As above, they hold quite a bit of fuel, there is also one bolt holdin the filter to bracket which often breaks, the captive nut, so will most likely have to effect a repair here ?, but very easy to do.
MIne surged like buggery after filter, just let it run for 5 minutes it was up/down/up/down, mostly up to around 2500rpm, but settled down after this.
The difference on the road was amazing though, far more bottom end than before!!, so well worth doing.
The filter is "HANDED" so only goes in one way with an arrow so you can't get it wrong as bolts are a different size and will not fit each other, don't lose the copper washers and make sure the sealing faces are nice and clean.
tabetha
ps and don't get petrol in your face it stings a lot(appartently!!)