Apalling Fuel Economy - Fzr250

[Magua]

I spent $11 and filled the tank right up and at 100k's I gave the killswitch a flick in preperation to start the bike and I hear the fast clicking of the fuel pump or whatever. Just over 100k's on the maintank? Come on, I know it's an '88 but that's pathetic. If the bike is running rich, can I adjust this anyway without taking out the carbs as I have no experiance in this area, cracked seals and rusted fairing screws with no thread :devil2: .

[JohnBoy]

i had a 1990 yam 3LN 250 once and it also went through gas like it was going out of fashion. i only got about 120 km on the main tank. i had the shimms replaced, carbs balanced and rejetted but didnt really achieve much.
but fuck did it go, had it off the clock a couple of times!
i never really got to the bottom cause a young girl tryed to torpedo me with her push bike ending in a write off.
happy hunting dude

[Stevo]

I get 160 AT LEAST before going onto reserve. Before I re geared it I used to struggle to get to 150 total!!

Wouldn't be much fun in town the way I have it geared at the moment but 98% of my running is open road like..............

What size sprocket is on the back? Should be a 17 on the front most likely. I found almost a direct relationship (18% better economy by gearing up 18%). I was only expecting 10 - 12 so this might be an option.

PS: Ya shouldn't have to count all those teeth on the back sprocket........... it should be stamped onto it and say 50 something........

[aff-man]

well work it out. On the zxr250 that had a like 14l tank (i think) i could get about 220 (or a bit more) km . 100 seems awfully low even if it is running rich :eek:

[StoneChucker]

Man with very low fuel milage, probably got leak in petrol tank

[SPman]

Frances used to get about 160k before reserve on her 87 FZR. Same consumption as the FZR 750

[Posh Tourer :P]

Also is your exhaust standard? Milky's ZXR exhaust/mufler mods got him from 200 to 250kms per tank (more back pressure/more restricted)

[riffer]

Frances used to get about 160k before reserve on her 87 FZR. Same consumption as the FZR 750
Ouch. I used to get 200-210 before reserve on my FZR750. After upping the main jets from 80/82.5 to 102.5/105's I now get about 180kms before reserve, and I like to use full throttle in the first couple gears.

Check your choke butterflies aren't stuck on. My one had the idle mixture screws way down and the choke stuck partway on when I got it. Used to get 145-150 out of a tank, sorting the carbs made a huge difference.

If I were you, I'd replace the air filter, then plugs, then adjust the idle mixture and balance the carbs, then check its not too undergeared (back/front sprocket like Stevo said). After that, check the fuel lines. Is there a petrol smell about the bike? My bike has a bit of a leak where the reserve hose hits the petcock. It's caused by the rubber o-rings getting corroded by the toluene in unleaded petrol. It could be doing the same to you as well, as your bikes similar vintage.

If all that is okay, maybe you should have a little think about how you are riding. If you are using full throttle a lot, then you use lots of gas.

Try the other stuff first...

[FROSTY]

It hink celtic has it nailed, If ya spend a lot of time with the throttle wound wide open then for sure you're gonna use a shit load of gas
My zxr 400 only gets about 150km from a tank of gas but its always on full throttle. so you can see how it can make a huge difference in fuel economy

[Magua]

I'm going to eventually get to the air and fuel filters. Money is restrictive. But today as I left school I walked over to my bike in the pouring rain and saw what looked to be either petrol or oil on the ground. It washed away fairly easily so I'm aussuming it was petrol. Who can take a look at my leak for me? Holeshot/cyclespot I'm assuming would charge a bit while they fiddle around looking?

[Magua]

Ok I think I've got a 45 tooth sprocket on the rear. I've added some pictures of the carbs, you can see what looks to be a liquid from the carbs in two of the pictures, possible source of the leak? Can anyone point out the idle mixture screws?

[Big Dog]

I spent $11 and filled the tank .....
Litres not dollars dude! ffs that could be 9.1l of 91 or 8.5l of 96 at current prices....

If so and it may just be your wrist action getting you in trouble.

Next Q are you turning of the taps at night?

[Big Dog]

Note my fuel consumption is approx .1 of a litre per km 10l/100km but I stress a bike quite a bit, about the same as a normal rider w/ pillion.

[Magua]

I don't stress the bike all the time, of course I give it a bit of twist everynow and then but I rarely climb over 8k rpm. No I don't turn the fuel tap off at night, should I?

[Magua]

What size sprocket is on the back? Should be a 17 on the front most likely. I found almost a direct relationship (18% better economy by gearing up 18%). I was only expecting 10 - 12 so this might be an option.

I think I've got a 45 on the rear, I don't have the tools to open up the bike and have a look at the front.

[Stevo]

I think you possibly have a 57 on the rear at a guess the same as what mine had. I can count 19 teeth in the picture on approx 1/3 of the sprocket but I could be mistaken.
Another way of putting it. My bike used to be doing umm 9000 odd revs at 100kph and is now doing about 8000. AND it is MUCH NICER to ride now that it is not ringing its nuts off esp when cruising along at 120 or so (Oops I mean 100kph for long periods) - Yeah right.

Just today I have replaced my front sprocket and chain as the old front sprocket was badly rooted. Chain was not so bad but I changed it seeing as not so old back sprocket and new front one.

If you cruise round town and don't ride open roads so much then I would prob not bother changing the gearing. But it was a thought? What sort of riding do you do?

[Magua]

Just around town, possibly into the city in the next few months from Birkenhead to Fanshaw. It's a nice dry day, well so far, so I'll see if I can spot any obvious leaks, overwise I'll just continue with my efforts to replace the filters and see if there is any difference.

[Big Dog]

I don't stress the bike all the time, of course I give it a bit of twist everynow and then but I rarely climb over 8k rpm. No I don't turn the fuel tap off at night, should I?
I do stress the bike just by being on it lol.

But seriously try turning it off every night and see if it makes a positive change to your consumption, especially if you are talking 80's early 90's 250cc with carbs.

Alternatively your next best bet for a leak is a faulty tap.

[Big Dog]

Just a thought, grab a tissue and the tap in the same hand, give it a wiggle if the tissue is now wet you will be leaking over night, repeat in the closed position, if it still leaks replace the tap.

Leaking fuel is often hard to trace due to the tendancy to evaporate unless it is raining. From your description earlier I would not smoke to close to it before you get a chance to check it out.

[Magua]

Fuel tap doesn't seem to be the source of a leak, but I'll keep it off overnight from now on.

[Stevo]

Hi Magua. Just wondering how you got on with both the fuel consumption, and the throttle problems?

[Magua]

I've been rather lazy and have been spending my money on everything but my bike so I've gotten no where yet. I went in and talked to a mechanic and he told me either my carbs are fucked or it could be something simple like the air/fuel filters.

[Magua]

I think you possibly have a 57 on the rear at a guess the same as what mine had. I can count 19 teeth in the picture on approx 1/3 of the sprocket but I could be mistaken

If you look closely it says "C 45" under that symbol. 45 Tooth?

[Stevo]

Ok. For whatever reason I don't think that C45 means that. I just recounted your teeth on the pic of your sprocket. And I get 18 or 19 teeth between the first and third nuts which is 1/3 of the sprocket. When I looked at getting mine I was told that they come in the following: 46,47,51,52,54-57.

Maybe I should have only gone to the 51 cos 57 to 47 teeth on the rear sprocket is a massive change in the gearing!!

Tis good though only for the fact that mostly I am on the open road and so not stopping and starting too much

[The Pastor]

Mines (zxr 250) got even worse fuel economy. It ran out on me today on the north western (in rush hour traffic,) and i put $13 bucks in, that was about 8am. After about maybe 2 hrs of riding (not all at once) it was empty! so my frankie put in another 10 bucks this evening :( :( $23 bucks a day, thats worse than a hummer.

[marty]

a blocked air filter can cause excessive consumption, that's an easy fix/check. if it's fueling that much though, it would be running like crap, although it would be easy to start from cold.

now 2 hours of riding is gonna eat $13 gas (that is only 10 litres), even/especiallyu around town - try riding for 2 hours on the open road on $13 gas - that's getting into 45mpg range

[The Pastor]

13 bucks, filled her up....

[Juan]

Not sure on anything but miles to the gallon.... sorry, but my Brutale is crap on fuel, full tank does about 90 miles.... FZ1 will do 160 at least....

how much per litre is your fuel?? ours over here is 90 pence per/L

[marty]

90p/litre = $2.41 on today's rate. our gas is about $1.25 (.46p)/litre for 96 at the moment.

i get about 200k out of the TL, with a mix of heavy open road and round town riding.

[Juan]

90p/litre = $2.41 on today's rate. our gas is about $1.25 (.46p)/litre for 96 at the moment.


Feck :eek: where the feck do the uk/iom gov get the prices from over here, Brutale is deffo coming with me :niceone:

[The Pastor]

Where is the fuel tap? Can some one tell me and maybe take a picture of it? my bikes a 91 zxr 250c....

[The Pastor]

bump

I nead to know aye....

[Magua]

a blocked air filter can cause excessive consumption, that's an easy fix/check. if it's fueling that much though, it would be running like crap, although it would be easy to start from cold.

Sounds exactly like the problem, it really gurgles like it has too much petrol in the engine. I just can't get past the rustry screws damnit to even have a look! :brick:

[Magua]

I'll show you Scott. How can you miss it? It's visible in your trademe photos.

[Magua]

There we go.

[The Pastor]

oooooh thats the fuel tap, I was calling that the reserve tank switch