Hi all,
I have a 12R, it has 23,000 miles on it and Ive had a few issues over the couple years I've had it. This post is unforntunately not about my bike. It's about my brother's 12R. He has a 2004 with 4,600 original miles. Its absolutely beautiful. The only issue is at under 3000 rpm he has a nasty sputter, cough, stutter, i don't know what to call it. So i suggested he do a crank breather reroute.
We tore into his bike this morning and somebody started it but it was missing a few things. We did it right and it still isn't running any better. It has irridium plugs, the air box has been drilled, and the exhaust has been modded.
I don't have a way to check the ecm to check the map, but until it arrives, is there anything else to check? Anyone have a suggested map besides the race map for his set up?
Thanks,
Please don't mess with the ECM and mapping until you fix the bike.
I assume by "when it arrives" you mean a cable or dongle? First thing to check is the AFV and see what the ECM is trying to do. You can do a TPS re-set just because, but report back what you find...
Cooter,
What exactly is the AFV doing? I've read a bit but I'm still not really clear. I should get the dongle next week and hopefully I'll be able to ride down to my brothers place before the week of Christmas.
I'm glad you told me to check the AFV first because I just assumed it was a bad map.
The AFV is Adjusted Fuel Value. It's a fudge factor built into the system that allows the ECU to easily make changes to the air/fuel ratio based on a variety of different factors that the computer processes, including the input air temperature, head temperature, and the detected mix by the O2 sensor on the exhaust after it finishes a cycle. This value, though a tiny bit crude, is the single most important tool we have to determine what the mix inside the cylinder is doing.Originally Posted by Javalin
The AFV is intended to be set at 100.
When the AFV increases, it means that there is a lean condition and the ECU is compensating by adding more fuel to the mix. This is because the cylinders are either getting too much air (leaking air intake seals are a common problem on this bike), or the fueling system is not delivering enough fuel (I'm going to bet that this is a problem for you based on the age of the bike and low miles). If your AFV is under 110-115, I wouldn't worry too much. I'm betting heavily that your AFV will probably be in the 140+ range, which means there is a serious (though very, very solvable) problem.
When the AFV decreases, it means that there is a rich condition and the ECU is compensating by pumping less fuel to the mix. I've never had to deal with this, so others will have to chime in on what's happening.
An important thing to know is that there is only one O2 sensor on your bike. It is by the rear cylinder. If you pull the plugs and there's a ton of soot on one plug and not the other, then you'll need to look at spark plugs, ignition coil, ignition coil wires, and fuel injectors (the only parts that are not shared by both cylinders). Also different between the two cylinders are the head temp sensor (only on rear head, not both).
Now you'll notice earlier that I said I'm betting on a fuel system problem. This is because I dealt with nearly exactly the same issue that you're describing. 09 XB12scg, 2400 miles at purchase this year. AFV was 143, intake seals showed no leaks, and it would sputter/backfire under 3k rpm, die at idle, and start very rough. The problem with old bikes and ethanol fuel is the ethanol breaks down over time and gums everything up when they sit. Run a fuel pressure test and you'll probably find low fuel pressure (you'll need to order a Fuel Pressure Gauge Adapter which is specific to these bikes - Lance from St. Paul Harley is an excellent resource, though they're backordered 3 week right now). If the fuel pressure is low, then you'll need to replace the fuel pump/regulator/filter/tube. The fuel tube sometimes breaks when it's old and needs to be replaced. It's kind of a pain to do (you really should remove the rear swingarm to complete this maintenance), but the repair itself isn't expensive. http://a.co/8eUl8wl, http://a.co/bdvdTIl, https://www.mcmaster.com/#9464K543 Are all the parts you'll need to complete the entire repair. If not, then more than likely you have clogged fuel injector(s) and/or fuel rail. You can send these out to be cleaned for like $30.
You'll probably want to change the intake seals while you're in there to be honest. The throttle body is right where the injectors are, so you're really only one step away from improving something that could have used improvement in the first place (James Gaskets are what I recommend).
Let me know what you find!
Last edited by gdisaac07; 12-07-2017 at 03:03 PM.
Good advise ^^^^
Fuel maps don't "go bad". Use the dongle and ECMDroid to re-set the TPS just because its free and easyPost what the AFV is and lets go from there.
Same issue on my 07, AFV for mine is at 120.5. Thinking my o2 sensor is bad. Got the buelltooth dongle in the mail last night. Best investment I have made....
The O2 sensor is tough to change, and you need a crowfoot wrench and 6” or 10” socket extension. Make sure you’re using anti-seize as well. Don’t be surprised if your O2 sensor is working fine though. If there is a change in AFV, then it indicates that the sensor is properly communicating a problem with air/fuel mix and the ECU is adjusting. If the sensor is verified, then you should look at the list of things I put down in my first reply to this post.
Good Luck!!
Javalin,
I just went through this same thing on my 2008 XB12R. It had a intake cough, sputter, etc. I replaced plugs, cleaned throttle body, used sea foam, tps resets, etc, etc. I finally fixed the problem (permanently) by replacing the intake seals. It took me about 5 hours from start to finish. Apparently, these bikes are notorious for leaking intake seals. You can test your existing seals by simply spraying carb cleaner in the area around the seal while the bike is running. If the rpms change when you spray the carb cleaner, you have found your ptoblem.
You can purchase a new set of seals from your local Harley dealer. They are common on sportsters so most dealers have them in stock. Once you put the new seals in, you will have to perform a tps reset. Bike will run rough for about 10 miles or so. After that, she’ll run like a champ. Trust me on this one and you’ll save yourself a whole lot of time and aggravation.
PM me if you need help.
Anthony
Also check intake leakage after replacing intake seals. If replacing intake seals does not eliminate leakage you will likely need to consider another seals https://www.twinmotorcycles.nl/artik...?cid=7&aid=452
Or maybe the stock intake flanges are bad? it I heard happened one time. You should PM TPEHAK for a free set sent to your door. He loves to help fellow Buellers
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