Once the tank gets into bottom half of fuel every now and again starts to miss.

[Alex Wong]

Well, as i explained above, I will fill tank up and be sweet(btw its a 2004 gn250) and when the tank starts to get below 1/2 it starts to miss, which is frankly, annoying.
I was thinking the tank may need to be drained and cleaned because when i first started riding(learning from scratch) i had a few issues with running the tank dry. So maybe when the fuel gets low all the flakes get all amongst it?

Opinions past experiences etc are highly welcome and appreciated.

Choice.

[george formby]

Well, as i explained above, I will fill tank up and be sweet(btw its a 2004 gn250) and when the tank starts to get below 1/2 it starts to miss, which is frankly, annoying.
I was thinking the tank may need to be drained and cleaned because when i first started riding(learning from scratch) i had a few issues with running the tank dry. So maybe when the fuel gets low all the flakes get all amongst it?

Opinions past experiences etc are highly welcome and appreciated.

Choice.

Put an inline fuel filter between the tank & carburetor if one is not already fitted. Crap in the tank could be blocking the outlet from the tank as the fuel gets low but I have only experienced that when getting close to reserve. If your sure it is crap, pull the tank off when your fuel is low, give it a swirl around & pour the petrol through a fine strainer. Put petrol back in & repeat a few times. It won't get everything out but it is an easy way to see how bad it is. Put fresh petrol in the tank when you replace it, the old stuff will have all sorts of bits in you cannot see.

I would be checking my carbies too for foreign bodies.

[nadroj]

Tie a magnet to a bit of wire & dangle it around inside the tank & see what it picks up. I once had one permanantly fitted on a piece of wire connected to the fuel cap inner screws. Cleaned it every tank full of any crap.

[george formby]

Tie a magnet to a bit of wire & dangle it around inside the tank & see what it picks up. I once had one permanantly fitted on a piece of wire connected to the fuel cap inner screws. Cleaned it every tank full of any crap.

Thats clever.

[CookMySock]

It should already have a fuel filter fitted. Sounds like it needs replacing.

[Wannabiker]

When it gets below 1/2 and starts to miss it is time to switch to reserve....:innocent:

[Alex Wong]

Cheers will give the magnet a hoon and see if it picks anything up :)
Failing that i will try option B

[Laava]

Some good advice there Alex. Also you have a very user friendly bike for maintenance so it should be a doddle. Personally, I would do all those things amd then you have eliminated any chances. If the inside of the tank is rust free, then I see no need to fit an inline filter, assuming the gauze one in the tap is fine. If you are going to struggle with any of this, give me a yodel as I am in town and I will give you a hand. Al 021 0796444

[Flip]

Blocked fuel filter or blocked fuel tank breather.

The rust should be non magnetic.

If the bottom of the tank is a bit rusty we used to take the tank and the fittings out and throw in a handfull of nuts then pay your younger brother to swirl them around for 20 min. Than wash the tank out with petrol, replace the fittings and replace the tank.

[gunrunner]

You could empty and clean out tank , change the fuel filter as could be full of shit .
Or so the carb could do with the shotgun technique .. could be a build up of shit in there , is it running rich at all ?

[Alex Wong]

Thanks for the all the great feedback, got some time and looked at the manual...find out theres a sediment cup in GN's. Took it out, full of shit, cleaned it, good as gold now :)
Well, i guess i'll find out when i go for a decent ride, but running much nicer.
Turns out workshop manuals and reading get you somewhere..

[willytheekid]

Blocked fuel filter or blocked fuel tank breather.

The rust should be non magnetic.

If the bottom of the tank is a bit rusty we used to take the tank and the fittings out and throw in a handfull of nuts then pay your younger brother to swirl them around for 20 min. Than wash the tank out with petrol, replace the fittings and replace the tank.

Yup! +1 , Flips nailed it.
I had "similar" probs with the guzzi's fuel flow-it was either not supplying enough petrol or flowing to fast for the Keihin's and flooding the carbs.
Solution was as Flip stated-flushed and cleaned the tank and rebuilt the fuel cap (to clean the breather hole), rebuilt the electronic fuel taps and put new fuel filters on that supplied the correct "fuel flow".
Went through 3 sets of filters till I got the correct rate of fuel flow for the carbs....been perfect ever since :)

[Hawkeye]

Turns out workshop manuals and reading get you somewhere.


Nah!!! Highly overrated.

[Alex Wong]

Hahaha, true. But to be honest most problems i've had with my GN are mistakes or ignorance on my behalf. So it does have alot of information i dont have.

Choice, glad to hear you sorted it out, hopefully i wont have to do that, but we will see if i come crawling back to this post haha...