - 06:53 PM, said:
Can you tell me what year your bike is? My 2002 needed no adjustment of the fast idle wax unit when I installed block off plates, but the 2006 motor (and ECU) didn't like the PAIR plates much unless I also tweaked the fast idle wax unit adjustment to raise the cold idle.
It is a 2004. I didn't know there are separate cold and hot idle adjustment. Well tomorrow morning I'll find out if the fast idle was unit need adjustment or not.
[image: View Post]2thdr, on 18 June 2012 - 06:53 PM, said:
Don't think you're going to find too many loud straight pipes enthusiasts here to bounce ideas off. But I've been wrong plenty before ...
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To be honest I didn't like how loud the straight pipe is. However right now my daily commute is 30 miles lane splitting through the heart of Los Angeles. Need every bit of help to stay alive.
Soon I'll be moving closer to work so the stock pipe will go back on.
If you do need to adjust the cold idle, bear in mind it's a 6mm nut and you only need to adjust it a very small amount.
I'll throw my two cents in on the Popping issues. My prior Bike an 04 Yamaha Roadstar 1700 was stock. But then I wanted more noise. So being the cheap person I am, drilled out the exhaust making it basically a straight pipe exhaust. I got loads of popping on decel after that. Came to find out it was also equipped with a pair system that when throttle is closed on decel it pumps air into the exhaust right off the exhaust valve the causes unburned fuel to ignite, making the aforementioned popping. It’s the same on the VFR. Removing the pair system got rid of the popping. On stock bikes the exhaust has so many expansion chambers and silencers that the popping is not noticed or is barely audible.
Fueling also has an input on the popping as well when you modify the air flow the fuel needs to be adjusted as well. More air = more fuel, less air = less fuel.
I’m assuming if you’re running a sort pipe or straight pip right off the CAT you would also be running a PCIII or PCV – AKA fuelling may be part of the issues. Your map may need some more tuning this would also help with surging & choppy throttle response.
Sorry for the long post
This morning I fired up the bike and it idled perfectly around 1300rpm. Viola! No need to mess with the fast idle wax unit.
Now after riding it at median speed (~30-40mph) for ~45 minutes I have to say the popping on decel is definitely gone.
Thanks everyone for the help.
How long did it take you to install the plates? The only thing I don't like about my new leo vince exhaust is the popping on decel, I have done this mod on other bikes and has done the trick.
Thanks
[image: View Post]wshtb, on 19 June 2012 - 12:57 PM, said:
This morning I fired up the bike and it idled perfectly around 1300rpm. Viola! No need to mess with the fast idle wax unit.
Sure, but how cold was it this morning? Just be ready to maybe revisit this when the weather drops to below zero.