Why do I have a loud bang and fire coming from my Harley exhaust after a high rev?
I have a 2004 Night Train with a Wimmer spike air intake and the Supertrapp Phantom 2 into 1 pipe (no baffles of course). I had a Power Commander installed and tuned with my old pipes that were similar. It seems the new pipe backfires more often and way louder. Is there a leak? Am I burning too rich or too lean? Can I use the manual adjustment on my Power Commander to fix this problem?
it is fuel injected.
If you have popping on deceleration after wide open throttle, you can increase the mixture in the zero throttle position cells. I did that to my old Roadking which had a similar problem and it cured it. It was a few years ago, so I don’t remember the exact proceedure, but it was really easy. If you go to hdforums.com, you will find the instructions there.
I had the PCIII USB and it was a really incredibly nice piece of gear. It’s funny that someone ripped on it. I am thinking they probably never had one. It really opened up the possibility of tuning your bike youself, and if you don’t like the results, it is extremely easy to just go back to the previous settings you saved ahead of time.
One thing to consider is putting the baffels back and see if it cures the problem. I’m not familiar with your specific pipe, but I have never had any luck tuning a bike with a wide open exhaust like that.
Good luck man!
Plug that PC into a lap-top and see what you can do.
sounds like slightly lean to me
sounds like you’re too rich.
Power Commander? ….LOL!
You should have gotten a real Harley….They don’t have a Power Commander.
Newer bikes are tricky, since they are fuel injected. I added a stage one kit to my bike, which included exhaust, K&N filter, Ram Air Box, and Remap the computer. I’ve noticed that even little changes will effect the bike and results in unwanted behavior. People have changed their pipes and end up with back fires. Even if they are pretty similar to the original. I’ve heard that adding a fuel management system works only if it has already been remapped correctly. In other words, your bike is thinking that it’s still running with the old pipes, but the power commander is trying to compensate. It would be better to get it remapped and then use the power commander.
too much gas in engine lower it a bit and ride on t will save gas if you lower it too
a back fire is excess fuel exploding in the exhaust system, changing your fuel octane levels can make that difference! so try either premium or standard fuel and see if it makes any difference.
a higher compression motor uses higher octane fuel and just slightly less fuel to air as a lower compression motor that runs a richer fuel to air ratio, so standard fuel would be my choice.
and if the problem persists see it’s doctor!
you’re running rich,the real question here is why are you twisting your wrist so much ?
The loud bang is the combustion of raw fuel in the exhaust pipe. While this is often an indication of a rich condition, I am sure that the lack of back pressure in the Trapp pipes is causing an over-scavenging condition. It will show up on the dyno printout as a series of jagged up-and-down spikes between 2000 and 3000 RPM.
If you use a manual adjustment on the Commander to lean it up some, you might be doing more harm than good. A dyno printout will show what the air/fuel ratio is across the entire RPM range, and will indicate how the maps for your injectors should be modified. Obviously, you need to be near Stoich (14.7) across the entire RPM range, but a little rich from 4500-6000 is always better than too lean.
I’d have it dyno tuned by a professional that knows how to modify the maps for the fuel injection.