I had all my worldly problems solved with the help of Courtney @ Durango Harley Davidson in Durango Colorado. It cost me $400.00 to get it figured out but it’s much better now. To make a short story long, it was basically a fuel mixture problem with my Power Commander PC-V controller and Auto-Tuner combination. Some of you guys having a similar problem with your bike making a lot of clacking noises and having PC-V Auto Tuners might want to read this long winded saga.

My 2012 FLHX was not running right. It would make a lot of what sounded like either valve train slop, timing chain or primary chain noise when I was just getting started with the engine cold and just slowly putting out of my neighborhood. When in 1st or 2nd gear at around 3000 rpm and I backed off just a little on the throttle I would get what I thought was lifter clattering or something in the valve train making noise. Then after it was warmed up and I honked on it hard, I’d get up to above ~ 4000+ rpm with 80-100% throttle and the bike would start knocking LOUD. I was convinced that something was wrong internally and wanted to get the bike into an authorized dealer before I ran out of warranty.

I wanted Slade, the Durango Harley shop manager to ride it himself and diagnose it. Slade is really good and knows his stuff, but he normally doesn’t work on the weekends. So when a guy named Courtney called me on Saturday morning after he rode it and told me his diagnosis I thought he was full of ...you know what. Boy was I wrong.

Courtney said that as soon as he rolled across the dealership parking lot at idle that it was pinging from detonation and pre-ignition. He said it was the same problem under high speed high torque situations. I do admit that the high end noise It was so loud on my bike that I thought it was going to blow something out a cylinder or case. He basically said that all my problems were being caused by my PC-V tuner and auto-tune combo and that I should just get that system off of the bike and get a Screaming Eagle Race Tuner (SERT) installed or go back to stock. I figured he didn’t know what he was talking about and that he was just pushing the Harley product. I also figured that he was just listening to the exhaust note and not the valve train or primary engine noises that I was hearing. This Power Commander package ran me about $800.00 for just the parts, so I wasn’t too thrilled about his suggestion. He also said that he was familiar with the piggy-back method of the PC-V but not really familiar with the exact nuances of how the system worked or what it was capable of. Not a good answer to me and I wanted to basically kill the messenger.

I unceremoniously told Courtney to just put it out front of the shop and I’d come pick it up later on that same day, Basically writing the DHD shop off from my list forever. When I showed up to get the bike, I wanted to talk a little with Courtney but the ‘moat dragon’ running the front desk said “He’s too busy right now to talk to you.” Now I was really pissed, but I just paid my bill and left without saying anything. In my mind never to return for any work again.

I did some running around town with the bike but needed to kill some more time until my wife came up from Farmington, NM to meet me. So I ended up going back to the dealership and hanging out on the sales floor and cooling my jets in the back area for a while. As I sat drinking some free coffee, one of the parts guys came around the corner saying that Courtney was looking for me. I wasn’t sure what to expect from him but I went back to the shop with some apprehension. Courtney is a BIG dude! But he was really cool. He was very patient, polite and talked to me at great length. It was time for the shop to close up but he stood around and talked to me for a long time, even while his wife was standing there waiting for him to go home with her.

I explained as much as I knew about the PC-V/Auto Tune system and he listened to me intently as I rambled on. I asked if he had specifically listened to the internal noises the engine was making and that he was sure there were no lifter, valve train, primary or compensator issues going on within the engine. He reassured me that the internal workings were good and that the noises were coming from a badly tuned bike. I finally asked him if he would like to have me bring in my laptop and hook the bike up to the self testing software of the Auto-Tune program. He seemed interested to learn about the tuner and so I brought out the dog and pony show. He seemed to be impressed with how the system worked and how much it could do and wanted to know more. I offered up that if he would like to learn more I would bring the bike back after his days off and I would offer up my ride as a Guinea -pig for both of us to learn how to deal with the tuner. He said that would be great and on Tuesday morning I was there at opening time for more investigating.

Courtney put my bike on the dyno and started to run some tests. We wanted to see if the numbers from the auto tune tables and oxygen sensors were what we were actually getting out of the exhaust. It turned out that as soon as the bike was started the Air Fuel Ratio (AFR) was very lean at about 16.3.to 1. This didn’t make sense to us because the power commander was programmed to run much richer than the stock settings and we were expecting to see numbers around 13.7 to 1

Just some background info... From my days as a flight and maintenance instructor.... Hopefully I got this right:
The world standard for what is known as a ‘stoichiometric’ mixture for gasoline is considered to be a ratio of 14.7 to 1. This means 14.7 units of air to one unit of fuel. At this ratio you should achieve a complete controlled burning of the fuel. If it’s richer than this number (smaller number like 11.0 to1) then you will have excess fuel unburned that will go out of the exhaust. This can cause several bad things like, black smoke out the exhaust pipe, smelly exhaust, fouling of your plugs with black carbon, excessive deposits of carbon in your cylinder assembly and occasionally a phenomena known as ‘after-firing’ (When the excess fuel that did not burn is ignited in the exhaust pipe causing a loud bang or pop. Often mistakenly referred to as a backfire but it’s actually an after-fire, since it happens past the flow through the cylinder.) If you have too lean a mixture (higher number like 17.0 to1) the fuel can explode in the cylinder, causing excessive pressures in the cylinder and possibly damaging components, overheating and possibly a true ‘backfire'. (Which is where the fuel charge blows back into the intake system and can belch flame out of the air filter.) Just for clarification, true back-fires and after-fires are usually more associated with incorrect ignition or valve timing. Naturally if the mixture is way too rich or lean the fuel will just not ignite at all. A lot of engines will be set to run cooler by enriching the mixture to more like 13.2 to 1 to allow the unburned fuel to carry away excess heat from the engine.

I have to mention here that I put a set of Vance Hines Power Duals and a Arlen Ness big sucker intake on my bike in addition to the PC-V/Auto-Tune.

After a lot of holding for and talking on the phone to the Power Commander tech support people, we learned a few very important points that we did not know. The most important one being that if the mixture reading detected by the auto-tuner are above 16.0 to 1 (too lean) or below 11.0 to 1 (too rich) the auto-tuner just refuses to accept the numbers and will not try to correct it. I just considers it corrupt data and will not mess with it. Thus no changes or auto tuning will happen in that range. This is what was happening to my fuel charge at the low power settings and what I thought was valve slap or lifters was detonation...not good!

I believe what caused this initial super lean number was me installing the better breathing exhaust and intake. Those improvements caused so much more air to flow into the cylinders that the stock fuel injector charge was too low (lean) and getting the AFR up around 16+. If you look at your low end numbers on a basic PC-V download you will see that most of the maps don’t do any mods at idle or at 2% throttle.

We were able to improve the numbers on the low end range by forcing the power commander to initially start up with more fuel being shot into the injectors to bring the range closer to 13.0 to 1. We did this by increasing the fuel setting to a +30 on all 2% power settings and rpm. Then once the auto tune took over (Which is 60 seconds after starting. Another important number to know.) it will recognize a number that is in the ballpark that it can work with. After that realization and correction everything fell in place and the bike ran very smooth and quiet (No perceived/supposed valve train noise) on the low end power settings.

The upper end noise racket was settled down by enriching the target AFR to about 12.7 to 1 for throttle positions of 80% and higher and greater than 4500 rpm. This helped the gawd awful high end detonation but did not eliminate it. Which lead us to discover something else that is a good to know item. The auto-tune function will not automatically adjust timing. It has the ability to let you manually advance/retard the timing but it will not do it automatically. I did not know this! We ended up retarding the timing on the high end settings to stop the pinging and got a nice quiet power blast at high torque and rpm settings. I still need to play with this a little to get it perfect.

My sincere apology to Courtney at Durango Harley for me being short with him. He was 110% right on his diagnosis and he really went out of his way to get my bike running great. He didn’t have to do this but he took the extra time to learn the new stuff with the Power Commander. Courtney has literally done thousands of tunes with the Harley SERT but now also has a good handle on the PC-V Auto-tuner stuff. I highly recommend you guys stopping by there and asking for him if you end up in the area and need some work done. Actually all the techs are pretty damn good there. DHD phone= 970-259-0773 ext 5

Hope these little tid bits help some of you guys working with the PC-V and Auto-Tune.

Ride safe.

 

thats awesome.... and rare