Lower MPG after 8k miles. Anyone else experience this?


linkgt

linkgt

Member
Before 8k, my mpg was always pretty good (40-45mpg range) and the first fuel trip bar would go down at around 30-33 miles, and the reserve wouldn't kick in till after 150-160 miles.

Right after I reached 8k, my mileage has started to suck! I've tried multiple gas stations to see if that was the problem, and they all yield about the same results. Today, I was on reserve(flashed at 110 miles -_-), tank took 3.6 gallons. When I got to the gas station I had 120 miles on it, so.. 120/3.6= 33mpg. It's been like this for over a month now.

I changed the spark plugs to NGK iridium, did oil change to 10w-40(since it's cold now), K&N oil filter, K&N air filter and this hasn't helped and recently I changed to a +1 front sprocket and that hasn't helped either in the mpg department. Also today, i was pretty soft on the throttle. Not as easy on it as I could've been... but easier than usual. I usually ride pretty aggressive, but when I got home the first Fuel trip bar went down after 20 miles... again, regardless of going smoother on the throttle.

Has anyone else experienced this? I'm thinking of buying SeaFoam or some type of fuel additive to see if it helps. Any suggestions on why this has happened? Is it just usual engine wear? I mean all summer long I did ride the bike pretty aggressive and at high speeds. I'm afraid maybe I have put a lot of wear on the engine :(. It has been colder and more windy since October. Can the cold climate have this much of an effect on mpg? Any input would be appreciated. Thanks
 
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stevet

New Member
How dirty is your K&N air filter? They need to be cleaned and oiled regularly unlike the Yamaha filter. I don't see why your fuel mileage would change drastically unless you were flogging your bike.
 
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MikeN02

New Member
Check your tire pressure? With the season change more towards winter the air will be lower than normal.
 
linkgt

linkgt

Member
stevet said:
How dirty is your K&N air filter? They need to be cleaned and oiled regularly unlike the Yamaha filter. I don't see why your fuel mileage would change drastically unless you were flogging your bike.
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Forgot to add, Since i've installed the K&N air filter, i've only put on 200 miles so I dont think it's that :/

MikeN02 said:
Check your tire pressure? With the season change more towards winter the air will be lower than normal.
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Also forgot to add that I do check tire pressure every week. I'm always on top of that and you're right. I've noticed pressure drops faster in the cold now.

It's just weird how i went from going to about 150 miles then reserved kicked in to about 110 miles to reserve to kick in. :(
 
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djf18374

New Member
linkgt said:
Forgot to add, Since i've installed the K&N air filter, i've only put on 200 miles so I dont think it's that :/



Also forgot to add that I do check tire pressure every week. I'm always on top of that and you're right. I've noticed pressure drops faster in the cold now.

It's just weird how i went from going to about 150 miles then reserved kicked in to about 110 miles to reserve to kick in. :(
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Did you just recently do the +1 tooth up front? That will correct your speedo/odometer, and it accurately shows your miles traveled. Your MPG calculated will drop by about 6% from before the swap but will be accurate vs. stock gearing which is "optimistic" at best.

To your point though, 33 MPG is not exactly great....if your tires are to spec'd pressure and the air filter is clean with good fuel, only your throttle hand and driving style (city vs. highway) can really make the difference.

Any other input on this? I'm not finding a great solution for it?
 
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Sparkxx1

New Member
I've been having this problem since after 1.5k miles.

Should I try sea foam? Maybe I should sync the throttle bodies too? Or could it be the fuel pump. I wanna say it might have something to do with the fuel pump but honestly I have no clue. Can anybody turn on their bike and put their ear to the tank. I've been noticing a really annoying "whine" coming from in there. I don't ever remember hearing it before, besides when I first flip the key on.

A couple of other people have also reported low gas mileage but nobody has figured anything out.
 
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flyingminno

New Member
Syncing the throttle bodies helps dramatically, at least for me. I too average about 160 miles before the reserve, then after a smooth freeway ride I averaged 120 before fuel bar flashed so I did sync the throttle bodies and changed the oil, then I re averaged 170 the next ride.
 
linkgt

linkgt

Member
djf18374 said:
Did you just recently do the +1 tooth up front? That will correct your speedo/odometer, and it accurately shows your miles traveled. Your MPG calculated will drop by about 6% from before the swap but will be accurate vs. stock gearing which is "optimistic" at best.

To your point though, 33 MPG is not exactly great....if your tires are to spec'd pressure and the air filter is clean with good fuel, only your throttle hand and driving style (city vs. highway) can really make the difference.

Any other input on this? I'm not finding a great solution for it?
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I did the +1 recently but mpg was hurting even before then. Yea No matter how I ride, mpg stays the same. I did about 40+miles yesterday and today and I was really easy on the throttle both days and fuel bar is indicating the same fuel consumption.

flyingminno said:
Syncing the throttle bodies helps dramatically, at least for me. I too average about 160 miles before the reserve, then after a smooth freeway ride I averaged 120 before fuel bar flashed so I did sync the throttle bodies and changed the oil, then I re averaged 170 the next ride.
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Ok, this has to be it then because I've done the basic tune-up such as oil change, air filter and plugs and even +1 tooth and no change. Plus, there are no leaks, no weird sounds, nothing out of the ordinary that is visible anyway. Now it's time to buy a synch gauge...

Thanks a lot for the help guys. I really appreciate it :thumbup: I'm not sure when I will get the chance to synch throttle bodies, but when I do, I will come back and post if it fixed Mpg or not.
 
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MiltonDorkenhoff

Search, THEN post.
Elite Member
linkgt said:
I did the +1 recently but mpg was hurting even before then. Yea No matter how I ride, mpg stays the same. I did about 40+miles yesterday and today and I was really easy on the throttle both days and fuel bar is indicating the same fuel consumption.
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Are the bars really that accurate a measure of anything? I mostly ignore them. I put gas in, I ride 125-150 or so miles (or until the F-trip comes on), I fill up and reset the trip meter. The gauge/bars are good for getting a rough idea of how much gas you have (i.e. "almost empty"), but beyond that I've found it to be useless.

My wife's bike (Triumph Bonneville) has no gauge at all. She has a stupid blue light. When she needs gas, it comes on. When she almost needs gas and leans into a turn, or heads up a hill, or stops too quickly, it comes on. We've learned to ignore the light and just get gas after 100 or so miles when we go for long rides :)
 
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dart1963

Super Moderator
Elite Member
linkgt said:
I changed the spark plugs to NGK iridium
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did you check the gap?

throttle bodies should not have a significant play in fuel mileage... it only sets how they sit at idle... unless you are in stop-n-go traffic all the time, in which case, you're going to get horrid mpg anyways.
 
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Deanohh

New Member
MiltonDorkenhoff said:
Are the bars really that accurate a measure of anything? I mostly ignore them. I put gas in, I ride 125-150 or so miles (or until the F-trip comes on), I fill up and reset the trip meter. The gauge/bars are good for getting a rough idea of how much gas you have (i.e. "almost empty"), but beyond that I've found it to be useless.

My wife's bike (Triumph Bonneville) has no gauge at all. She has a stupid blue light. When she needs gas, it comes on. When she almost needs gas and leans into a turn, or heads up a hill, or stops too quickly, it comes on. We've learned to ignore the light and just get gas after 100 or so miles when we go for long rides :)
Click to expand...
It also depends on how full you fill it. On side stand, center stand, sitting on it , etc.
And each time is it filled to the btm of the inlet pipe, touching, just below, just above?

As to why a mileage drop if everything else is constant? It seems like someone in this forum might have solved it before. But if not, maybe there is a Yamaha shop that could do a diagnostic on it.
 
linkgt

linkgt

Member
MiltonDorkenhoff said:
Are the bars really that accurate a measure of anything? I mostly ignore them. I put gas in, I ride 125-150 or so miles (or until the F-trip comes on), I fill up and reset the trip meter. The gauge/bars are good for getting a rough idea of how much gas you have (i.e. "almost empty"), but beyond that I've found it to be useless.

My wife's bike (Triumph Bonneville) has no gauge at all. She has a stupid blue light. When she needs gas, it comes on. When she almost needs gas and leans into a turn, or heads up a hill, or stops too quickly, it comes on. We've learned to ignore the light and just get gas after 100 or so miles when we go for long rides :)
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I know it's not the best method to go by, but when I reach 110, F-Trip is already flashing :/

dart1963 said:
did you check the gap?

throttle bodies should not have a significant play in fuel mileage... it only sets how they sit at idle... unless you are in stop-n-go traffic all the time, in which case, you're going to get horrid mpg anyways.
Click to expand...
You're not supposed Gap the Iridium plugs. As for the throttle bodies, that's what I would think but one user so far has said that it worked, so I went ahead and ordered a Gauge, should come by next week.

Deanohh said:
It also depends on how full you fill it. On side stand, center stand, sitting on it , etc.
And each time is it filled to the btm of the inlet pipe, touching, just below, just above?

As to why a mileage drop if everything else is constant? It seems like someone in this forum might have solved it before. But if not, maybe there is a Yamaha shop that could do a diagnostic on it.
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I've always filled it on the side of the side stand at the gas pump. I fill it just above the inlet pipe, always have since I got the bike.

Sparkxx1 said:
Whoa bad gas mileage.. - Page 3 - Yamaha FZ6 Forums - International FZ6 Motorcycle Community Forum

Try a battery reset. Seems to have worked to some extent for these guys...I'll give it a go tonight. =\
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Wow that sounds exactly like my story. Funny because my buddies FZ6 is getting worse mileage too at this point. I will try D/C the battery tomorrow and see if that helps.
 
linkgt

linkgt

Member
Sparkxx1 said:
I had forgotten I'm going to go disconnect it overnight.
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Definitely come back to post results. Going back to that Fz6 thread, the last thing NewOrleans mentioned was that he was starting to see improvement after her synched throttle bodies, then he stopped posting,disappeared and never posted a final result. Maybe we can take that as a sign that the synch worked for him as well and he just moved on from that issue.
 
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Sparkxx1

New Member
linkgt said:
Definitely come back to post results. Going back to that Fz6 thread, the last thing NewOrleans mentioned was that he was starting to see improvement after her synched throttle bodies, then he stopped posting,disappeared and never posted a final result. Maybe we can take that as a sign that the synch worked for him as well and he just moved on from that issue.
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Looking in my service manual now.

http://www.600cc.org/forum/f91/how-sync-throttle-bodies-fz6r-15991/

That's way easier. I'm ordering the tool after this week.
 
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