Poor fuel economy for my GN250

[CarlD]

It doesn't seem to make any sense to me but my GN250 has gone through about 9 litres of fuel in 4 days, is this even possible?
That works out to be about 73km from the 9 litres of petrol.
I'm new to motorbikes but surely something is seriously wrong here.
When I got it the last owner said to me that it was running a bit rich, so I adjusted the pilot screw down to 2 3/4 turns out from about 5, but havn't filled up since.
Surely it couldn't make that much of a difference.
There is nothing leaking from anywhere that I can tell.
Could anyone shine a bit of light on my problem?

Cheers
Carl

[Bad Biker]

Like you I am new to motorcycles.

I also have a GN250 and I am currently running 200km on a tank without the use of the reserve.

This allows for a bit of playing around and running the bike without clocking up km’s. The advise I was given is to not push it much over 200km and when the tank runs dry it will give no warning before the need to switch to the reserve tank it will just stop and you don’t want to be caught in an outside lane on the motorway.

I have just cooked a battery because the voltage regulator is not working correctly and currently charging 18 volts when running therefore putting to much charge in the battery.

Hope you get it sorted.

[Jantar]

It doesn't seem to make any sense to me but my GN250 has gone through about 9 litres of fuel in 4 days, is this even possible?
That works out to be about 73km from the 9 litres of petrol.
I'm new to motorbikes but surely something is seriously wrong here.
When I got it the last owner said to me that it was running a bit rich, so I adjusted the pilot screw down to 2 3/4 turns out from about 5, but havn't filled up since.
Surely it couldn't make that much of a difference.
There is nothing leaking from anywhere that I can tell.
Could anyone shine a bit of light on my problem?

Cheers
Carl

The pilot screw will have very little effect on fuel consumption as it is in the idle path of the carb. But 73 km per 9 l is only 8 km/l which would be far too rich for a 1000 cc bike, let alone a low powered 250. You can be sure that it isn't using that amount of fuel because of being too rich, or it would be so rich that it wouldn't even run.

You are losing fuel somewhere, and at quite a rate. Fill it up and park it up for a day with some newspaper underneath it. Any leak at that rate will discolour the paper and be quite obvious

[racefactory]

Check the float bowl overflow. Attach a small bottle to the overflow tube and go for a ride, lean the bike and ride like you normally would. Check the bottle to see if fuel has leaked into it. Could be that your float has a problem.

You are leaking fuel, no amount of jetting or running rich will cause that kind of fuel consumption.

[p.dath]

I had a problem once on a different bike, and it turned out to be the fuel tap. Took me a while to find it, as the fuel would travel down the outside of the petrol hose for a while.

Perhaps try getting a white paper towel, and wrap it around several of the fuel components, and see if it gets "wet" on any of them.

[CarlD]

Thanks guys, I will try a few if not all of your suggestions, probably this weekend mostly.
I'll let you know how I get on.

[Coolz]

Maybe someone is stealing your gas.Easy enough on older models to pull the line off the petcock,full a container then put the fuel line back on.

[Taz]

Reset your trip meter each time you fill up. Takes the guess work out of it and gives you an idea of range before next fill up. Also by dividing the distance you have travelled by the litres you have put in will give you your KM/L figure.
With a 28 litre tank on my bike I'm sometimes not sure how much fuel is in the tank when setting out for a ride. It'll do 500kms to reserve so a quick glance at the trip meter shows that "oh good I still have 350kms before I have to stop for gas "

[p.dath]

Reset your trip meter each time you fill up.

+1. I think most motorcyclists do this.

[Oblivion]

+1. I think most motorcyclists do this.

If they don't, I think that they should. Gives you something to fall back on if the electronic fuel metre fails.

[sleemanj]

While it wouldn't quite explain that high a usage, you should check that the choke is not stuck on. That and that the air filter is not horribly blocked.

[frogfeaturesFZR]

Can you turn off the fuel tap when you're not riding?
I'd guess you are not actually burning the fuel, more likely
You've got a leak.

[DrunkenMistake]

Can you turn off the fuel tap when you're not riding?
I'd guess you are not actually burning the fuel, more likely
You've got a leak.

Was going to say the same thing,
73km from the 9 litres of petrol.
Thats good economy! .. mind you I used to own a honda..

[frogfeaturesFZR]

Almost as good as my Mille !

[Ultrasonic2]

For interest sake my ZXR250 while commuting gets 19ks per L or for the same 9L i would travel 171km