Thunderbird 900 - Fuel Tap Question...

Discussion in 'Thunderbird' started by Ian Suggett, Sep 8, 2017.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. Ian Suggett

    Ian Suggett Member

    Aug 22, 2017
    27
    13
    Durham
    Hi All

    Whilst reading the owners handbook for my new Thunderbird 900 I noticed that it states that the fuel tap should be set to 'Off' when the bike is not being used.

    Can anyone tell me if this is something I should be doing? Will it cause a problem if I leave it 'On' between rides?

    I've never owned a bike with a fuel tap before so I have no experience of this.

    Thanks in advance...
     
  2. stevethegoolie

    stevethegoolie Elite Member

    Oct 16, 2014
    2,452
    800
    East Riding of Yorkshire
    If you leave the petrol tap switched on, then the only thing preventing a tankful of the finest unleaded petroleum ending up either on the floor or in the bike's engine is the efficiency of the float and its valve in the carburettor. A bit of muck or gunge preventing the needle valve closing properly, or indeed a punctured float (unlikely and would lead to poor running anyway) could easily cause a sump full of petroil - which is fine on a 2 stroke (well, not really - not a sump full - but you see what I mean) but highly detrimental to a 4 stroke engine.
    Thankfully it never happened to me, back in days of yore before vacuum fuel taps and fuel injection, but my mate's early CB750 suffered that fate overnight, which cost him an oil change and a day off work:mad:. Good job he didn't smoke!!!!:eek:
     
  3. crispey

    crispey crispey creme de la creme

    Nov 6, 2014
    7,194
    1,000
    Uk
    Just turn it off!! How long will it take?
     
    • Agree Agree x 1
  4. Sir Trev

    Sir Trev Senior Member

    May 27, 2017
    652
    193
    Buckinghamshire
    Just remember to turn it back on again before you ride off. When I was a lot younger my first H***a had a fuel tap and many's the time I sputtered to a stop after half a mile, swearing, turning it on and kicking the thing over several times to draw enough fuel through to start it again. Good job it was a weedy little 2-smoke 100cc. Got quite good at checking the tap on the move as soon as it coughed though :rolleyes:.
     
    • Like Like x 1
    • Agree Agree x 1
  5. Havit

    Havit Admin
    Staff Member Subscriber

    Jul 17, 2015
    9,567
    1,000
    Kent
    #5 Havit, Sep 23, 2017
    Last edited: Sep 24, 2017
    Was told to turn off and run engine until carbs are empty buy a good bike mechanic who works on the triple engines. Even if your riding the next day .
     
    • Agree Agree x 1
  6. Sir Trev

    Sir Trev Senior Member

    May 27, 2017
    652
    193
    Buckinghamshire
    I can imagine that would be a good move if you were going to lay the bike up for a while, assuming it was a faff or you were unaware of how to drain a float bowl. Got no idea of how that sort of thing works with current FI throttle bodies so I'll, er, defer to others on that one and not worry.
     
  7. Havit

    Havit Admin
    Staff Member Subscriber

    Jul 17, 2015
    9,567
    1,000
    Kent
    The reason sir Trev apparently is to do with these bikes are prone to the floats sticking and filling the air box and engine oil with petrol. It might never happen . It's only happened to me once. So it's more of a precaution. I normally turn the tap off just before I get home so they are near empty when I get home. It only takes a bit of crap to get into the carb to cause this kind of issue. Rusty tank for example .
     
    • Agree Agree x 3
Loading...

Share This Page