Poor Gas Mileage?

[Bones85]

I filled up my gas tank nearly to the top a couple days ago and so far I've rode about 123 miles and I noticed that gas gauge is on the quarter tank bar already.

I looked in the gas tank and it appears that a lot of gas has been used so far, although it's hard to judge exactly how much is left in the tank. Oil was changed about 1,000 miles ago and the air filter and spark plugs about 1,400 miles ago. Tire pressure is fine. Chain is always cleaned and lubed. I weigh about 140-145 pounds. I always stay below 6,000rpm when first riding and ride with the choke on for about a minute or two. 95% of the 123 miles were at speeds above 40-50mph and I generally shift into 6th gear fairly quickly. I ride like a granny most of the time, only occassionally accelerating fast or riding at higher speed than traffic.

What else can I do to improve the gas mileage?

Thanks.

[allanoue]

The gauge is notoriously not accurate. The only reliable way to know how much gas you used is to fill up to the same spot as the last fill.

[choneofakind]

^^ Also, 123 miles should be about half a tank. 50 mpg is pretty average.

[Motofool]

Joe,

Check for small leakage around your petcock, hose and carburetors' bowls.

Wrap some toilet paper around those parts after you stop and park, then check for stains of fuel the next day.

My pregen calls for reserve after 200 miles of a fill up to the neck of the cap, riding mostly at 70 ~ 80 mph on I-95.

125 miles is only 60% of that.

You did not mention valve's adjustment.

[Alex]

Figure out exactly what your mileage is before doing anything else (or even worrying about it). Estimating by looking at the gauge or even just peering in the tank won't tell you much useful information.

[kirk595x]

Any chance you may have left the choke on at any point?? I've done that coming home late from work and forgeting i left it on. Going 70 miles with the choke on a quarter really eats up the fuel..lol.

[bfpower]

Originally Posted by kirk595x

Any chance you may have left the choke on at any point??

This.

I check my MPG every time I fill up. This week I was riding in 10 degrees F so my choke was on most of the time. I got 25 MPG.

[CC Cowboy]

Did you buy "poor gas" to get this mileage?

[bfpower]

Originally Posted by CC Cowboy

Did you buy "poor gas" to get this mileage?

That was a bit of a poor joke, no?

[Bones85]

Sorry to bump this, but I'm still having a problem.

I filled up the gas tank all the way to the metal ring and reset the trip odometer. I rode 186 miles before the gas tank was completely empty.

186/4.8 = 38.75mpg

I'm not sure what's going on because almost all of the 186 miles were in 6th gear ranging from speeds 40-80mph.

Could it be a bad batch of gas?

[Alex]

Why are you dividing by 4.8? How many gallons did you actually add to the bike (what did it say on the pump).

[sLick415]

Tank only holds 4.2

[Alex]

I thought the new-gen was 4.5 (pre-gen was 4.8), but that's somewhat beside the point. Even if you've run the bike completely dry, and pushed it up to the pumps, getting 4.5 gallons in might still not even be possible, if there's still a little fuel in the tank that didn't drain out fast enough to keep the carbs running all the way til empty. To find mileage, you need to divide the trip odometer by the number of gallons added, and make sure that you fill up to the same level in the tank each time for accuracy.

[bfpower]

Originally Posted by Bones85

I filled up the gas tank all the way to the metal ring and reset the trip odometer. I rode 186 miles before the gas tank was completely empty.

You can't depend on tank size. Just fill to the exact same spot on the tank every time, and check the pump to see how much gas it took to refill the tank. Use that number and your trip odometer to get your MPG.

This time of year I never break 40. I don't even break it often in the summer.

[DaBlue1]

Originally Posted by Bones85

Sorry to bump this, but I'm still having a problem.

I filled up the gas tank all the way to the metal ring and reset the trip odometer. I rode 186 miles before the gas tank was completely empty.

186/4.8 = 38.75mpg

I'm not sure what's going on because almost all of the 186 miles were in 6th gear ranging from speeds 40-80mph.

Could it be a bad batch of gas?

How much gas did you put in it to fill it up?



1. Your math is probably a little off. Even though the manual says the tank capacity is 4.8 gals, you technically can't get 4.8 gals of fuel in the tank. Approx .4 gal is air space and unmeasured fuel. Even with the needle on "E", you can travel about 45 miles @ under 45 mph. So when you completely fill up with the tank truly empty, you should be putting in around 4.2-4.4 gals, providing the bike is level.

2. Warmer temps can make the bike run a little richer and high rpm speed over 8k really decrease mpg. Time spent idling also eats into gas mileage as well as any intake mods. If you get between 50-60 mpg, your doing good. The average Ninja 250 even at Hwy speeds can average 220-240 miles to a full tank.

3.There are a few things that can improve your gas mileage. Run synthetic oil, install Iridium Spark Plugs, Replace the stock filter with a direct replacement one that breaths better. Install a 15 tooth front sprocket or a 43 tooth rear to lower the rpm speed.

[Bones85]

Are you sure the new-gen gas tank only holds 4.2 or 4.5 gallons? The website and manual says 4.8 gallons.

Also, I haven't went to the gas station yet because I didn't have my debit card on me. I just used gas from a gas can so I could get home.

All I know is that I filled the bike all the way to the metal ring when the bike was level and was only able to ride 186 miles before the tank was completely empty.

Even if the gas tank only holds 4.2 then that means I only got 44.3mpg, which is still terrible for the type of riding I do.

Originally Posted by DaBlue1

3.There are a few things that can improve your gas mileage. Run synthetic oil, install Iridium Spark Plugs, Replace the stock filter with a direct replacement one that breaths better. Install a 15 tooth front sprocket or a 43 tooth rear to lower the rpm speed.

I use Mobil 1 Racing 4T 10W-40 or Shell Rotella T6. Spark plugs are the stock ones - NGK CR8E, just replaced them approximately 2,000 miles ago. Air filter is K&N KA-2508 and was replaced when I did the spark plugs.

I only let my bike idle for approximately a minute before riding off with the choke partially on and I always turn it off within a few minutes of riding.

Originally Posted by DaBlue1

Even with the needle on "E", you can travel about 45 miles @ under 45 mph. So when you completely fill up with the tank truly empty, you should be putting in around 4.2-4.4 gals, providing the bike is level.

I don't believe my gauge even made it to the E. It was on the bar above the E and then all of a sudden I was out of gas and the bike started shutting down.

[Motofool]

Originally Posted by Bones85

Are you sure the new-gen gas tank only holds 4.2 or 4.5 gallons? The website and manual says 4.8 gallons.

Specs of the pre-gen say 18 liters total capacity, which are equivalent to 4.755 gallons.
Out of that, 1 liter (0.264 gallon) is kept in reserve.

From full tank to the need to use the reserve, my pre-gen bike should easily cover 190~200 miles; even more if I am going slow.

Specs of the new-gen say 18 liters total capacity as well, although it doesn't have a reserve volume as pre-gens do.

Your mileage is still low, and you may want to locate the cause as suggested above.

Your problem is that gas vaporizes as soon as it leaks out; so, the path is hard to find.

[NevadaWolf]

How long were you riding at the upper end of your 40-80mph range?

I found if i keep my speed below 65 indicated (60 on the gps) i have average 60-70mpg. But as soon as i go 70 indicated (65 per gps) my mpg drops to the mid50's. For that reason I rarely ever go over 70.

May be part of the issue. :shrugs:

[sLick415]

Oh it is 4.8. Where on earth did I get 4.2

You really need to take note at the gas station how much was filled at the pump. You cant just assume you filled it with 4.8 gallons.

[DaBlue1]

The tank's capacity is 4.8 gals, however you can not put a full 4.8 gals of full in it the normal way. There is a small amount of air space that you can't fill, also there is a small amount of fuel left in the tank when it is on "E". Unless you completely dry the tank turn it upside down and fill it from the bottom, then you may be able to get the full 4.8 gals of gas in it.

What you have to do is completely fill up the tank as much as possible, set the odo to zero and ride the bike until it almost quits. (you'll know when you start loosing power. slow down to about 45 mph, or use about 1/4 throttle, you'll be able to travel a little further). Fill up and see how much fuel you put in. Take your mileage and divide it by the gals of gas you put in. That will give you a closer average.

[DaBlue1]

Originally Posted by Bones85

....I don't believe my gauge even made it to the E. It was on the bar above the E and then all of a sudden I was out of gas and the bike started shutting down.

When your gas gets low it will do that. The fuel system is a gravity feed system. It requires the weight if the fuel itself to feed the carbs. It is also possible for the the bike to slow down while riding on a flat surface if the fuel is too low. The carbs tend not to fill up as fast. Any amount of throttle more than 1/4 results in a non response. The jet needles tend to start moving at this point and the carbs draw more gas. Low gas, go slow.

[broilmebk]

Originally Posted by sLick415

Oh it is 4.8. Where on earth did I get 4.2

You really need to take note at the gas station how much was filled at the pump. You cant just assume you filled it with 4.8 gallons.

He filled it out of a gas can.

OP you should go to the station and record the actual number of gallons filled up for better calculations

[sLick415]

Originally Posted by broilmebk

He filled it out of a gas can.

OP you should go to the station and record the actual number of gallons filled up for better calculations

Yeah I know. Poor wording on my part..

[Bones85]

Do you all think any damage was done by running the tank completely dry? I was going 70-80mph when I ran out of gas.

[allanoue]

only if you pull something, pushing your bike home

[menikmati]

Originally Posted by Bones85

Do you all think any damage was done by running the tank completely dry? I was going 70-80mph when I ran out of gas.

I've run out of gas before, no harm was done.

[DaBlue1]

Originally Posted by Bones85

Do you all think any damage was done by running the tank completely dry? I was going 70-80mph when I ran out of gas.

When did you run the tank completely dry?

[Bones85]

Originally Posted by DaBlue1

When did you run the tank completely dry?

Today.

[rojoracing53]

I didn't think it was necessary but I'm starting to think I need to make a DIY on how properly fill up and calculate MPG

It's not the hard if you use a little common sense

[DaBlue1]

Originally Posted by Bones85

Today.

How much fuel were you able to put back in it?

[rojoracing53]

Oh and I've actually added 4.8 gals to as NewGen. Ether I was totally empty or I got ripped off but I was at 250 miles on that tank.

[lgk]

Maybe you should check other things that effect gas mileage.
Tire pressures, chain maintenance, brakes, and leaks all cause the bike to consume more fuel.

[DaBlue1]

Originally Posted by rojoracing53

Oh and I've actually added 4.8 gals to as NewGen. Ether I was totally empty or I got ripped off but I was at 250 miles on that tank.

It is not uncommon for some random pumps to read a little high. One guy with a new gen says he put in 5.03 gals in on a fill up one time.

[StephenA]

on a semi-related question, in order to lower rpms(and get better mileage) would it be better to change the front sprocket to a 15t or the rear to say a 41t?

[DaBlue1]

Originally Posted by StephenA

on a semi-related question, in order to lower rpms(and get better mileage) would it be better to change the front sprocket to a 15t or the rear to say a 41t?

Most start out with a 15t.

I run a 15/41 for the majority of riding I do, which is Hwy and long country roads. My average rpms range from 5.2k (6th gear @ 50.8 mph) to about 8.2k (6th gear @ 79.9 mph)

[Alex]

Wouldn't hurt, but if just changing the gearing and then riding exactly the same speeds/acceleration as before, usually results in a limited improvement in fuel mileage. There's more to be gained by changing riding/shifting/acceleration styles, if one is trying to optimize efficiency.

[StephenA]

Originally Posted by DaBlue1

Most start out with a 15t.

I run a 15/41 for the majority of riding I do, which is Hwy and long country roads. My average rpms range from 5.2k (6th gear @ 50.8 mph) to about 8.2k (6th gear @ 79.9 mph)

sweet, because i do a lot of highway riding, which means i'm typically going 70+ mph and was wondering on how to lower the rpms. Also, what chain do you use?

[DaBlue1]

Originally Posted by StephenA

sweet, because i do a lot of highway riding, which means i'm typically going 70+ mph and was wondering on how to lower the rpms. Also, what chain do you use?

I'm still on my stock chain, but after this riding season, I'm getting a new one. Depending on how many teeth you go down on the rear, you may what to shorten the chain length by a couple of teeth.

[StephenA]

Originally Posted by DaBlue1

I'm still on my stock chain, but after this riding season, I'm getting a new one. Depending on how many teeth you go down on the rear, you may what to shorten the chain length by a couple of teeth.

is there a way of figuring that out? or is it up one, down one kind of thing? also, the new gen sprockets and chains fit the new gens correct?

[choneofakind]

Originally Posted by StephenA

is there a way of figuring that out? or is it up one, down one kind of thing? also, the new gen sprockets and chains fit the new gens correct?

Info on pregen chains:
http://faq.ninja250.org/wiki/What_re..._I_consider%3F

I believe both the pregen and newgen use 520 size chains, but they are different lengths. I'm also fairly positive that the countershaft sprocket are different. The newgen uses a nut to tighten on, the pregen uses a little bracket that bolts onto the sprocket and basically jams it onto the slot in the splines.