MPG issue? 2008 FJR w/15k miles

[BLS]

So just last Thursday I purchased a very well maintained 2008 FJR with just under 15,000 miles on it.

Filled up on Saturday and rode it to work and back this week, with some minor in town riding. 70% of the time on it was backroads/hwy.

Got down to a 1/4 tank today so I filled it up again. Both times, same manner. Standard kickstand down, filled it up until I could see the gas up in the fill 'tube' (whatever you call it). It's enough to where you can't put in anymore gas without raising the pump up into that tube and it will then click off pretty quick. Regardless, you get the idea....trying to get a consistent amount of fuel in it, so I can accurately gauge my MPG.

Had 148 miles exactly on it when I pulled up to the pump. Put in almost exactly 4 gallons (4.065 to be exact).

MPG = 37 It seems awfully low.

I've never had the bike over 80 MPH and probably never over 6k RPM. I most certainly have not 'gotten on it' by any stretch. Sure, passing a car, etc, but I'm not a "rocket rider"; I just bought it for commuting.

I also noticed a few days after riding it, that down low, especially when starting from a dead stop, the throttle was 'raspy'. Like it wasn't running very smooth. Seems ok on the roads, but I have no frame of reference so I don't know what's good and what isn't.

But the response down low is not very crisp.

My assumption is they are related (MPG and throttle response).

Aside from the standard "change the plugs", is it possible I'm missing something else?

I keep running across stuff like "sync your throttle bodies" and "make sure your CO settings are correct"; neither of which I've done before.

I'm not mechanically challenged, but both are issues I don't want to go down unless someone says that's a likely cause (hope that makes sense).

 

[TomInPA]

I had some amazing MPG results recently. Mostly on higher altitude tours, I have been getting 47 to over 48 MPG, including several stints above 100 MPH and lots of passing. More to the point, I have often had mileage like yours around town. Until you can get out and let it run, I wouldn't worry too much about it. Any stop and go driving really hammers my fuel economy.

At 15K miles, if you don't know the service history, do an air filter and spark plug change, and consider running an injector cleaner through a tank or two of fuel.I'm actually a believer that it is a good thing to bounce off the rev-limiter sometimes. For me, I got greatly improved mileage by adding a windshield spoiler that allowed me to run at a lower height and more raked aerodynamic angle. How you load the bike with top-case and the size of your shield can have a surprising effect.

 

[radiummadman]

I had some amazing MPG results recently. Mostly on higher altitude tours, I have been getting 47 to over 48 MPG, including several stints above 100 MPH and lots of passing. More to the point, I have often had mileage like yours around town. Until you can get out and let it run, I wouldn't worry too much about it. Any stop and go driving really hammers my fuel economy.

At 15K miles, if you don't know the service history, do an air filter and spark plug change, and consider running an injector cleaner through a tank or two of fuel.I'm actually a believer that it is a good thing to bounce off the rev-limiter sometimes. For me, I got greatly improved mileage by adding a windshield spoiler that allowed me to run at a lower height and more raked aerodynamic angle. How you load the bike with top-case and the size of your shield can have a surprising effect.

Very good advice, see FJRtech for good info. on TBS, etc. . Seen other answers to mpg question & the one I liked best was something like "I didn't buy it for mpg, got it for twisting the

throttle" or I say SPG "smiles per gallon". If you were getting 42 mpg would you be happy ?? If so you would only be going 20 miles further on

that fill-up. As Bachman-Turner said "ride, ride, ride ...."

 

[carlson_mn]

Yamaha rates the bike at 38mpg to expect. I am also in the TC here so I am at same location and same type of ethanol gas. I average about 40mpg and I am on the gas quite a bit, however, I always get it into 5th gear as soon as possible. Play with the instant-mpg meters on the dash - mine is nearly spot on accurate after I calculate it at the pump. Do the simple things like air filter and plugs as they are probably both due. Bike gets about 44mpg on steady highway cruising.

We will never see the mpg numbers guys out west in the mountains get. We are nearly sea level (600-800 feet)

 

[BLS]

Yamaha rates the bike at 38mpg to expect. I am also in the TC here so I am at same location and same type of ethanol gas. I average about 40mpg and I am on the gas quite a bit, however, I always get it into 5th gear as soon as possible. Play with the instant-mpg meters on the dash - mine is nearly spot on accurate after I calculate it at the pump. Do the simple things like air filter and plugs as they are probably both due. Bike gets about 44mpg on steady highway cruising.

We will never see the mpg numbers guys out west in the mountains get. We are nearly sea level (600-800 feet)

Thanks Carlson. I've watched your videos on YouTube. Maybe we can meet up for a scoot sometime.

I'll throw the regular stuff in when I have time and report back.

I had some amazing MPG results recently. Mostly on higher altitude tours, I have been getting 47 to over 48 MPG, including several stints above 100 MPH and lots of passing. More to the point, I have often had mileage like yours around town. Until you can get out and let it run, I wouldn't worry too much about it. Any stop and go driving really hammers my fuel economy.

At 15K miles, if you don't know the service history, do an air filter and spark plug change, and consider running an injector cleaner through a tank or two of fuel.I'm actually a believer that it is a good thing to bounce off the rev-limiter sometimes. For me, I got greatly improved mileage by adding a windshield spoiler that allowed me to run at a lower height and more raked aerodynamic angle. How you load the bike with top-case and the size of your shield can have a surprising effect.

I'll do as suggested and replace the regulars and run a bottle through the tank. Any objections to sea foam?

 

[carlson_mn]

I'll do a throttle body sync with you for a case of beer too. PM me if you're interested sometime.

 

[03HiYoSilver]

Might want to do a Fuel System Treatment:

https://www.seafoamsales.com/gasoline-engine-faqs.html

 

[BLS]

I'll do a throttle body sync with you for a case of beer too. PM me if you're interested sometime.

That's VERY generous of you. You're on.

I teach handgun carry permit classes for MN/WI, so most of my weekends are booked, but I'll make a point to bring you a case of beer and learn some things as well.

I've noticed you like to ride around what appears to be the Welch area. I'm not in the same caliber of rider as you, but we should definately meet up.

 

[carlson_mn]

I'll do a throttle body sync with you for a case of beer too. PM me if you're interested sometime.

That's VERY generous of you. You're on.

I teach handgun carry permit classes for MN/WI, so most of my weekends are booked, but I'll make a point to bring you a case of beer and learn some things as well.

I've noticed you like to ride around what appears to be the Welch area. I'm not in the same caliber of rider as you, but we should definately meet up.

Sounds good - I'm gone riding for the next week in AR but we can meet up in June.

 

[SkooterG]

That mileage sounds low, but not all FJRs are created equal. Though most FJRs tend to average in the 41-47mpg range, you are not the first to report disappointing fuel mileage in the high 30s.

Why do some get worse mileage? Who knows. Other than aggressive riding habits (which doesn't sound like you), there are differences from bike to bike. My guess would be your fuel injection is running rich, or you have an issue with an injector(s), but that's just a guess. Are your brake calipers hanging up and not releasing fully?

I don't think plugs, a tbs, air filter, or fuel treatment is going to make a difference, but they sure can't hurt.

You might just have to live with a low mpg one.

 

[James Waszak]

All in all, you sound like your normal. Back up to the basics. you bought a 1300cc bike, that is built for performance. If you were looking for total economy a 250cc is the bike to get. Riding this bike to squeeze mpg's out of it will lead to dirty oil quickly, more maintenance cost i.e... fuel system cleaning, throttle body cleaning, spark plugs will fowl out faster, and more often. Plus its harder on an engine normally running easy, when you do get on it it wears harder. Basically I am saying, you are fine and your 16000mi service is almost due. that, if done properly by the book will solve any small tuning/agitating issues you may or may not have. I highly recommend a professional 16k mi service be performed! very important if you plan to make real miles on any bike. my last bike was an 85 Suzuki. still ran great at 195k mi. Just parts not available for that two year model.

 

[TomInPA]

Yamaha rates the bike at 38mpg to expect. I am also in the TC here so I am at same location and same type of ethanol gas. I average about 40mpg and I am on the gas quite a bit, however, I always get it into 5th gear as soon as possible. Play with the instant-mpg meters on the dash - mine is nearly spot on accurate after I calculate it at the pump. Do the simple things like air filter and plugs as they are probably both due. Bike gets about 44mpg on steady highway cruising.

We will never see the mpg numbers guys out west in the mountains get. We are nearly sea level (600-800 feet)

Thanks Carlson. I've watched your videos on YouTube. Maybe we can meet up for a scoot sometime.

I'll throw the regular stuff in when I have time and report back.

I had some amazing MPG results recently. Mostly on higher altitude tours, I have been getting 47 to over 48 MPG, including several stints above 100 MPH and lots of passing. More to the point, I have often had mileage like yours around town. Until you can get out and let it run, I wouldn't worry too much about it. Any stop and go driving really hammers my fuel economy.

At 15K miles, if you don't know the service history, do an air filter and spark plug change, and consider running an injector cleaner through a tank or two of fuel.I'm actually a believer that it is a good thing to bounce off the rev-limiter sometimes. For me, I got greatly improved mileage by adding a windshield spoiler that allowed me to run at a lower height and more raked aerodynamic angle. How you load the bike with top-case and the size of your shield can have a surprising effect.

I'll do as suggested and replace the regulars and run a bottle through the tank. Any objections to sea foam?

No objections at all. I have used it. It's not the miracle juice some people make it out to be, but it's a good maintenance precaution. Those of you in upper midwest get some pretty long lay-offs for the bikes, and cleaning things up once a year can't hurt.

 

[SkooterG]

All in all, you sound like your normal. Back up to the basics. you bought a 1300cc bike, that is built for performance. If you were looking for total economy a 250cc is the bike to get. Riding this bike to squeeze mpg's out of it will lead to dirty oil quickly, more maintenance cost i.e... fuel system cleaning, throttle body cleaning, spark plugs will fowl out faster, and more often. Plus its harder on an engine normally running easy, when you do get on it it wears harder. Basically I am saying, you are fine and your 16000mi service is almost due. that, if done properly by the book will solve any small tuning/agitating issues you may or may not have. I highly recommend a professional 16k mi service be performed! very important if you plan to make real miles on any bike. my last bike was an 85 Suzuki. still ran great at 195k mi. Just parts not available for that two year model.

I'm not sure I agree with any of that, but I guess that what an internet forum is for - a place for a variety of opinions.

 

[BLS]

That mileage sounds low, but not all FJRs are created equal. Though most FJRs tend to average in the 41-47mpg range, you are not the first to report disappointing fuel mileage in the high 30s.

Why do some get worse mileage? Who knows. Other than aggressive riding habits (which doesn't sound like you), there are differences from bike to bike. My guess would be your fuel injection is running rich, or you have an issue with an injector(s), but that's just a guess. Are your brake calipers hanging up and not releasing fully?

I don't think plugs, a tbs, air filter, or fuel treatment is going to make a difference, but they sure can't hurt.

You might just have to live with a low mpg one.

I noticed revving it up in the garage for a buddy that it smells rich. It certainly needs to be tuned, but it's not horrible either.

Any recommendations other than a dyno tune?

02 sensor?

 

[rfulcher]

My 07 gets between 36 and 39 mpg. The mileage was better before the big Rifle windshield and Power Commander III. I think the PC III is the major factor in decreased mpg. However the bike runs so much better with the PC III that it is worth the decreased mpg. Maybe you have a PC III?

 

[escapefjrtist]

I noticed revving it up in the garage for a buddy that it smells rich. It certainly needs to be tuned, but it's not horrible either.

Any recommendations other than a dyno tune?

02 sensor?

Have you lifted the seat and looked around the bike? If the PO installed a Power Commander you have your answer...

Check the O2 sensor wire. If it's unplugged that's another PC clue.

Good luck solving the mystery!

--G

 

[carlson_mn]

That mileage sounds low, but not all FJRs are created equal. Though most FJRs tend to average in the 41-47mpg range, you are not the first to report disappointing fuel mileage in the high 30s.

Why do some get worse mileage? Who knows. Other than aggressive riding habits (which doesn't sound like you), there are differences from bike to bike. My guess would be your fuel injection is running rich, or you have an issue with an injector(s), but that's just a guess. Are your brake calipers hanging up and not releasing fully?

I don't think plugs, a tbs, air filter, or fuel treatment is going to make a difference, but they sure can't hurt.

You might just have to live with a low mpg one.

I noticed revving it up in the garage for a buddy that it smells rich. It certainly needs to be tuned, but it's not horrible either.

Any recommendations other than a dyno tune?

02 sensor?

We will also do the Barbarian Mod and get into the diagnostics and see the CO levels. Stock level on all 08s is 10 on each cylinder. If it smells rich and you're getting 37mpg, we can try backing them off a bit and see if that makes a change. No need for a professional tune, all these bikes ask for is the occasional set of spark plugs and air filter. The TBS is just a nice thing to do, may slightly help fuel economy if it is off a ways. When I bought my 08 last year it had the original air filter and plugs in it still at 21k miles, had never had a sync and it ran perfect, - of course I changed them though.

If you discover it does have a Power Commander and the O2 sensor is unplugged - plug it back in. It's a misconception that it has to be unplugged. It will just revert back to 14.7 at idle and low throttle and steady cruising speeds, and you'll get your mpg's back.

 

[Chuck35]

I did The Barbarian mod on my 08 and it seems to get a couple more mpg. It took all of 10 minutes to do and the bike is a different animal!

All the low end stumble is gone. I have mine at 17 (+7) across the board.

 

[Aasland]

When I first read your MPG and low speed issues I thought "your intake cam is off a tooth" but with only 16k there would be no reason that it would have been off the bike yet - not until 26k. But what you're seeing is consistent with my experiences, with a PC3, VStream, low-quality fuel and cam off a tooth.

Even if your cam timing is right, with a windshield and PC3 that MPG isn't far out of line.

I know that, to some, this might sound like "take my wife out to dinner", but if you can let another FJR owner ride your bike they can verify if it feels "right". When I finally fixed my cam it felt like I had another 20 hp. Had I ridden any other FJR's that would have been obvious.

And stop peeing in the river - I have friends in Lake City who eat the fish from it