| Author | Message | ||
     Chadhargis |
I'm new to the Buell family, and I'm enjoying my bike a great deal. I do, however, have a question about the fan and how the ECU controls it. My Ulysses has 5000 miles on it, and I switched to synthetic oil at 3000 miles. Normally, once the bike gets warmed up, the fan comes on and never goes off. It keeps wailing away. When I shut the bike off, the fan runs fast for about 30 seconds, then drops to a lower speed before shutting off. Today, I was on a ride and I never heard my fan running. I was pushing the bike fairly hard, and no fan. Bike ran perfectly. No pinging, no check engine light, or other issues. In fact, it felt "peppier", if that makes any sense. I finally stopped to check it out only because it deviated from the norm. When I shut my bike off, the fan was running, but very slowly. Then it shut off. I took a more crowded road on the way home so I could get in some slow moving traffic. When I got home and shut the bike off, the fan was running slowly again, then after about 10 seconds, it shut off. I pushed the bike into the garage, and took my helmet and gloves off. All the sudden, the fan kicked on and sounded "normal". It ran for a couple of minutes and stopped. The bike doesn't feel overly hot. It's running better than it ever has. Seems to have plenty of power and absoultely won't ping even when I grab a handfull in a high gear. So...how does the fan work? Anyone know the logic the ECU contains for the fan. Is my fan kaput, or is my bike now fully broken in and running cooler? | ||
| Davo |
The fan has a few parameters: Key on- fan on 428 F Key on- fan off 356 F Key off- fan on 338 F Key off- fan off 302 F The ET sensor is in rear (#2) head. The ET goes directly to the ECM and it triggers the operation. The parameters are very simple. The logic is very debatable. I agree with the logic that Buell has excepted. The rear head needs that fan running most of the time to keep clean air across the plug base of the head. The left side scoop pulls air in while the bike is moving directly on the rear head. The right side scoop captures preheated air around the fuel injection system components. When the bike is moving fresh air comes in the narrow right side scoop to cool the front head and the pre-heated air then keeps the injectors in a clean burn zone. The fan does pull some air through this narrow scoop when the bike is not moving. The fan is also instrumental in keeping the flange area of the rear header cool. A stock bike even in cool weather will have the fan run almost continually after it starts even at highway speeds. If your fan does not come on after you run the bike for about 20 minutes then I would be guarded and would listen for it eagerly. If you ride on dusty roads you might check to see that the fan moves freely. Synthetic oil may delay the fan operation for several minutes. Of course other xber's will chime in with testimonials of rare fan operation. My only explanation is that there must be enhanced coiling parameters on the xb12x. The fan does work especially when in traffic. There is also a skip spark mode as a back up cooling system programed into the ECM Check all of your grounds and battery cables for a good connection. A 12 volt DC negative ground system is very intolerant of poor connections! I hope this editorial helps. | ||
| Lost_in_ohio |
I was wondering the same thing. IMHO there seems to be little rhyme or reason as to why it runs. I read the same thing in the operators manual. So does anyone have opinions about adding a right side air scoop to match the left side?????????? I would think that it should help. | ||
| Jlnance |
FWIW, I went on a long ride last week and was supprised at how little my fan ran. I actually checked to see if it was broken the next time I stopped, and it seemed to ok. It was a cool morning and I was crusing on the interstate. Apparently this provided the engine sufficient air to cool the head w/o using the fan. | ||
| Chadhargis |
Even when new the fan seemed to have two speeds. A high and a low speed. Anyone know how the high and low speeds work? What temps does it switch from high to low? | ||
| Jlnance |
does anyone have opinions about adding a right side air scoop to match the left side?????????? I would think that it should help. Oh there is another thread where this is debated to death.  According to the people who have tried, it makes the fan run less, so it clearly helps fan noise. Does it help the engine run cooler? Perhaps. Here is what I can tell you. If your fan is cycling on and off, the head temp is between 356 and 428F regardless of whether the scoop is there or not. So if your fan runs continusouly w/o the scoop and intermittantly w/ the scoop, then the engine is cooler. If it runs intermittantly both with and w/o the scoop, then it's running at the same peak temp. If it doesn't run w/ the scoop, then the engine is running cooler. Something that hasn't been addressed is what the best temperature to run the engine is. It is certainly possible for an engine to be too cold. I have absolutely no idea what the optimal temperature to run an engine is. I would guess from the numbers above that it's about 390F. That would also explain why the key off numbers are lower. The engine doesn't benefit from being hot when it isn't running. | ||
| Lost_in_ohio |
that is a great question....what is the optimum operating temp. I guess I am used to water cooled engines where cooler is generally better. | ||
| Brucelee |
The right side scoop is the deal! | ||
| Honu |
I was under the impression that the fan is there to protect the integrity of the oil, not to cool the engine. Sportsters and other HD's don't use fans, any thoughts on this??? | ||
| Pwnzor |
Sportsters don't have the rear head buried within the frame! | ||
| Destroy |
Would putting on a RH air scoop void the warranty? | ||
| Chadhargis |
Hey, this IS post 9/11...no highjacking allowed! LOL!! Back to the topic... Does the fan indeed have two speeds? Is my fan kaput or is my bike simply breaking in? | ||
| Darthane |
XB fans (well, my year, at least, a 2003) do indeed have two speeds. Based on your descriptions, nothing sounds out of whack...when I switched to synthetics in my Firebolt the fan came on noticeably less often and for shorter durations as well. ...if you never hear it at all, then that's a problem.  If you're so inclined, you can check to make sure your CHT sensor is still functioning properly (I believe the service manual lists the resistance values of various temperatures), but that involves removing a good chunk of stuff for a little teeny bit of peace of mind. | ||
| Chadhargis |
I think my next step is going to be to get the bike good and hot, then hook it up to my laptop and read the temp. | ||
| Davo |
My garage arrival temps are with and without the right side cover plate were always between 397 F and 401 F. I tested it starting off as soon as the previous cool down stopped. I road the same loop and I pushed the bike each time. Other days arrival temps have been as low as 379 but never lower in warm weather. If you got a scoop you may be arriving at 420 and your fan has not come on yet. If you double the air going into the rear pocket you will need to open up something in the fan area to let it go through or you will just create drag. Enhancing the cooling system and actually having the engine run cooler are two different things entirely. There are other ways to cool of a combustion chamber with wider ranging benefits. | ||
| Bake |
Breathing funny voids warrenty around here! | ||
| Diablobrian |
warranty work is largely dependent on dealer discretion. | ||
| Tunes |
I have an '04 12s, fan is two speed, 7K miles. Modifications are: race kit... and I keep the bike tuned at all times... i.e. I obsess over the way it runs. My fan runs and doesn't run at some weird times... to me anyway. Most of the time, when it's hot out or the engine is run for extended periods (long day ride) the fan operates as usual. However, there are times when the fan doesn't come on... and when I shut the bike off, it runs on low for a few seconds. I always notice the operating temp is very consistent. The weather here in the Northeast changes constantly so we get the full monty treatment and the bike (and fan) handles it all. No complaints, the bike runs great. I'd keep an eye and ear to your bike. Notice everything. | ||
| Buckinfuell |
Three things I hate most about my XB12S: 1) Stock handlebars (they look like something off a child's tricycle) 2) Stock exhaust (that blatty sound like my Lawn-Boy lawn mower) 3) AND, that DAMN FAN NOISE!!! I fixed the first two, thanks to Crossroads and KD Fab, but I guess I'll have to live with the third  | ||
| Diablobrian |
After break-in, synthetic oil seems to reduce fan run time and frequency too. | ||
| Brucelee |
"I guess I'll have to live with the third" No you don't. Get the right side scoop. My fan last came on back on May 1 for about 3 minutes. Otherwise, life is good and quiet. Oh, use Red Line 20W-50 also. Good luck. | ||
| Chadhargis |
Anyone with an in at the factory have any input? I'd like to bend an engineers ear for awhile. Like I mentioned above, the bike runs fine, but the constant whine of the fan is not there. I'm a big proponent of the fan (a fan of the fan so to speak). It's a great idea, simple yet effective. I want my fan screaming like a banshee when I stop. It lets me know I've ridden the bike properly.  | ||
| Ferrolano |
Brucelee, So where/who has the right side air scoops for sale for our XB12's? I don't mind the fan noise at all--to me it's a comfort knowing it's working and helping to keep the rear cylinder/head from frying itself. On the other hand, anything I can do to improve the airflow to the rear cyl and keep it cooler I'm willing to do--provided it's a proven part, not just for looks. | ||
| Chadhargis |
Well, the verdict is in. My bike does seem to be running cooler than when it was newer. I set out tonight to get the fan to come on. It took about 20 minutes of high RPM riding, then sitting in traffic, but the fan did come on normally. So, I guess the end result is that my bike has broken in and loosened up a bit. |
