I just finished installing V&H slipons with SE AC along with V&H fuelpak management system on an '07 Sporty. The bike sounds and runs great, but there is a lot of popping on decel. Sometimes, I will get single pop when letting off on the gas when shifting gears. V&H swears that the settings they gave me are correct. I checked the settings several times and also looked for exhaust leaks. I know popping is usually a sign of a lean mixture, butI'm not seeing any other symptoms. Is this normal? Any ideas?

 

I would be looking at the chance of an exhaust leak again. Did you reuse the gaskets or buy new ones?

 

I'm sure I'll get roasted for this but you can have popping on DECELLfrom a rich condition. I just got my bike off the dyno and the only time I had ANY popping on decell (complete with flames) waswhen my AFR dropped below 12.5 under load.

When you get off the gas you close the throttle valve which means virtuallyno air is going into the motor. Any fuelwillcause a rich condition to the point it won't burn until it gets more oxygen which can be sucked infrom the exhaustpipe (vacuum is extremely high in the cylinder when the RPMs are up,throttle is closed and no ignition occurred.Bring in some fresh air and pop). Exhaust leak at the head pipe would be a prime suspect along withopen pipes.

Don't believe me. Next time you run hard andget off the gas hold the throttle open a little which will allowmoreair in to lean out the mixtureand see what happens.

 

Well put cjuetten.

"So let it be written, so let it be said".

[sm=icon_cheers.gif]

 

CJ is right on the money,I have spent alot of time experimenting with settings on my SG with PC III USB,I have been able to dial it in to get no popping at all,when settings were rich I would'nt get much decel popping but on and off the throttle bangs.

 

Can I get one of those pops.. I would like to make sure it is running sometimes when I let off of it and I want others to know I am around....

 

I also agree with cj, no roast from me.During decel a misfire caused by being too lean or rich will cause unburned fuel to exit into the exhaust pipes where oxygen causes combustion, leaks or no leaks. On my bike I have it programmed for no fuel during decel until it decels down to 1600 RPM, never any pops, but I'm not sure you can do this with other ECMs and software. This is done on today'scars and trucks, called deceleration fuel cut off (DFCO). Some will argue that allowing fuel during decel helps to cool the engine,it does,but I question how much and if it's needed.

 

I have Vance and Hines Big Shot with a Stage 1 and ran there fuel pak as well and had popping on decel all the time. I changed to a PClll got it dyno tuned and all of the popping is gone. I talked to the Vance and Hines service people many times and tried to adjust the fuel pak per there recommendations but none of them worked. The best thing to do is get the PClll and you will have no more popping.