Don't know if anyone else has this problem but I find it tricky to fill my Street Twin to the brim with fuel, without petrol squirting back out of the tank. For some reason unknown to me, Triumph have designed the tank so that when you open the cap you are presented with a very narrow opening, instead of a conveniently wide hole, in which to stick the nozzle. Do other bikes in the Classic range feature this daft design? I have never come across it on any other bike. This means I have to guess when fuel is nearing the top of the tank because I can't see what's going on. I like to fill it up, leaving as little air space as possible, so I have to gradually and slowly withdraw the nozzle. Sometimes I misjudge it and either fuel erupts out of the tank or the nozzle slips and I coat the bike with petrol. Even after 3 years of ownership I still find it a challenge every bloody time! Bloody stupid design!! And what the hell for?
But seriously. I tend to stick the nozzle an inch or 2 inside the tank and go flat out till the fuel hits the nozzle and the pump stops automatically, then withdraw the nozzle and trickle the last bit in.
Well,it's Sunday night and beers have been consumed. Attempting a sober answer for a moment, all I would say is I don't have a problem filling my Street Scrambler tank and I don't think they are that different. The Husaberg on the other hand has a weird shaped tank, plus I use a tank sock and filling takes feckin ages!
Check your owners manual I was told to stop filling 13mm/ 0.5" below the lower part of the neck. Prevents blow back from vents and burps. All vents need some air gaps to work properly and to account for fuel expansion from the engine heat.
A bit like Andy C, I hold the nozzle just below the bottom of the neck and fill up at about half speed untill the pump stops. I used to look at the pump, kind of by habit from cars, but after lifting the nozzle out as I looked around to the pump and spraying petrol everywhere including over the hot engine, I stopped doing that! Half expected a fireball.
I imagine thruxton 900 is similar and it is noticeably harder to brim without spilling fuel than any other bike I have owned due to the small opening making it impossible to see the fuel level with the pump nozzle in situ.
Petrol is very good at not igniting when spilt over hot engines and exhausts which is rather handy really. Needs a spark to do its bang-woof thing. Brake fluid on the other hand is very good at self-igniting when hot; in an accident it's more likely that spilt brake fluid ignites on the engine and then it's that flame that ignites the petrol vapour.
Tell that to the guy who’s new R3 burned to a cinder after fuel burped back off the baffle or whatever it is just below the filler hole and ran onto the engine. Ken.
OK, I should have been clearer. Petrol will not self ignite unless the temp is above 280C. It is very unusual for engines on road vehicles to get to this temperature. In my own tests (not scientific I know) the hottest I was able to get the downpipes/cat entry on my street scrambler was 202C
I've soaked the hot engine and exhaust on the Berg numerous times, due to the problematic filling, thankfully with no issues. What usually happens is the fuel evaporates rapidly into a dense cloud of vapour which can easily be ignited by a spark from the bike, static from your nylons, fag etc but the hot exhaust in itself isn't enough. I guess if your headers are glowing then maybe.
Blimey! The headers much have been ridiculously hot. As an aside I went to look at the temp at which brake fluid ignites and it's virtually identical to petrol. Perhaps my aged mind is failing me!
Not sure that the actual cause of ignition was determined in that case. Pretty sure the bike owner got paid out. Ken.