| Author | Message | ||
     Cirwin2010 |
I've had my 2006 Buell xb12ss for about a year now. Since having I have been experiencing a rattling sound when under hard acceleration. The noise is inconsistent, but seems to be more common at mid to high rpm in gears other than 1st. It also only seems to make an appearance when the bike is hot. The bike is equipped with a K&N air filter, Race ECM, and original Drummer exhaust. The AFV is reading 105.6% I have gone through the bike to try to eliminate anything that could be rattling. To try to rule out spark ping, I put some octane booster in the tank. This seems to have helped the issue. Now thinking that the issue is spark ping, I have change the spark plugs to see if that was the issue. I put some NGK DCPR9EIX iridium plugs in and had them gaped to 0.035 inches. Unfortunately this did not seem to make a change to the rattle I am hearing. Has anyone experienced anything like this? I am doing a track day in August and I don't want to damage the engine. The only things I have left that I could try are a more specific tune for the exhaust (I have a map that I have not flashed yet) or checking the static timing (which I prefer not to do since that requires some drilling). | ||
| Natexlh1000 |
Have you checked the horn mounting yet? Look for marks on the inside of the flyscreen from it buzzing up against it. | ||
| Cirwin2010 |
I did check behind the flyscreen. There used to be another rattle from that area. I put some rubber on the HID ballast and that fixed that issue. I didn't notice anything with the horn mount though. That rattle was clearly coming from the front and was present all the time. This one appears to be coming from below me, though it is hard to tell since the bike is loud. | ||
| 1_mike |
Ignition "ping" and spark plugs have little to do with each other..! Though sometimes, a colder spark plug can help. The ping or preignition normally comes from hot spots in the chamber (small pockets of fuel), and normally caused by a lean condition. All that said, with your K&N filter (more air in) and Drummer exhaust (more air out), it sounds like your "race" ECM is not keeping up with the new fuel requirements with these parts that have been added. Your addition of a fuel additive has proven that. So...what to do. Either remap the ECM (best choice) to richen the fuel in the lean locations or run a 100 (+) octane "Race Gas" (expensive !). I know when I modified the stock muffler on my XB12, my "race" ECM also...could not keep up with the new fuel requirement. I had to richen about 3/4's of the map to get it to run well, and have no detonation. Now, it's running great and getting 49/50mpg. You gotta realize, that more air in and out of the combustion chambers...NEEDS more fuel to keep the fuel ratio correct, as you've noted above. Mike | ||
| Cirwin2010 |
Thanks for the reply Mike. I'll have to try the Drummer specific map I received from Buelltooth. Hopefully that will help make a difference. I was under the impression that the race ecm ran rich. The bike smells when you get on the gas. Makes the whole road stink of exhaust. That paired with the popping I get on decel gave me that impression (I understand a lean mixture can do this too). Can other factors make the exhaust smell other than running rich? | ||
| Zacks |
Just another something to check. I had the front muffler strap break and caused a rattle as it vibrated against the can. Maybe not an issue with the Drummer but... | ||
| Tpehak |
As I understand you do not feel any significant power loss which should have place in case of preignition, so this is not spark plug or preignition issue. | ||
| Cirwin2010 |
There are two things I would like to add here that may be helpful. The rattle seems to be in sync with the rpm of the engine. Higher rpm - higher frequency rattle, lower rpm - lower frequency rattle. I sometimes experience what I can only describe as a backfire into the airbox. If I blip the throttle from a low rpm I sometimes get a pop that I hear and feel between my legs. | ||
| Cirwin2010 |
I put a new tune on the bike that was built specific for the Dummer exhaust. The rattle still occurs once the bike heats up. | ||
| Shoggin |
You never mentioned it, so I'm making sure you are using a good quality premium gas? I believe the NGK '9' plugs are one step colder, try running the hotter '8's You sure describe what seems to be lean pre-ignition. The fuel map can be rich (stinky) at idle and still lean up top. The only way to know is a wideband O2 and a dyno run. You'd never feel it with your butt dyno. Well worth a dyno tuning session at your local shop. Especially if you're going to track it. Pre-ignition can also be caused by carboned up valves or pistons. There are effective cleaning methods you can do at home, like the OG cold water trick  NEVER use an abrasive media internally on an assembled engine, I know someone who did that | ||
| Tpehak |
I cleaned valves on my Buell with walnut shell media blasting it in the intakes without disassembling engine. It is not abrasive actually, it is like hard wood, but it cleans really effective. Walnut shell blasting is actually standard maintenance procedure on BMW motors to remove crap from the valves. Aircraft remover soaking dissolves carbon really good too. (Message edited by Tpehak on June 07, 2019) | ||
| Cirwin2010 |
I am using 93 Octane gas at the pump per manufacture specifications. I am not sure if hotter plugs would do anything considering the problem occurs when the engine is proper hot. After some more riding I have found that I can replicate the noise pretty constantly with a hot engine. Putting the bike in second and giving a lot of gas as it passes through the 3000-4500 rpm range will definitely do it. If the engine is cool such as I have only been riding it for 15-20 minutes with little to no stopping to let the engine heat up, I cannot replicate the problem no matter how hard I try. There is a dyno at a shop about an hour away, but it can be expensive. I have some Seafoam. I did run some through one tank of gas already. I thought about the method of slowing pouring it in the throttle body while running but it seemed risky. Might be worth a go. | ||
| Skipbarberman |
If it doesn't load up, you might consider running a COLDER plug. Carbon results in pre-ignition or pinging when it gets warmer. Hot spots of carbon are igniting the mixture prior to the plug firing. In hot conditions/climates with these air cooled bikes - something worth considering. Do you have a borescope or access to someone with one to look at the combustion chamber? EDIT -.....said captian obvious, as he re-read the obove comments..... (Message edited by skipbarberman on June 07, 2019) | ||
| Tpehak |
Another things you can check: Not enough fuel pressure at high RPM - make sure the fuel pressure at hight RPM is withing limits according manual. If the fuel pump can not provide enough pressure and you rapidly open throttle the engine sucks more air and not enough fuel and more air with less fuel is more explosive and can cause pre ignition. You also can install permanent digital fuel pressure gauge to monitor possible fuel delivery issues. https://www.buellxb.com/forum/showthread.php?55083 -Buell-XB-fuel-pressure-gauge Clogged injector - clogged injector does not deliver enough fuel which again causes lean condition. Bad Throttle Position Sensor - if the sensor does not represent correct position of the intake valve the ECM does not put correct amount of fuel anymore so the fuel-air mixture is not correct and more explosive. The engine temperature might affect bad TPS too. Something is wrong with the intake manifold - like loose intake valve, loose or improperly installed intake rubber boot, leaking intake seals or anything else causing inconsistent air delivery. Bad intake valve seal and worn intake valve guide - it is likely exotic case, but the engine might suck extra air through the intake valve interface right from the engine case if the seal of the valve or the valve guide or the valve stem are badly worn or damaged. And also you see AFV only for the rear cylinder and it might be OK for the rear, but if the issue is in the front cylinder you will not see it in AFV. (Message edited by TPEHAK on June 08, 2019) | ||
| Cirwin2010 |
An update for what I have tried. Over the weekend I ran a bottle of Seafoam through the intake manifold to help eliminate the possibility of carbon buildup. After smoking up the neighborhood and going for a ride, there appears to have been no change to the issue. I have done a few TPS resets already. The latest being when I flashed a different fuel map to the ECM for my exhaust. I think my next step is checking the static timing and resetting it. I wonder if the timing is too advanced. The bike vibrates a lot so I would not be surprised if it slipped out of proper adjustment. @Tpehak How can I determine if there is a leak in the intake manifold without disassembling it? (Message edited by cirwin2010 on June 10, 2019) | ||
| Tpehak |
https://youtu.be/QewgdFjh23A | ||
| Cirwin2010 |
So carburetor cleaner should work for testing a leaking intake? | ||
| Tpehak |
Yes. Detach left and right air scoops, let the motor idle for 10 minutes and then spray on the intake seals in different spots. Any RPM change means there is a leakage. (Message edited by Tpehak on June 10, 2019) | ||
| Swanthog |
I had a similar issue on my '06 Uly. I discovered the rattle was coming from the Drummer muff internals (not inlet). I removed the Drummer and the rattle went away. Definitely a scary sound when you don't know what's going on. | ||
| Cirwin2010 |
Update: I am still waiting on the 3/8th hex to arrive in the mail so I can check the static timing. I downloaded and activated ECMSpy and got it connected to the bike. I discovered that the new map actually had failed to flash to the motorcycle. It still matches the race ecm map and not the Drummer exhaust map. I will have to try again later. How do you read the numbers on the ignition timing map? I know how to read the fuel map but not the ignition map. I am curious and trying to compare the two maps. Does a higher number mean more spark advance? | ||
| Cirwin2010 |
So I think I finally ruled out the issue. The static timing was ever so slightly advanced (flywheel marker was slightly left of top dead center). It was maybe two degrees off. I adjusted the static timing so the marker was centered and so far the bike is better behaved. The pinging has almost entirely gone away. I tried really hard to get the bike to ping again and I only got it to do it two or three times under very specific conditions. The bike had to be running for a while to fully heat up. Then I let the bike sit and idle until it reached about 240 degree Celsius. At this point I immediately gunned the throttle. The noise would come back but would just tick a few times then stop (probably after a little air flows through the engine). This behavior seems more normal to me. The only thing left to do is map the fueling again. | ||
| Natexlh1000 |
Nice! 2 little degrees. Have you noticed any performance changes? | ||
| Cirwin2010 |
Performance feels the same from what I can tell. When the bike pinged I didn't feel any power loss though, it just made that horrible sound. |
