Damn the 'Bird is heavy when you have to push it ! :shock: :evil:

My bike had disapointing fuel consumption from 0 to 31K.... only 30 - 33 MPG. That changed after valve check-up at 31K. It went up to about 40MPG !!! Last Spring (at about 61K) I installed new bags and new slip-ons. On my first long ride to Daytona in March, I notticed my mileage dropped to 34 - 35 MPG. I wasn't sure what caused it. But when I got back, I replaced the sparkplugs and cleanned the K&N filter. The mileage whent back to 39-40 MPG.
It was all good till the temps dropped. The mileage dropped as well. I'm getting about 30MPG latelly but what is more strange, I used to fill up 4.5 - 5 gal, now I can fit close to 6 gal. I usually go to the gas station soon after the light comes on.

Well, today the light came on and I continued for 10 more miles to work.
On my way back I planned to fill up about a mile from the parking lot. While warming up, the bike sputtered and died. It fired back up and I managed to crowl couple of blocks before the bike quit ! :shock:
I still had about three blocks to the gas station, but at least I cleared the bridge, which is a bit uphill....

It sucks to push the bike when you are dressed for cold and out of shape ! :wink: :twisted:
I'm surprissed my heart didn't brake through the ribcage like the Alien. :lol:

Does anyone else experiance the lower mileage in low temps ?

The bike sounded so sweet after I filled it up ! :cool:

(BTW , I put over 6.1 gal in.....)

Cheers,

Well, the gas should shrink in the cold, so you should be able to stuff more in there. If the cold gas get's used, you use more cold gas, so that explains the poor mileage (in my mind). The slip-ons would effect gas mileage, and if you didn't have bags before, that kills gas mileage.

So, most of that makes sense to me, except you being out of shape, aren't you a thin pole? (pardon the pun).

My experience latly with the colder temps is that gas milage has droped a considerable amount. Also on my last trip i found out going a little more then 5 over the speed limit tends to suck down the fuel quickly. :twisted:

Well, the fuel injection will compensate for the colder air temps by adding more fuel. The cold air is denser than hot air and if you don't add more fuel, it will be leaner than normal. You should have more power with the cold air but with reduced fuel mileage.

Cold air is awsome.. Felt the front end get light the other weekend when I smacked 3rd gear :shock:

Higher fuel consumption is normal in the cold weather,longer warm-up with rich mixture,more wasted fuel.
Ram air is good for max power but also makes engine suck outside air.
Great in the summer ,but in cold air fuel vaporises poorly,more fuel waste.
Airbox on many cars can suck outside or warm heated air from exhaust manifold area.It is controlled by "flip valve" with some sort of thermosensor.
On old FIATs it had to be done manually.Cold air for the summer,warm for the winter to conserve fuel.

:shock: :shock: :shock: :shock: :shock:

I have Never broke into the 6 gallon range.... I think you pushed your luck just a little too much that time.

As for your mileage fluctuation... sound like a bach of bad gas... been there, done that, and it really screws with your head. You keep thinking "what could it be?"

I noticed a considerable drop in mileage once the cold weather set in,
from a normal summer time average of around 40 to near 34 now.

...and I pushed the bike a little too ! :twisted:

Four city blocks can be quite a distance ! :shock:

The bike run well in the snow today though .... :wink:


Cheers,

I don't know about the states but up here the gas pumps are "volume corrected to 15 degrees celcius" That means that as the gas shrinks the pump compensates the readout on volume distributed. You put in 15 Litres, it reads more like 20 but you actually only have 15 litres of fuel in the tank. The reasoning behind this is that as the fuel shrinks it contains more potential energy per unit of volume and the gas station wants to make their money on that potential energy. This works okay in cars because cold fuel actually does contain more potential energy if it's burned right (warm air). But on a bike where it is sucking cold air from a ram air system it doesn't burn to its full potential as the flash point is harder to obtain. This would account for your decreased fuel milage.

Bearing in mind that I'm NOT a physicist and these are just observations as I understand them. :roll:

Peter:

I've noticed my mileage sucks in the winter, too. Instead of getting 185-200 miles before it's flashing, I'm getting 150. I figure when it warms up it will improve.

However, I'm probably going to have the valves adjusted over the winter (just because, at 40k, it hasn't been done yet) and while that's being done, I'll clean the K&N, so.... for all I know, mileage will change once that's done anyways.

Sorry ya had to push your bird, though. At least it wasn't full of gas, that extra weight would have made it really suck. :lol:

It's partly due to air temperature, but they actually (at least where it gets cold in the winter) mix the fuel differently. They mix it so it's easier to burn, but you have to burn more of it. You see it in cars all the time... You'll notice, if you check your mileage in the winter every tank... as you go south to Fla. or something, you'll notice all of a sudden your gas mileage goes up drastically when you've been doing the same kind of driving... this is because you've gotten south enough that the last gas you got was the summer mixture.

Mike

Just ride the hell out of it and keep it full. I didn't buy the bird for fuel mileage and don't really check it. I have fun trying to run my tank out as quickly as possible.

Were your valves ACTUALLY adjusted or just checked at 31 K miles? Just looking at them wont change your mileage. Unless 1 or more valves were stuck open (not enough clearance) It wouldn't affect MPG like that.

I'm at 52K miles and wondering if I should go in there and check again. Been fine the last 3 checks.

I don't notice any change from cold to hot with MPG but then I have carbs.

I track fuel milage in my truck pretty closely, I reset the MPG every tank.

The milage always drops off when the cold weather hits, by as much as 2mpg, which is a lot when you consider I'm only getting 12mpg even when it's warm out.

I'm with the "blame it on the weather" contingent.

:shock: Why? You must really pick your routes based on the number of gas stations.

Cold air is part of it, but the other part of it is how much ethenoll is put in the fuel... if I remember correctly, it's more ethenol in the winter.

Mike

I always feel I have to pay more to live here in the good weather so it's nice to know that someone has to pay more for the bad weather. :razz:

[quote=Redbird]I'm only getting 12mpg even when it's warm out.[/quote]

:shock: Why? You must really pick your routes based on the number of gas stations.
[/quote]
In the truck, not on the bike. Luckily it has a 34 gallon tank :wink:

Pete, the dealer told me they just checked the valves, there was no need to adjust anything. Yet the bike seemed to run more smooth and the mileage improved....


Cheers,

On the subject of winter gas mileage; I feel certain thee is a drastic change in winterr formulation of gas in Northern states, and this decreases our MPG.

I drive a Honda Civic Hybrid, where I use cruise control all day long, running at exactly 72 MPH. On the interstate I ALWAYS get exactly 48.5 MPG, in warm weather, using the air conditioner. On a recent 1600 mile round trip out to Wisconsin, I got as far as Indiana before I needed to fill the tank the first time. As the trip went, my mileage was low to start with, then dropped all the way down to 35 MPG. My car is in perfect tune, and the only reasonable explanation I heard was the change in gas formulation for the season. Also, in the midwest, they use ethanol mixed with the gas, and in Wisconsin, they have further additives for EPA reasons. When I got home, my around town mileage returned to normal.

On my Blackbird, I found that by using 87 Octane, I was running badly and getting terrible gas mileage. When I started using 93 Octane, the bike ran much better and got more normal mileage.

My mileage is down considerably. In my case, I haven't noticed any difference in gas mileage from cold winters to hot summers. My bad gas mileage started last summer. I've got a carburated model. I can't figure what happened. I use to get to 180 miles before the fuel light came on. Now, it comes on at 150 miles. What could it be?

Thanks

Are you riding it harder now?

Check tire press. brakes dragging, get a new air filter.

... and maybe new spark plugs....



Cheers,

Fuel gauge must be cupped :roll:

I been riding no harder than usual. Checked and spun my wheels. Checked for brake drag. Checked my tire pressure.

I found some info on the Super Black Bird forum that might have something to do with it. You can put more gas in the tank when the bike is on the centerstand. I'm thinking, maybe, my sidestand is causing the bike to lean over farther than it use to and I'm not able to fill the tank up like I use to. I'm going to check the sidestand and do a fill up on the centerstand.

The difference between sidestand and centerstand fill ups is only a few ounces. It shouldn't be enough to throw off your total tank milage by any signifigant amount.

Are you filling it up only to the point where the nozzle stops? If this is the case you can get almost another 1/4 - 1/2 gal in usually. I always place my bikes on the center stand when filling, sometimes that's a bitch when it's loaded though.... or when I loaded too.

<The difference between sidestand and centerstand fill ups is only a few ounces. It shouldn't be enough to throw off your total tank milage by any signifigant amount>

You're right. I filled it up on the sidestand. Then I sat on the bike and was only able to get another 2 tenths in. Took a nice long ride cruising the interstate at about 85mph and the light came on 163 miles. Checked the brakes, again, and the rear one might be dragging a little.

The only other thing I can think of is last summer I had the valve clearances checked at the dealer. Is the service manual pretty straight forward and without any mistakes in it on valve inspection?

Thanks,
Mark

[quote="R.C.XX

The only other thing I can think of is last summer I had the valve clearances checked at the dealer.

Thanks,
Mark[/quote]

That's the problem. dealer probably left a shop rag in the airbox. :roll: