A three-quarter mile workout

[Fazbaz]

Fazerider explained the air gap mod...... "When I had the tank off for repair a few years back I drilled a hole in the side of the filler tube. Air escapes there as the level rises up beyond the bottom of the tube so "overfilling" the tank doesn't take long... can usually get 19 litres in."

Basically when you look in the filler neck you'll see a tiny wee hole on the RHS of the neck. I opened this up from 1mm diameter to about 14mm with a dremely type thing. On a Foxeye tank you can fill about 24 litres into the tank giving massive mileage range.

Baz 

[Fazerider]

"....a hole drilled through the filler neck to allow filling below the bottom of the tube...."


Sorry, i'm probably being a bit slow here, but can you explain this a bit more please?  :crazy

Oops... no, you weren't being slow... I was. :o
The description would have made much more sense had I written "above" rather than "below"!

[darrsi]

[quote author=darrsi link=topic=6132.msg57016#msg57016 date=1360404643]


"....a hole drilled through the filler neck to allow filling below the bottom of the tube...."


Sorry, i'm probably being a bit slow here, but can you explain this a bit more please?  :crazy

Oops... no, you weren't being slow... I was. :o
The description would have made much more sense had I written "above" rather than "below"!
[/quote]


So are you saying you can gain about a litre of space then just by opening that little hole up?

[Fazerider]

So are you saying you can gain about a litre of space then just by opening that little hole up?

Yes. (Unless you're patient enough to keep filling very slowly as the air bleeds though the tiny hole.)
I saved the job for when needed to clean the tank out anyway for a repair on a rust hole. I didn't want swarf clogging the filter and had concerns about the fire/explosion risk.
I guess braver people than me might figure a way to catch the filings with a magnet and do the cutting with a full tank... theory being that the greater the air space available the larger the potential bang if the concentration of petrol vapour gets low enough. For the same reason it'd be safer to do it on a hot day rather than a cold one.
I'm sure of the science, but am also a coward... so made certain the tank was vapour free instead. :lol