Ok folks,
As you know I have an '84 FJ1100. 74K miles, runs like a top. But lately my gas mileage has been rubbish. Typically I get between 36 and 38 MPG, but recently (the last three tanks of gas) I've been around 32, 33mpg. No difference in riding style, terrain, or anything else. The bike has a Vance and Hines Supersport exhaust with a stage two jet kit, stock airbox. MY gearing is 18/39 if it helps. I changed the plugs and filter approximately 8K miles ago, when I did a valve adjustment. I'm kinda stumped as to what I should do. I figured I'm about do for a new air filter, and was thinking about going to pods, but If I do so will I have to rejet the carbs, and if so will it make my gas mileage even worse? I frequently ride to work instead of taking my truck and I'd like to get the best mileage possible. I certainly don't need any more oomph than my bike already has, especially if it means a hit in my mileage. Any suggestions? Cheers in advance for any help!
Dennis
Dennis,
Bike been sitting in a cold garage all winter? Was she prepped for winter, like with stable or other fuel stabilizer? Any gas smell coming from her after a ride? Might want to buy some Seafoam and run it though a couple of tanks. Let it idle also with the Seafoam in it.
Might want to check the air filter as well.
I think your pilot jets may have some varnish in them. Just a theory. Might just clean it up and save yourself some work.
Regards,
CraigO
90FJ1200
Quote from: E Double on April 15, 2011, 09:49:15 PM
I'm about do for a new air filter, and was thinking about going to pods, but If I do so will I have to rejet the carbs, and if so will it make my gas mileage even worse? I frequently ride to work instead of taking my truck and I'd like to get the best mileage possible. I certainly don't need any more oomph than my bike already has, especially if it means a hit in my mileage. Any suggestions? Cheers in advance for any help!
Dennis
My experience with combustion tells me "more air in, more gas required." Otherwise, your mixture will be lean. More gas in means mpg will drop.
Quote from: craigo on April 15, 2011, 10:38:55 PM
Dennis,
Bike been sitting in a cold garage all winter? Was she prepped for winter, like with stable or other fuel stabilizer? Any gas smell coming from her after a ride? Might want to buy some Seafoam and run it though a couple of tanks. Let it idle also with the Seafoam in it.
Might want to check the air filter as well.
I think your pilot jets may have some varnish in them. Just a theory. Might just clean it up and save yourself some work.
Regards,
CraigO
90FJ1200
Craig,
Thanks for the reply. I rode all winter, with the exception of three weeks in January when we had all of the snow. Luckily for me my garage is connected to the house; The coldest I've ever seen it in there was the low 50's, and that was when it was 5 degrees outside. Usually it's in the upper 50's to low 60's inside all winter. I ran a few bottles of Sea Foam through it over the winter, basically whenever I thought I wasn't going to ride at least once every week to ten days. Typically I went out more than I didn't, putting about 3K miles on it since January. I also ran a tank of sunoco 100 octane racing fuel through it immediately following the three week snow break. I put some in every two or so months just to blow it out. I wish I could run it more frequently, but at almost $8 a gallon I have to get it as a treat. I'll put some in next week just to tighten it up; hopefully that will help. I'll also check the filter. Cheers
Sticking brakes, chain wear, other parasitic losses...
Float level too high or needle seats leaking a bit, ovalled emulsion tubes? Are the emulsion tubes original or were they replaced with the jet kit? Higher ethanol level in the gas you're using? What was the mileage with the 100 octane?
I'm drawing a blank on the status of the emulsion tubes, as I am my mileage with the 100 octane. I'm going to be filling the tank up with it next week so I'll report the mileage then. I want to say it was around 38-39 mpg, but I've been wrong before. The fuel is definitely a possibility, because I've found that the way this particular bike tells me it doesn't like the gas is by the mileage. It'll still run fine. And I noticed this year that the bike can't sit for more than 10 or so days without some seafoam in the tank without having problems starting the first time I would fire it up. Also my truck's ('98 F150 2wd, 4.6) mileage has been fluctuating too; Over the winter my worst mileage was 13.5 doing mixed driving; I typically see 16-17 mixed and 19 highway. The gas definitely sucks, that's for sure. If I don't see an improvement after a tank of the 100 I'm gonna take it over to my favorite local shop (Sun Cycles, Manasquan, NJ) and have them put it on the dyno. Money's a little tight, but I don't get on with riding/driving a vehicle around when it may need something so I'll have to do what I'll have to do.
OK this is a real long shot.
In winter fuel contracts in size so you get more for your money, then as the temps creep up the fuel expands a bit so you don't get as much for your money.
Told you it was a long shot :rofl2: :wacko3:
Unless you have a need for the 110 octane it will actually hurt performance and mpg.
If your running 12-1 comp with 5 % advanced timing then you need high octane if you have stock comp then you dont.
Get new plugs and look at the carbs,when did you last sync them.Go though them and check float heights.
I dont see 110 octane as helping mpg :hi:
Quote from: E Double on April 15, 2011, 09:49:15 PM
Typically I get between 36 and 38 MPG, but recently (the last three tanks of gas) I've been around 32, 33mpg. No difference in riding style, terrain, or anything else.........
Quote from: FJ111200 on April 16, 2011, 10:33:18 AM
OK this is a real long shot.
In winter fuel contracts in size so you get more for your money, then as the temps creep up the fuel expands a bit so you don't get as much for your money.
I think our British friend is on to something .... Here's why:
Hey Dennis, you know that the EPA requires the oil companies to sell different blends of fuel, based on the season, correct?
The cold temp. winter blend is different than the hot (warm) weather summer blend.
A 10-15% variation in gas mileage could be due to the difference between the summer/winter blends.
Before freaking out and start changing things, let the season mature until the warm weather blend hits the pumps, then check your mileage.
Winter fuel formulations I didn't think applied everywhere? Another question is if ethanol was recently added to your local pump.
Sounds like a fairly big loss in a percentage basis, but if the car is doing it as well, try getting fuel elsewhere. The tanks that are changed over first will be the most popular one, probably a lo-test fuel in a convenient station.
I get fuel all over; This is especially the case with the bike. Typically I fill up local and then do a 250-350 mile ride every weekend. I'll fill up at about 150-175 typically at the middle of the ride, which is always away from Toms River. I will say this; I've put about 1200 miles on the bike over the last month and every time I've gotten fuel in NW NJ (Warren, Hunterdon, and Sussex Counties, About 100 miles NW of me) I've been consistently getting better mileage per tank than I do at the local stations (Shell, Sunoco, Wawa- I try to rotate where I get fuel from locally after getting a bad tank of gas in my wife's car at a station she frequents)over the past 6 or so weeks. Its just odd because I got better mileage all winter (with the exception of one or two tanks in the dead of winter, when I was putting sea foam in and running a lot of heated gear) than the last two weeks, typically 36 or so mpg. I saw a drop from around 37-38 mpg when October came around, which is when the crappy winter gas comes online, and then it stayed at 36 all winter until now. Who knows? maybe they have excess winter gas to get rid of and they're dumping it locally? As for the ethanol the stations around here have been running 10% for years; In fact I can't recall a time when they didn't in the years I've been in the area.
I think Pat has the right idea though, with waiting a bit to see if the warmer weather brings my mileage back up. Its running like a top (really as it always does) and there are other things on the bike which will soon need my attention, such as a new rear rotor and pads and fresh rubber for the summer.
just blame gravity and friction. i do.
no to threadjack but i'm having the exact same problem. only thing is, i've completely rebuilt my carbs. i went with Pat's suggestion of #40 pilot jets and adjustable needles set at the #2 clip. 2.5 turns out.
stock airbox with uni filter and V&H 4-1. but my mpg is horrible. last tank i got 100 miles to 4 gallons. that 25mpg! i did rail on it a little, but that's a bit much.
what kinds of mileage do you guys experience while giving it the beans? i tend to ride pretty fast. but even when i'm flying with my r6, i still get 150 miles to 3.5- 4 gallons
i do have the colortune and gave that a shot, but i haven't really seen a difference. it's got all new wheel bearings and front brakes are newer r1 calipers. the rear is OE, i'll check it but that doesnt seem like the problem.
WTF? any suggestions?
Quote from: wakdady on April 20, 2011, 05:53:34 PM
WTF? any suggestions?
Emulsion tubes...?
I don't think you got those when you bought all of the other parts, but I do not recall for sure. If they are ovaled out the bike will be rich.
Plus, I can tell you that I noticed my tow van I used to go racing last weekend only got about 11mpg compared the the normal 14-15. The fuel might be the cause since we live here in the "green" state of California.
I have also gone away from running "premium" pump gas in my race cars this year as I was seeing higher head temps due to the alcohol content, I have gone back to running 100 octane race gas.
Randy - RPM
the emulsion tubes were included. it was the keyster kit. i replaced all the bits in there. oddly enough there was one mixture needle missing, so i just used the old one.
it seems to be running alright. no flat spots, no high/low idle. power is linear with no hicups.
although when you really give it the beans as the revs climb, you could feel something happen and then the clutch gives and the revs go up rather quick
but, it smells like shit! kinda like old gas. not unburnt fuel smell when you run rich. but just an overall foul odor to it.
what could that be?
Took a road trip to Indiana Saturday and I got about 5-6mpg better mileage than i see when im on and of the gas.
Scott, what do you normally get? I'm guessing it's low from your tales of GPS.
Typically 30 mpg I got 37+ on the trip.
Nice, I'll report in when I finish my first tank of this year's gas.
Have you checked the carb diaphragms? If those are punctured the juice spent is a clear symptom
Another option to increase performance and sometimes mileage is to upgrade. an NGk Iridium IX plug makes a big difference.
Those are the plugs I use now.
I think I'm running a little rich, but I'm not going to be taking it apart for a while, so I'm keeping an eye on my mileage.
Huzzah! Huzzah! I was out for a nice ride today. First tank (I filled up part way into the ride, because I rode to work the previous two days and didn't fill up after) I got 36 mpg. Second tank was even better, at 37.4 mpg (and that included 15 miles of city traffic). I doubt the 100 miles I rode after my last fill up home will be as good, because I was in that motor's behind like it owed me money; Every awesome road I was on that normally have a lot of traffic on them on a Saturday was wide open-no po-po, no nothing! I went 295 miles today through 5 counties in NJ and 2 in PA, and only saw one active patrol car, and that was in New Hope, PA (which is nuts in itself). All told it was an awesome day! :yahoo:
Those are great rides, lots of Kookalo and no Johnny long arm too screw with you. :yahoo:
Bob W
Quote from: weymouth399 on April 30, 2011, 08:01:59 PM
lots of Kookalo and no Johnny long arm to screw with you. :yahoo:
We spell that R-A-L-L-Y.
Quote from: E Double on April 30, 2011, 07:58:08 PM
I went 295 miles today through 5 counties in NJ and 2 in PA, and only saw one active patrol car, and that was in New Hope, PA (which is nuts in itself).
No kidding. I have been to New Hope, [PA] and watched the cops at the edge of town, pull over each of the bikes as they came to town and tested their exhaust sound. Most bikes, (even some with bone stock exhaust!!) were ticketed. They are bastards. I do not go to that ridiculous town anymore.
Dan
Quote from: Dan Filetti on April 30, 2011, 10:16:43 PM
Quote from: E Double on April 30, 2011, 07:58:08 PM
I went 295 miles today through 5 counties in NJ and 2 in PA, and only saw one active patrol car, and that was in New Hope, PA (which is nuts in itself).
No kidding. I have been to New Hope, [PA] and watched the cops at the edge of town, pull over each of the bikes as they came to town and tested their exhaust sound. Most bikes, (even some with bone stock exhaust!!) were ticketed. They are bastards. I do not go to that ridiculous town anymore.
Dan
I don't make a habit of riding down the main drag of New Hope; Basically its no less shitty than Seaside Heights and the like, just on the Delaware. Or (god forbid) South Street in Philly on a weekend night. There are so many detours in the area right now I just happened to amble on through, pretty much by accident. I have seen them pulling over bikes from time to time, but typically on the south side of town. We usually come over from Lambertville and immediately head north on 32, avoiding all of the fools, drunks and babies.
I'm mad; apparently gas stations in and around central NJ only stopped using winter blend gas this past week. Of course I stumbled across a station a few days ago that still had that bullshit. 32 mpg on a tank full of easy riding. :ireful:
Here in Phoenix we have the "10% Ethanol Blend" all year round............We have bad air pollution problems here.
I do notice a shift in fuel milage between winter months, and summer months, but I don't think it has anything to do with the fuel itself......
My reasoning leads me to believe it has to do with the CV carbs, and the way they meter fuel at different densities.
We have quite a huge shift in air temps between winter and summer.
My '90 has a factory set of carbs that I got from Bob (XJR maybe?), and a Kerker 4-into-1 system.
During the colder months, when the air is more dense, I get around 37-38mpg on an average tank riding around Phoenix.
If I ride up north in the higher altitudes, say 5000+ feet, I get around 42-43. I am guessing that because the air is thinner, it doesn't draw as much fuel as it passes through the carbs.
The same applies during the summer months down here in Phoenix. When the air temps are 100+degrees, I average around 41-42mpg.
Anyway, maybe this isn't exactly how it works, but since I'm using the same fuel all year, it's the best I could come up with. :mail1:
Mileage figures obtained by cruising like a responsible adult...........Mileage may vary with throttle usage, and how much "Kookaloo" is obtained.
I notice 10-20% change in mpg across every vehicle I own when going from winter to summer blends.
Besides the snowblower, lawnmower and the FJ everything else is fuel injected.
So at least here, it must be the fuel.
First tank of gas done with, 199 miles and 5.09 gal = 39.1 mpg. That's probably 5 rides with some redline but most cruising in the 4-5K range. No idea about ethanol content or even octane, most likely it was 10% and 87.