| Author | Message | ||
     Hughlysses |
I've lamented on here a couple of times about the hit in gas mileage I found when I installed an 09 engine, ECM and wiring harness in my 07 Uly when the original engine had to be replaced due to a bad crank. Mileage dropped from typical 48-50 MPG to 42-45 MPG with the "new" engine under the same conditions. The last few tankfuls seem to be getting towards the lower end of that range, with 41 MPG on a fill-up today. I always run premium fuel (93 RON here). I've found that running non-ethanol fuel (at an increased price of 10-25 cents/gallon) makes NO difference. I've run as many as 3 or 4 tanks of non-ethanol premium in a row with no measurable improvement in fuel mileage. The O2 sensor on the bike is original and now has something over 45,000 miles on it. It's a fairly cheap part (~$25-$40 IIRC). Anyone think a fresh O2 sensor might improve my mileage? Of course the next question is can it be changed without rotating the engine? I haven't looked yet, but I seem to recall it's possible. Your thoughts? | ||
| Rayycc1 |
This is my first fuel injection bike...but i do no they go bad and can play havoc with the mileage on a car. For what its worth...I've only owned my Uly a month and a half ...put over 1k miles on it now and have yet to get as good as 42mpg...Plugs look like its running perfect.???  And mines only got 10k on it | ||
| Satori |
The oxygen sensor is just part of the equation. Its job is to know how much oxygen is leaving the engine, so it knows how to adjust the fuel trim. So can a bad one have this effect, yes. But as Ron Popiel would say but wait! there's more! You also have a measurement coming into the engine, which I believe in the case here is a IAT sensor. If its not reading correctly that could be a cause also. But Wait there's more! if there is a air leak in between the two, where air is entering without being measured, the OX sensor will think the engine is running lean, and add fuel.. That leak could be a vacuum leak, or around a throttle body any where in between the two sensors. The way to find that air leak is to "smoke" the engine, which is basically filling it with smoke, until the leak shows itself. See you tube for instructions and building an inexpensive smoke maker. A classic sign of a "engine lean" caused by any of the above will be a bit of a misfire at idle, which can be hard to sense, but also a slight stumble off the line, and not quite as much pull as it should have. Hope this helps. | ||
| Advoutlander |
I have the same issue. I replaced the 02 sensor and no change. I reckon my mpg dropped due to switching to tkc80 tires. | ||
| Natexlh1000 |
My 2008 has always had low 40's economy numbers when it's ridden in the same manner as my X1 that gets low 50's. They did something to the mix when they went to DDFI#3. Everyone was talking about it when the 2008 and 2009 bikes were new. My uly runs smoother and is taller/wider than my X1 so a reduced economy is expected. But there was more to it than that as you just discovered with your engine swap. TL;DR version: I don't think anything is wrong with your bike. | ||
| Reepicheep |
Did you change if you have the hard luggage on it or not? That can make a big difference also. | ||
| Hughlysses |
I recall the drop in fuel mileage when the 08's came out. The early ones were VERY poor but this was improved with updates to the ECM maps so I didn't expect this big a drop with the 09 engine and ECM. I have no complaints about the bike's performance; it pulls harder than it did with the 07 engine. Bill- I generally run with the topbox only. I have seen north of 50 MPG with all 3 bags in place riding 2-up on more than one occasion with the original engine. I'm getting 42-44 MPG now with only the tailbox riding by myself. I think the best mileage I've gotten since the engine swap was somewhere around 48 MPG in the mountains of NC. I've always been surprised at the mileage improvement at altitude, even while railing the twisties all day. Of course the original engine would do ~52 MPG under the same conditions. I'm thinking about getting the ECM programming updated which will change the fan logic. Since that might get me a later fuel map, it'll be interesting to see if that changes the mileage at all. | ||
| Ourdee |
My mileage on the 08 improved with a race ECM. It never did as good as the pre-08 bikes. I squeezed 50 out of it riding slow in the winter, but usually got around 44 mpg. I always thought a map for mpg could be produced at the expense of the controllable power curve. There has to be a fuel efficient spike that was programmed out (my opinion). A program to let you toggle that 50 to 100 rpm into proper trim for mpg would be a neat trick. I would like to know what the dyno guy at EBR has to say. | ||
| Electraglider_1997 |
Hugh, I changed out the O2 sensor on my 06' ULY and you do not have to rotate the engine. You'll need a 7/8" crowsfoot socket once you get at it to remove it. Approach it like you would to change out the fan. Once you rotate the fan and get it out of the way then the O2 sensor is right there in front of you to remove. That O2 sensor can be bought at Autozone or any other auto parts store for $20. Of course you can get it at American Sportbike for twice or more that amount. My O2 sensor was giving off code 13 at around 35K miles. I've read where they begin to decay after 15K miles so yours is well past it's prime. If you do remove it make sure you use anti-seize to install the new one and the Permatex is safe for O2 sensors, says so right on the container. | ||
| Hughlysses |
Craig- thanks for the info. Of course removing the fan is a bitch of a job so I'll have to get pretty motivated to do it. In Al's defense he's just charging list for the OEM part. For some reason OEM oxygen sensors seem to be 2 or 3X the cost of the sometimes-identical universal parts. I bought a universal one for a Volvo 940T a couple of years ago; OEM part was $100; universal was $20. I did have to cut off the old plug and solder onto the new one, which took all of 5 minutes. | ||
| Mark_weiss |
MPG (at least on my '08) seems to be very strongly influenced by altitude. The DDFI III seems to burn more fuel than earlier bikes when ridden at low altitude and less fuel at higher altitude. I'm working in Albuquerque this week and noticed that on the ride over from Phoenix I averaged over 56 mpg. That's about 10 mpg higher than I normally see with similar types of riding in Arizona's lowlands. I'll see what effect the extra 3500 feet has on daily riding. The commute here looks to be pretty similar to home. | ||
| Ratbuell |
it pulls harder than it did with the 07 engine. And to do that, it needs fuel. Commonly noted change, as it was stated above, when they changed to the 08 engine and DDFI3. | ||
| 1313 |
The early ones were VERY poor but this was improved with updates to the ECM maps I keep waiting for somebody to put 2 and 2 together on this and come up with the real answer. There may have been an adjustment to the fuel maps, but that's not the major contributor to the crappy fuel economy numbers reported by the early DDFI3 XB's... Until someone nails it I'll be the one giggling in my helmet, 1313 | ||
| Hughlysses |
^ Bad odometer calibration? Hmmm. Maybe I should check mine... | ||
| Ratbuell |
Lemme guess...they changed injector suppliers and the flow rates were WAAAY off... | ||
| 1313 |
^ Bad odometer calibration? Close, VERY close... Take it one step further and you should have the answer (to why the early DDFI3 XB's seemed to have significantly lower MPG's than DDFI2 XB's). Please do not confuse this for what it is not. This is NOT the reason that someone would see lower fuel economy over time/after a period of time. Wouldn't you try to make as much as you could as accurate as you could if you came out with a new version of anything? 1313 | ||
| Uly_man |
A drop of 2 to 3 mpg is very little and can be caused by many things IE Tire pressures, dirty air filter, etc. Anyway this sort of mpg is ONLY and average measurement over an unspecific period. I would not worry much unless it drops to 30 - 35 ish in which case you would have a problem. | ||
| Froggy |
Hugh, there is likely nothing wrong with the bike. For reasons beyond my explanation, the DDFI3 system consumes a little more fuel than DDFI2. Changing the O2 won't hurt, but I doubt it will improve things for you. I see similar discrepancy between my 06 and 08. | ||
| Hughlysses |
Ran a tank of gas out today. It included one ~55 mile round trip commuting to work (50% streets/50% interstate) and ~105 miles of mostly cruising backroads at 60-65 MPH. Got 46.5 MPG on this one; much more like normal. I guess my commute is just not conducive to good mileage. The interstate backs up at least 2 or 3 times a week leading to ~5-10 miles of stop and go traffic. I imagine that's got a lot to do with it. | ||
| Rayycc1 |
I'm trying to understand this Data logging thing for ECMspy....do you have to have a wide and o2 sensor to do it? and are they available? | ||
| Sagehawk |
Im going to get set up to do data logging on my uly in the next month or so. Be a learning curve for several of us. Ill share what i learn, right things and wrong things as well. When wife and i did a new orleans trip several years ago, her 96 sporster sport pulled in at 52 mpg for most of trip. Highway mileage is much higher than the commuting mileage. 10 or 12 mpg difference. Just saying. | ||
| Uly_man |
"do you have to have a wide and o2 sensor to do it?" The O2 sensor on the bike is all you need. Do not worry on a wide band type as that is another story and not the type fitted to the bike. | ||
| Rayycc1 |
I thought i had read somewhere that it would take in and use information faster with a wide band sensor,...and I'm sure they were talking about this bike...i have no idea if its available or where to get it though...like i said ...just trying to wrap my head around it | ||
| Uly_man |
http://en.wikipedia.org/wiki/Oxygen_sensor Go here to read up on them. | ||
| Nobuell |
My 08XT has been having a rough idle issue when cold but would idle fine once warmed up. It also seemed to run OK once warm as well. In an effort to eliminate the idle issue, I replaced the intake seals, IAC, head temperature sensor, air temperature sensor to no avail. I also swapped the EBR ECM for the stock unit with no change. Last week I broke down and removed the under seat pan and comfort kit plenum to replace the O2 sensor. Not a hard job but a PITA type of project. After replacing, the idle seemed a little better after a short ride. I assumed the ECM had to learn new fuel ratios. So, yesterday I went on the Slimy Crud run in Wisconsin. As miles were added, the bike started running progressively better. Now the idle issue is resolved and more importantly, the bike is running better than I can remember. Over the past year the bike seemed to be down on power and did not seem to rev as freely. Also it seemed to be lacking in the mid range. I always assumed that the bike was OK based on comparison to my 1125R track bike. I just assumed the Uly was OK because the track bike is much faster. Perhaps the O2 sensor degradation was slow making the bike run progressively worse but not very noticeable due the change rate. Anyway, it is like riding a new motor cycle (albeit one with 46K miles). I did not check the fuel mileage on this trip because we were running pretty hard. Historically, I would get approximately 45 MPG. I could push towards 50 MPG if I rode very conservatively. This bike never achieved 50 to 55 MPG like some have reported with older years. Moral of the story, if you have higher miles, it may be worth replacing. It is a bit of a pain but could be $18.00 dollars well spent. | ||
| Electraglider_1997 |
And just like I wrote above and Nobuell mentions, you do not need to rotate the engine like I believe the Service Manual dictates to change the O2 sensor. You just need to remove the comfort kit underseat shroud and then the fan screws and then rotate the fan to get it out of the way to get to the O2 sensor. Seems like the mono shock needed to be moved out of the way also but that was the least of the job as I remember. 7/8" crowsfoot to unscrew the sensor. | ||
| Motorbike |
Nobuell, thanks for the post, good info. What O2 sensor did you use? H-D or aftermarket? I'm guessing at $18 it was an aftermarket (we all know you cannot buy anything at an H-D shop for less than $20). Can you please provide the Brand, Part Number and Place purchased? Thanks! | ||
| Nobuell |
Once you remove the fan, the sensor can be removed using an o2 sensor crows foot tool. I used a Bosch Premium Oxygen Sensor Part No. 12014. Fit perfectly. | ||
| Nobuell |
The o2 sensory was in stock at autozone and advance auto. Also, the upper shock mount must be removed and pivot the shock out of the way. | ||
| Whisperstealth |
Damn on having to move the shock out of the way. I'll be doing this soon, and have a bit of phobia about messing with the shock. But REALLY good that the engine doesn't need to be rotated. |
