Seriously Bad Fuel Economy

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Welldunn

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I agree with the check your breaks idea. If its not that, I had a similar problem with my 04. It went from 190-200 miles per tank to around 160. After doing everything you have tried with no help I cleaned and recharged my K&N filter. I was back up to 190 miles on the next tank. It had been about 12 months since I last serviced the filter with lots of riding in the rain in between.

 

beemerdons

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I knew you cruising the COstco parking lits and calling it a ride would take its toll on the poor ole FeeJ.

I'm stumped brother. Let the wiz-bang-gurus help, like ionbeam, Fred W's, et al.

Good luck.
Brother Slappy, I've waited until dog pile Friday to give you the correct answer. You ride with johnny80s don't you? And you stop for lunch with johnny80s don't you?

johnny80s waited until you left the table, made a mold of your gas tank locking key, and is now regularly stealing your gas! Case is solved! Don't Ride With Dago's!!!

 
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Slappy

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Update,

I pulled the brakes and all is as it should be. Put the bike on the center stand and spun the wheels. There is a slight rub but that is normal.

As far as Ethanol is concerned that has already been accounted for. I use to get 240 and tank, but once ethanol came to Kali it instantly dropped to 220-210 depending on the station. This has been a constant drop in mileage over the last month or so. Tank after tank I slowly got less and less.

To all, yes I never disconnected the O2 sensor. I just put the power commander to treat a severe case of throttle snatch. I knew that the PC reduced fuel economy, I just wanted to get a base line of what the bike was really getting to see if I just had a glitch. Turns out I got worse mileage without it.

For all those that question octane. I have two Volkswagens 1.8L turbos. They require 91 octane. I have put high octane in those cars for the last 10 years. They take 13 gallons a fill up. At this point paying what I pay for gas, adding an additional 5.5 gallons a week is a drop in the bucket. Besides, every time I have pulled the plugs they have looked perfect. With the questionable gas I get down here Ill stick to what works. Its just money, and for me a piece of mind. BTW I also pay $$$ for Yamalube 15w50 and a OEM filter every oil change.

I also pulled the oil filter while installing Brodies grounding harness. It still looked usable. Half was darker gray and the other half was normal gray. It will need changing during the next oil change, but light was coming through it so it wasnt overly dirty.

Funny thing. I wrote in one of my earlier posts that when the bike is cold and I let it warm up. Before I see any bars on the coolant gauge I would do a slow throttle roll and it would burp at 1500 rpm's. After installing the grounding harness I tried the same thing and didn't get the same results. I am going to ride the hell out of the bike this weekend and start a new test on Monday. I will post any results I get. Also I called my local Yamaha service center, Motoworld of El Cajon, and told them of my plight. The service manager, who has worked on my bike, told me he had another 06 FJR that was having the exact same issue. That bike was getting a new ECU. He told me to bring my bike in and they would check for the same issue. The only problem is they wouldnt get any new ECU's until August due to what is going on in Japan right now. Will also keep updated on this.

 

Slappy

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Update,

On Friday I added Brodies wiring harness to my 07. Once that was completed I also checked the spark plug caps just to be sure they were on tightly. One clicked once and another clicked twice but other than that they were all very snug.

Saturday I rode two up to Orange County. The whole trip was a 201.8 mile day. I know this because that is why I got on the tank of gas. I put in 5.25 gallons. By my calculations that is 38 mpg. How do I go from steadily losing mpg over several tanks to suddenly going back to normal? No it wasnt a loose spark plug cap because this started when the old plugs were getting long in the tooth. They had 15,000 miles on them. That is what I thought was causing the issue, old plugs. After I changed the plugs the mileage contined to decrease steadily over the next 4 or 5 tanks. Suddenly I install a grounding harness and I am back to normal? Someone please explain. BTW Same gas from same station.

 

beemerdons

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Bro' Slappy: I sent johnny80s a nasty ass email for him to stop ripping off your gas! Here's what I wrote: "Hey Goombah, u stoppa stealing Slappy's go-juice! Capiche?"

 
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LAF

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Update,

On Friday I added Brodies wiring harness to my 07. Once that was completed I also checked the spark plug caps just to be sure they were on tightly. One clicked once and another clicked twice but other than that they were all very snug.

Saturday I rode two up to Orange County. The whole trip was a 201.8 mile day. I know this because that is why I got on the tank of gas. I put in 5.25 gallons. By my calculations that is 38 mpg. How do I go from steadily losing mpg over several tanks to suddenly going back to normal? No it wasnt a loose spark plug cap because this started when the old plugs were getting long in the tooth. They had 15,000 miles on them. That is what I thought was causing the issue, old plugs. After I changed the plugs the mileage contined to decrease steadily over the next 4 or 5 tanks. Suddenly I install a grounding harness and I am back to normal? Someone please explain. BTW Same gas from same station.
If you added the wiring harness and you are back to normal, then to me it seems you had/have a grounding issue, or some type of intermittent relay issue. I always hate to cry "The Sky Is Falling" Spider Bite but if a grounding harness gets you strait, just saying.

 

Geezer

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Could it be a bind in the brake mechanism allowing the rear brake to drag?

 

Slappy

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LAF,

As I installed the wiring harness all of the connectors were perfect. No currosion, wires and insullation were like new. There were absolutely no signs of an impending spider bite.

Lets say for sake of argument that my bike was on its way to cooking the ground. By adding the harness will that now stop that from happening or have I just delay the inevitable?

 

Slappy

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Geezer,

read the earlier posts. I just replace the rear pads. There is normal drag, ie a very slight rub, from all of the brake pads. That was the second thing I thought about when I was having this issue.

 

johnny80s

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Bro' Slappy: I sent johnny80s a nasty ass email for him to stop ripping off your gas! Here's what I wrote: "Hey Goombah, u stoppa stealing Slappy's go-juice! Capiche?"
SuperStock_1884-62906.jpg


 

beemerdons

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Johnny, are you saying Beemerdon needs to go sleep with the fishes?
Slappy, you don't have to be Sigmund Freud to figure that one out! johnny80s is probably measuring tu Papa Chuy for concrete overshoes as we speak!

You know he steals your petrol for cheeseburgers!

DSCF1625.jpg


It could be worse I guess, he could be like Niehart and always be dropping his trousers to the ground!

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SkooterG

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So does anyone else around here long for the 'old days' when mi bastard step-pappy didn't know how to post photos?

 

beemerdons

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So does anyone else around here long for the 'old days' when mi bastard step-pappy didn't know how to post photos?
Sleep light mi Hijo (Son), Old Michael is teaching me how to Photoshop. Katy Bar the Door after I acquire that skill!

RockInRoadMexicocopy.jpg


 
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Fred W

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LAF,

As I installed the wiring harness all of the connectors were perfect. No currosion, wires and insullation were like new. There were absolutely no signs of an impending spider bite.

Lets say for sake of argument that my bike was on its way to cooking the ground. By adding the harness will that now stop that from happening or have I just delay the inevitable?
The intent of the harness "fix" is to prevent a failure from ever happening. You are supposed to do it before you have an S4 meltdown. By providing a better, low resistance path to ground you will keep the spider from heating up.

It is remotely possible (although unlikely) that, even though your ground spiders looked pristine, the impedance of the path to ground was causing issues in the fuel injection system that you could not detect with the naked eye. The only way for you to conclusively determine if the harness is what actually changed the MPG (and it wasn't a coincidence) is to remove the harness again and see what happens to your mileage.

The coincidence might be that you got a different (better) fuel mixture on the last fillup? Do you usually fill at the same station? Same pump? (the pump could be metering FUBAR)

BTW - using higher octane fuel than what your engine needs is just pouring your money down the drain. The premium fuel doesn't have anything additional to help keep your engine clean, just octane additive to prevent pre-ignition(detonation). It does not contain any more or less energy than regular unleaded. If you don't have a higher compression engine that is prone to pre-ignition then the higher octane does nothing for you. Luckily, it will not cause any problems either.

 

robinh

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Hi Slappy. I just joined your forum beause I've just had the same Problem!!!

Parked bike up for Xmas and early March I changed plugs, air filter and oil + filter and Serviced the calipers everything as normal. Even the bike runs as normal and when I've had it checked over I've been told it sounds great and runs sweet as can be!!!

BUT my fuel consumtion had gone down to the reserve light coming on at 150 miles. 22.5 liters for 180 miles. That's 25% drop from 48 mpg 2 up to 36 mpg 2 up.

I don't know what I've done but I can now change plugs and air filters during the adverts on the TV.

There are 2 main fuel lines under the tank and the feed was definitely OK but I may have trapped the return pipe.

Anyway before my run out last Sunday I had tank and plugs out again and checked everything to no avail. Put it back together!!

Went on the Run Sunday, 2 up and 180 miles brought me 45.5 mpg. So I'm leaving it alone for a bit. It could just be that Return pipe. Very Srange!!

 

Fred W

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There is no fuel return pipe on 2nd gens. The pressure regulator works differently than on our 1st gens.

 

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