Recent buy really bad gas mileage

[silverchair19]

2007 250r
bought it last month and have run through 3 tanks of gas including reserves
I have done a full tune and oil change
I have used a small amount of sea foam in the first and 3rd tank.
my idle is set at 1600rpm
I'm at around 130 miles per tank. (27-28 mpg)
I romp on it maybe once per tank I'm very concious about gas mileage my other vehicle is a 4 cyclinder.
this is my first bike so I don't know what else to look at.

[allanoue]

Tire pressure
chain tension
fuel leak

[Motofool]

Originally Posted by silverchair19

........
I'm at around 130 mpg per tank.

Welcome, Jay !!!

Do you mean that the bike is doing 130 miles per gallon or that you can only cover 130 miles using a full tank, including reserve?

[allanoue]

Originally Posted by Motofool

Welcome, Jay !!!

Do you mean that the bike is doing 130 miles per gallon or that you can only cover 130 miles using a full tank, including reserve?

LOL

I read it as 130 miles per tank.
He would not be concerned about getting 130 MPG?

[Brother Michigan]

If you really want seafoam to do its business, I'd use at LEAST the recommended dose. If you suspect your carbs are really gummed up, I'd fill the bowls with it and let it sit for a day. It will smoke like crazy after you start it, but it will be clean.

[silverchair19]

I get 130 miles to the whole tank including reserves about 115-119 til I switch to reserves.. I checked for leaks and found none. The bike only has 2400 miles on it I just don't get why this bike would be having this issue when I see everyone claiming 40 mpg as their minimum. I'm now shifting at lower rpm (4-5 k rpm), not sitting upright, and I adjusted my idle to 1,600 rpm. It was set at about 1,900 -2,000 rpm. I also just filled the tank and added double the sea foam from last time. Has anyone else had a low mpg like this?

[Motofool]

Originally Posted by silverchair19

I get 130 miles to the whole tank including reserves about 115-119 til I switch to reserves.. I checked for leaks and found none. The bike only has 2400 miles on it I just don't get why this bike would be having this issue when I see everyone claiming 40 mpg as their minimum. I'm now shifting at lower rpm (4-5 k rpm), not sitting upright, and I adjusted my idle to 1,600 rpm. It was set at about 1,900 -2,000 rpm. I also just filled the tank and added double the sea foam from last time. Has anyone else had a low mpg like this?

You should be needing to switch to reserve around 180 or 200 miles after a fill up.

You may have a float valve that is leaking badly with the vibration of the engine and overflowing the bowl.

This may be happening only when the engine is working, producing vacuum to activate the petcock and vibrations.

If happens when the engine is off, then some fuel is going into your oil in the crankcase, increasing the volume and ruining the oil.

[Ghostt]

How much your you filling up? As in how many gallons??

The tank holds about 4.8 gallons if you fill it up to the tippy top. The reserve is about the last .8 gallons, so if your petcock is working right, and the fuel feed tubes it should take about 4 Gallons.

http://faq.ninja250.org/wiki/How_doe...e_tank_work%3F

Is the 100% stock? Any modifications??

@Alex this needs to be moved to the PreGen section

[Alex]

Originally Posted by Ghostt

@Alex this needs to be moved to the PreGen section

[silverchair19]

No mods and I fill it to the very top everytime. I did notice today the exhaust smells really rich bit I'm told the bike runs lean from the factory. I forwarded what you guys suggested to my friend who works on bikes he said he will take a look and let me know.

[Ghostt]

No modifications as far as you know of, doesn't mean a past owner might have done something.

Your list of causes is long, jet kit? Leaking petcock, sucking gas thru the vacuum side? Bad and/or improper float heights, and float needle valve, etc.........

[csmith12]

Check your oil, is the level rising and smell of gas? If so, you have a float stuck and it's leaking into the case.

After you park your bike, lean it over pretty good to each side. Any leaks? Many pregens have tank leaks where the fairings bolt to the tank due to the owners using screws that were too long. it could be leaking while you ride.

Good luck and let us know.

[dcj13]

So what is your actual measured miles-per-gallon?

(rather than miles per fill-up)

[cadd]

Originally Posted by dcj13

So what is your actual measured miles-per-gallon?

(rather than miles per fill-up)

I would guess around 35mpg from the info he provided.

I think there's a possibility the bike may be running rich as well. But first, do what Motofool mentioned. Check the petcock. In it's original position, there should not be any fuel dripping at all.

If you see fuel dripping, will enter the carbs. And if your float needles aren't in great condition, they will allow fuel to flow pass the carbs, through the motor and into the crankcase.

Do a quick test. Open the oil cap and take a sniff and see if you there's a big whiff of gasoline smell.

Also take out your air filter and see if there's any gasoline smell in the airbox.

[dcj13]

Originally Posted by cadd

I would guess around 35mpg from the info he provided.

I would, too. But I don't like guessing about things that are easy to measure.

(If nothing else, mpg will rule our someone having put a bunch of marbles or rocks in the gas tank).

[RPS13]

In my automotive experience as an automotive backyard worker and online research made me conclude that SeaFoam does nothing other than dumping baby oil into your engine.
I used lucas fuel cleaner and it fixed a non-firing injector lol, But this is carbs and; although, I still dumped a bottle in my tank for fun lol.

[RPS13]

*Stupid newb input * but maybe there isn't stock jets inside?

[Brother Michigan]

Seafoam is good stuff when used correctly. It is not a miracle cure-all and 99% of the time is more of a maintenance product, but if you have some nasty old varnished up carbs, it will clean them out given the proper amount of time.

[Ghostt]

Okay Seafoam is not the cure all, it's works great for preventative maintenance/upkeep item, add to tank to keep things flowing, but once they stop, it will not unclog jets, fuel circuits, wore float needle valve, etc....

Only a proper and meticulous carburetor cleaning and rebuild is the only answer.

[InvisiBill]

Originally Posted by dcj13

I would, too. But I don't like guessing about things that are easy to measure.

(If nothing else, mpg will rule our someone having put a bunch of marbles or rocks in the gas tank).

This. OP needs to state his actual miles per gallon, calculated from the miles and gallons between two fill-ups. "Miles per fill-up" and "the tank is full" are not precise amounts, and those variable values could produce numbers that sound very low but actually don't indicate any problem with how it's running.

I'm saying this because I've seen it happen before, and a number of people wasted a bunch of time trying to fix a non-existent problem because the poster didn't specify actual numbers.

[silverchair19]

my friend found the needle valve stuck and changed my oil ....he also found the air inlet for the gas tank was slightly pinched.
hecalso recommended changing to a different sizes front and rear sprocket for better gas mileage. has anyone done this?
i have a 2007 kawasaki 250r can someone recommend or give me a link to a set of sprockets that would help me to achieve this ?
thanks everyone for your help !!

[silverchair19]

and between 2 tanks i was getting about 27-28 mpg...i just picked her up and drove her home she feels great and has a full tank now. so i will update when i run the tank dry and tell you guys what my mpg is.

[EMSRacer07]

15 tooth front sprocket will help a lot. It can be done very easily on a pregen. The rear sprocket is a bit more work bc the wheel has to be removed but the front can be done really fast. A lot of guys on here switch to the 15 tooth sprocket for gas mileage and keeping the rpms lower on the freeway

[Hero Danny]

I thought switching the sprockets had no affect on gas mileage...

[Ghostt]

I personally have gone +1 on the front, which is the most one can do, and probably for good reason, if you gear it too low, then you'll be lugging the engine, it's not a car, it's a bike, and bike loves revs, the power band on the Ninjette starts to wake up at about 8k, no worries because Kawasaki made it to run like this.

Any more questions feel free to ask.

[Ghostt]

Originally Posted by Hero Danny

I thought switching the sprockets had no affect on gas mileage...

Very true, it doesn't effect the mileage that much, just lowers the RPMs a little and doesn't work the engine that hard, the most noticeable difference is it does spread the gear ratios out a bit.

Personally I did +1/-2 which at 70mph equals 7.5k RPMs, at 75mph, equals 8k which is just at the lower of the power band.

[silverchair19]

thanks ! nice to know!

[Ghostt]

Originally Posted by silverchair19

thanks ! nice to know!

If your commuting is mostly on the highway, then gear down might be the answer, if it mostly in the city with a lot of stop and go, then stick to stock.

You could try changing the front sprocket, it's easy and inexpensive to do, if you like it fine, if not change it back.

[silverchair19]

Originally Posted by Ghostt

If your commuting is mostly on the highway, then gear down might be the answer, if it mostly in the city with a lot of stop and go, then stick to stock.

You could try changing the front sprocket, it's easy and inexpensive to do, if you like it fine, if not change it back.

i just might try it i drive about 120 highway miles a week

[Ghostt]

Originally Posted by silverchair19

i just might try it i drive about 120 highway miles a week

Keep in mind with lower gearing, it will also change all the gears as well, it does spread them out a little.

[Motofool]

Originally Posted by silverchair19

my friend found the needle valve stuck and changed my oil ....he also found the air inlet for the gas tank was slightly pinched.

Could you explain those a little more?

[silverchair19]

Originally Posted by Motofool

Could you explain those a little more?

wish i could this is what he told me im new to motorcycles ive only owned one for a month now. ive got alot to learn thats alot of reason i joined this forum to get answers to my questions and learn as much as possible.

[ninjunk]

he probably means the float needle in the carb was leaking/hanging and that the line coming off the nipple out the back of the tank was pinched.

i hope you fixed the problem, but i'll add (since nobody clearly stated it)

its very common for people to put bolts in the side of the fairing on the gas tank that causes it to puncture the tank.

you will see run marks under those bolt holes, hidden beneath the fairing, if this has been done.

if you can see tool marks on the screws that hold the fairing to the tank, its probably worth popping it off and checking to make sure you don't have a small leak... although i'm guessing it would be pretty hard to miss, smell and possibly gas on your legs would be a dead giveaway.

[spooph]

Along with all of this, I believe Ghost mentioned it - these engines like to rev. If you are accelerating, make sure to be higher in the revs. Above 6K at least, then downshift when you're at speed. You're not going to hurt the bike, and you're gas mileage will improve up to a point.

I get 70mpg on average riding with heavy acceleration in the first 3 gears, then shift to top gear to cruise - this means you have to downshift 2 or 3 times when needing acceleration and if you're not comfortable with shifting that fast when you need the power, maybe not the best idea, but something to think about.