Put the open bottle under the carb and drain the float? Not the fastest but only needs a screwdriver.

I usually carry a clear small plastic tubing about 4 feet long to siphon gas out of the tank into the MSR bottle.

You're absolutely right and it's called..........wait for it......... a "JIGGLE SYPHON"! About a fiver off ebay

Anti Static Jiggle Fluid Diesel Fuel Siphon Syphon on eBay (end time 04-Aug-10 16:11:42 BST)

Jiggle syphon
 

OK, this is a bit obscure, but the jiggle pipe in the above post is very similar to a piece of kit used by environmental consultants to sample water from boreholes. The most common supplier is a company called 'waterra' (I dont work for them!)

A foot valve costs a couple quid and you can get rolls and rolls of tubing for pounds. If you know of anyone who works for the water industry or an environmental consultant, it wouldnt hurt to ask if they have a valve and some tubing going spare.

.....said it was a bit obscure!

I just use the good old tried and Tested Mk1
Tube and suck till you see it coming I have a Coleman multi fuel.

KISS = Keep It Simple Stupid

Try something like this?
Add a T joint to the fuel line and a on/off cock. Just make sure to close it securely before riding, or you may have gasoline leaking onto a hot engine...

http://img02.naturum.ne.jp/usr/rider...m/IMG_3591.JPG

http://img02.naturum.ne.jp/usr/rider...m/IMG_3563.JPG

We used the MSR Dragonfly stove on our recent trip, the small fuel bottle fits under the seat on my bike or we have a holder and it clips onto the top of the luggage when we need to get to it to fill at a garage.
Small neck on the bottle no problem, just get a used soft drink (coke) bottle, cut the bottom off to desired length and remove the lid and hey presto a funnel then you throw it away when used.

T-piece and fuel tap works on all carb bikes. Even those with vaccum taps.

If you have access, you can just pull the pipe off the tap or carb.

If all else fails, just take 1-2m of clear fuel line and syphon it out of the tank. You can control the flow just by raising the height of the hose. EASY !! (especially if you've ever filled bottles from your homebrew kit lol)

Those quick release unions tend to start weeping/leaking after a while. The one I had had did anyway.

I just went down the local boat shop and bought a squeeze type inline fuel primer and a metre of fuel line. Why didn't I do it sooner????

This suggestion came from the audience at the HU Australia meeting earlier this year, thanks heaps

Glen

Cranky pump
 

I've been using the cranky pump from aerostitch for a while and it works great. It has a metal tip on one end to make sure that it gets to the gas in the tank. Also only pumps when cranking so it's easy to stop when you have the fuel you need. I also like that I can use it in reverse and put the unused fuel back in the tank.