FJR fuel milage

[john8698]

Hi everyone. Just thought I would check with you guys on something. I ride an 05 FJR with 70,000 on it. Until about a month age I was getting 46 mpg. Not I'm getting 39 mpg. Bike runs great. New plugs and air filter about 5000 miles ago. Tires good. 36psi front and 40 psi rear. Do not run the bike hard. Any suggestions

 

[zed88]

Where do you live? Fuel composition may have changed in your area. They have been screwing with all kinda of stuff. 10% ethanol?

 

[john8698]

I thought about that too but I have lived here in NW Arkansas for almost 3 years and almpst always buy 89 octane from Wal Mart.

 

[DJB]

Try running some good fuel injection cleaner through the system. May be just some bad gas. Also look to see if your brakes are binding. Did you change your boots? If so you may be riding your back brake. Happened to a friend of mine once. He wore the back brake down to nothing. Check you r rear shaft change fluid in the differential. When was the last time you did a sync on the fuel injection. I had to replace mine at about the same milage. If you run the bike on the highway at the same speed all the time you may have worn the butterflies in the throttle bodies. Does the bie surge at all or ever feel like it is lagging behind at certain speeds.

 

[kolonial72]

I had a sudden, brief fit of low fuel economy a few months back. Found out the rear brake lever was binding. Cleaned and lubed the pivot, now my mileage is back to where it should be.

Anyone know if the 36 psig in the front tire may result in lower-than-ideal fuel economy?

 

[john8698]

Try running some good fuel injection cleaner through the system. May be just some bad gas. Also look to see if your brakes are binding. Did you change your boots? If so you may be riding your back brake. Happened to a friend of mine once. He wore the back brake down to nothing. Check you r rear shaft change fluid in the differential. When was the last time you did a sync on the fuel injection. I had to replace mine at about the same milage. If you run the bike on the highway at the same speed all the time you may have worn the butterflies in the throttle bodies. Does the bie surge at all or ever feel like it is lagging behind at certain speeds.

I sync the injection system last year. I might need to check the back brakes. I have had problems with them binding in the past.

 

[RossKean]

A couple of weeks ago, I decided to remove the PC III that was on the bike when I bought it (used) over a year ago. I noticed a SLIGHT change in low throttle behavior - a little jerky if I wasn't careful. I am quickly getting used to it. Little or no difference at speed. I may try the G2 throttle tube and/or Grip Puppies to help me smooth things out. The biggest difference was an overnight average improvement of 20% in fuel mileage (measured by calculation at fill-up)! Just thinking about the money I didn't need to spend on gas over the last 30,000 miles! I know that there are mapping choices that can be made to make the Power Commander a little more fuel friendly but I don't see any reason why I would consider putting it back on the bike. The previous owner had the bike Dyno tuned with the PC III and I suspect that ultimate HP and smoothness were high in his list of priorities as opposed to reasonable economy.

I was "playing around" with riding styles today and checking/resetting the average mpg meter to see what the sweet spot was for mileage. I did a ~50 mile run (more like a walk) down a back road and actually kept to the speed limit (50 mph). I was careful to avoid anything more than very mild acceleration and was very conscious about using brakes as little as possible. I did the return trip on another more-or-less parallel route but did not worry about rate of acceleration and probably averaged close to 70 mph.

The difference in mileage was remarkable. On the Harley-paced ride, the average mpg monitor said 55.5. On the FJR-paced return trip, it read 40.2. This probably isn't news to most of you but I was quite surprised. I realize that the Avg. MPG display might not be exact but it should serve as a reasonable basis of comparison between two legs of a ride.

Ross

 

[03HiYoSilver]

John,

Have you checked your Air Filter? A clogged filter will give you bad mileage.

Good Luck with your fix...

 

[john8698]

John,

Have you checked your Air Filter? A clogged filter will give you bad mileage.

Good Luck with your fix...

Sure have. Put a new one in less than a year age and checked it the other day. Looks like new. Just filled up today and the thing is back up to 48 mpg. Go figure....

 

[HotRodZilla]

If that's the case, I'm betting bad gas.

 

[FJRBluesman]

39 is not bad, not sure how you got 46 all the time. Less than freeway miles may do that. On the back roads I get high mileage too, on the freeway to work about 40 on average.

Make sure all things are still the same, no jack rabbit starts, riding like fairlaner, etc.

 

[john8698]

39 is not bad, not sure how you got 46 all the time. Less than freeway miles may do that. On the back roads I get high mileage too, on the freeway to work about 40 on average.

Make sure all things are still the same, no jack rabbit starts, riding like fairlaner, etc.

I have been doing more interstate lately.

 

[FJRBluesman]

39 is not bad, not sure how you got 46 all the time. Less than freeway miles may do that. On the back roads I get high mileage too, on the freeway to work about 40 on average.

Make sure all things are still the same, no jack rabbit starts, riding like fairlaner, etc.

I have been doing more interstate lately.

Interesting. You'd think steady throttle at X speed would be best, like interstate riding. When I'm on back roads, I modulate the throttle huge. I would guess that due to my throttle control I'd get poor mileage, just the opposite occurs. I get my best mileage on back roads messing around than on the freeway at a constant speed. Granted I'm going more slower than freeway speed, but my throttle modulation varies greatly. But that slower speed really helps rather than spinning higher steady RPMs.
Make sure youre comparing apples to apples on your mileage, same driving each day, like to work for a tank or five and compare those results. I've gotten as bad as 34mpg and as good as 56mpg (that one shocked me), I thought maybe high 40s at best.

Good luck let us know how it goes.