| Author | Message | ||
     Spottyd |
My 2004 XB12S is misfiring between 2500 and 3000 RPMs with no load...accelerates fine through that range. 15000 miles on the odometer and equipped with factory race kit (air filter, ECM, and race can). Idles fine and revs to the limiter under load. Any ideas? | ||
| Natexlh1000 |
If it's fine under load, I vote leave it alone. That's an awkward thing for an engine, running with no load. I wouldn't be surprised if it was just a lean spot and the behavior was just normal. My X1 behaves in a similar way and always has. I don't think my 2008 XB12X does though. I will have to try it. | ||
| M1combat |
Battery or Stator? Don't know why but that's my hunch. What do you run in the primary? | ||
| M1combat |
I seem to remember mine doing that at some point and I replaced the VR, Fuel Pump, etc... I think it was Stator, battery or bad intake seals. It was a long time ago though. If you replace the intake seals get the new ones with metal in them. They're awesome. | ||
| Spacecapsule1 |
my 12 does the same at slight load. always has. it drives me insane. i've replaced lots of parts...(spark plugs and wires, TPS, intake gaskets, Temp senor, O2 sensor, VR, Stator, stock and EBR ECM's) but its still the same. feels like its pinging or something. then does it again 3-4.5k at 1/2 3/4 throttle. i think the only way to correct the issue is to custom tune your ECM (fuel and timing). Curious what you mean by no load. do you mean just maintenance throttle or maybe slightly accelerating? Those 2 conditions are when mine does the same thing. Or do you mean you're in neutral and holding those rpms? | ||
| Spottyd |
Thanks to everyone for your responses. By no load I mean not accelerating or decelerating but maintaining speed in a given gear. The problem never appeared until 500 miles ago. I've ridden the bike since 2500 miles on the odometer (it's just north of 15k right now). I replaced the sparkplugs today and nothing improved. It pulls like a freight train to redline but still acts silly between 2500 and 3000 RPMs with steady throttle. | ||
| Natexlh1000 |
Oh. I thought you meant with the bike in neutral. My bikes all run fine at at that engine speed, maintaining speed on the road. I would suggest a TPS reset with a hot engine if you haven't already tried. | ||
| Fast1075 |
My 2004 lightning does it. It did it stock, It does it with a race ECM and a GB exhaust. The reason is the fuel maps are lean at small throttle openings with light load. I'm light enough to lug it up a gear to smooth it out. It helps to let it warm up a while before riding it most days, and you will most likely notice it runs smoother on a hot day. In any case it is the nature of the beast with a stock fuel and timing map. | ||
| M1combat |
I thought about it more. I seem to recall that replacing the intake seals helped for a while but it came back. I then took about .015-.020" off each side of the intake manifold and that solved the problem. Essentially the manifold was resting against the head and allowing a small intake leak after the seals were well used. I took my manifold off one day for some reason or another and a friend of mine pointed out that there was a witness mark where the manifold was touching the head. | ||
| Natexlh1000 |
That's an interesting observation. I wonder how common that is? I wonder if it happens in sportster manifolds too? | ||
| Greg_e |
Hylomar Though I did check mine for play when I was putting it back together yesterday because I was worried about the same thing. | ||
| M1combat |
"Hylomar" ??? | ||
| Spottyd |
I rode it in 40 Deg. weather yesterday morning after I cleaned the IAT bulb in the airbox with some electronics spray cleaner (at the end of last season I over-oiled my K&N filter so the inside of the airbox was a red oily mess). The bucking at steady throttle was worse than ever, Today I'll test the IAT sensor as per the manual. . | ||
| Brother_in_buells |
+1 for what M1combat say,s about removing some material off each side. i also have done that with an intake manifold from a 2004 xb12s and the popping was over when accelerating. | ||
| Dallasb |
My xb9 did the same thing at the ~2500 rpm mark. Did some custom tuning using tunerpro which fixed 95% of the problems in the fueling. If I recall correctly, there was a lot of fuel that I had to add to the 2500-3500 cells. Do a custom tune, which if you want the best running bike it should be done any ways, and see if that helps your problem. | ||
| Zaxrex |
My 2005 12S has always misfired slightly under light load. Especially during cold-start enrichment. It annoys the piss out of me. It will occasionally misfire between 2000 and 3000 RPM. Above 3000, it generally doesn't misfire or I don't feel it... | ||
| Blaylock1988 |
Just FYI, the ECM has a built in function that leans the engine while under heavy acceleration, which results in the dead spot that a lot of people see at around 3000RPM. They did this for noise regulations. There is a way to turn it off but it isn't easy... I don't know if the factory race ECM has it though. | ||
| Firemanjim |
"Just FYI, the ECM has a built in function that leans the engine while under heavy acceleration, which results in the dead spot that a lot of people see at around 3000RPM". Really,never seen this show ib any of the Buells I have tuned. Just finished an 08 this morning and no pulling of fuel at 3000rpm was seen. Now 2900 rpm has some of the "Learned Fuel" areas at 16,20,24% throttle, and those areasare going to be 14.5-15.1 as designed.But you will never see this area under heavy acceleration. | ||
| Blaylock1988 |
My mistake, it retards ignition timing, but it still causes the flat spot. It is described in the EcmSpy Tuning Guide V2 in section 5.4: http://www.ecmspy.com/tgv2/guide2.shtml#5.4 | ||
| Greg_e |
Hylomar is a gasket sealer. It also says that the 3000 rpm dead spot is only supposed to affect EU bikes, I have not tested this on my USA bike. | ||
| Blake |
My understanding is that the flat spot around 3K rpm is just a consequence of the exhaust system configuration. As with any exhaust, it has its stronger and its weaker spots in the operational rev-range. | ||
| Blake |
Blaylock, What the ECM Spy manual is talking about in Section 5.4... is the rev limiter, and separately the active muffler control (AMC). It doesn't say anything about ignition timing being retarded for noise, only that the AMC both aids performance and reduces noise. | ||
| Blaylock1988 |
5.3 (active muffler control) and 5.4 (spark advance retardation configuration) are unrelated ECM functions.
It doesn't make sense if it were the rev limiter because you don't hit the limiter at 3000RPM which is one of the areas that this affects. I don't see anything that specifies EU or USA. The guide says its for all XB models/makes. I apologize for getting so off topic. | ||
| Xoptimizedrsx |
what Blake said... I find timing a little high at that rpm. I have fixed many from doing it with a little reduction in timing. Remember these are OEM passable ecms so they must burn clean and in order to burn clean they need heat. to get heat sometimes timing is advanced to where its hot but not a real loss in power happens... This goes on in all companies. retarding can fix the issues and in many cases it will give you a slight bump in Tq with no HP change or very little. | ||
| Trafford |
My bike is running great!.....however it took a while to get to the bottom of the jerky running. its a 2006 EU XB12R I have owned it since 2008. My throttle idle position is 4.2%. I am in the Netherlands which means having to ride at 30mph or less a lot of the time, plus running at very steady almost closed throttle. In fact when I data-logged I was often running between 4.5-8% which surprised me. If you look at the standard fuel maps you can see there are very low figures in the bottom rows of fuel cells. For a long time I worked with other parts of the maps. But after data-logging I increased the ranges 4% 6% 8% from 0-2900rpm. I changed some timing values and took away 'Idle timing adjust'. Now the bike is behaving as I would expect. Smooth tractable and can easily run down to just under 2000rpm in top on a whiff of throttle. A world away from the standard map...which according to the Bike shop who registered the bike for me in Holland the owner said to me .... - this thing is un-rideable why on earth did you buy one of those...... Before anyone says it....I have perfectly sealed intake manifolds. (Message edited by trafford on April 15, 2012) | ||
| Spottyd |
Problem solved! New intake seals (James not crappy OEM)! Thanks to everybody for their suggestions. |
