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Discussion Starter #1
I just bought a 2011 Custom, which has V&H slash cuts. All my previous bikes have been carbureted and I know switching pipes from stock usually led to mixture issues and re-jets.

I have no experience of fuel injected bikes, so just wondered if there were any issues switching pipes on those?
What if any adjustments may be needed?

It did ride pretty well, though I noticed a slight backfire sometimes on decel from highway speed.

Thanks
 

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If the bike has the stock air cleaner setup then you should be fine. If you have an aftermarket setup with the aftermarket pipes then you will need a tuner. Such as the power commander, cobra powerpro. Theres some auto tuners where you weld oxygen sensor bungs on the exhaust and install o2 sensors to adjust the fuel on the fly. Currently I'm running the cobra proflow air intake, cobra dragster exhaust and a power commander 5 tuner with a map downloaded from the power commander website.

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I'm with "jimmy74" on that if the stock air box (no mods) is still on the bike you should be good to go.
To help with the popping on decel, try blocking off the air to the reed valve near the ex-pipe, in the head.
Just do a search on (marbling). It helped with popping on mine.
 

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I have a set of cobra pipes and a cobra intake. Installed the power commander 5 with auto tune i like it takes the guess work out of it all. But the bikes are lean from the factory and any mods to the intake and or exaust will lean the bike further. Why take a chance. I have read a lot of people not doing anything else when putting pipes on with stock everything else and they seem to be ok.
 

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Discussion Starter #6 (Edited)
I picked up the bike at the weekend, it does have an aftermarket air filter in addition to the V&H pipes
It has a round Arlen Ness Big Sucker intake

For all I know it may already have the fuel/air management module too...is there an easy way to tell without pulling the tank off?
 

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Pop the seat off. A power commander will be mounted on the back side of the battery box. Its about the size of a pack of cigarettes

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It did ride pretty well, though I noticed a slight backfire sometimes on decel from highway speed.
Again, to make it clear, what you hear is not backfiring, never has been, never will be. What you hear is closed throttle popping in the exhaust on decel with the clutch out. The momentum of the bike on decel is "pushing" the engine to breathe more than it can with a closed throttle. To check this for certain, next time you hear the popping, pull in the clutch and the popping stops instantly.

All modern bikes that meet emissions standards pop on clutch out/closed throttle decel. It is totally harmless to the bike, just noise. The cycle makers dampen out the popping with large canister mufflers, to contain the popping. Aftermarket pipes/mufflers (usually because of their smaller volume and easier breathing), actually lean out the fuel/air mix more and increases the popping, which the aftermarket exhaust cannot dampen effectively and the popping gets worse. Some solutions foe the popping on decel:
1. Richen up the idle circuit fuel/air ratio. On a carbbed bike that means altering the idle jet and air mixture screw, possibly raise the needle. On a fuel injected bike the only choice is to alter the fuel to air mapping in the controller.
2. Go to a larger muffler system to dampen out the popping while still inside the muffler.
3. Pull in the clutch when on decel
4. Or simply live with the popping, as it does no harm to the engine in any way.
 
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