Tiger 800xc throttle cutting out

Discussion in 'Triumph Tigers' started by elbúho1k, Aug 19, 2021.

  1. elbúho1k

    elbúho1k n00b

    Joined:
    Jul 24, 2019
    Oddometer:
    4
    Location:
    Colorado
    I have had a 2016 tiger 800xc since last year. I bought it with nearly 40k miles on the clock and have only put a few thousand on it since that time. I would have ridden it more but my health this last year was not great and didn't feel like it. I also had to sort through some mechanical issues just after buying it (The cam chain tensioner failed on one of my first rides. It jumped several teeth and nearly grenaded. I had/have a service contract on the bike but my dad and I decided to fix it ourselves. We installed an aftermarket manual tensioner in the process of doing so).

    The bike has always had a bit of jerky throttle off idle as well as a bit of a flat spot in the powerband between 3.5 and 5k rpm. I have gotten used to those nuances, but recently I discovered something else. If the bike is held at the same rpm (Within the range of appoximately 3.5 to 5k rpm only in my experience) for more than a few seconds, it begins to sputter quite badly. If I roll into the throttle very gently after this sputtering has begun, it very briefly cuts out almost completely before picking back up again, almost as if I had quickly chopped the throttle closed.

    I replaced the plugs even though they looked perfectly fine to me and I also installed a new k&n air filter with no effect.

    If anyone could offer their opinion I would greatly appreciate it. I have looked for information regarding this problem but have thus far come up empty handed. Many thanks in advance.
    #1
  2. Raconnol

    Raconnol Long timer

    Joined:
    Feb 23, 2012
    Oddometer:
    1,273
    Location:
    Victoria, BC
    Check the spark plug wires for wear and or shorting out.
    Also, confirm all your ground and power connections are 100% from the battery to the frame and the master fuse under the battery.
    This sounds a lot like a ground issue, (or loose connection) but that is just a guess from past experience on other bikes.

    Under the battery, there is a 30amp master fuse. IF the drain hole on the bottom of the plastic "battery box" gets plugged, water can collect around the master fuse and funky crap can happen until the fuse finally blows.

    Some people do the master fuse mod to move the fuse to the top of the battery.

    Rick
    #2
  3. AloneInTheHills

    AloneInTheHills Been here awhile

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    I'd make sure you aren't pinching or kinking the fuel line under the tank. Did it sit with fuel for a long time - if so it may have varnished up the injectors. If it's not that I'd check that all the throttle body boots are seated and tight and check for any cracked or disconnected lines on the SAI, purge, airbox, etc. It could also be something in the throttle position sensor.

    If you ride around up in the 6-7k RPM range does it run okay?
    #3
  4. elbúho1k

    elbúho1k n00b

    Joined:
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    I will look into that within the next day or two when I have time. Thank you for the input.
    #4
  5. elbúho1k

    elbúho1k n00b

    Joined:
    Jul 24, 2019
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    Location:
    Colorado
    It did sit with fuel for the entirety of winter...but, if i remember correctly, that was with stabil. This all started spontaneously rather than after I had worked on the bike and messed with the hoses, so I don't know how the fuel line would have become kinked. It's a thought, though. I'll strip it down and check to make sure all of the hoses are in order and that the fuel line is ok.

    The interesting thing is that this only occurs under light load and steady throttleand only in that particular section of the tach. If I give it the beans it's fine.
    #5
  6. AloneInTheHills

    AloneInTheHills Been here awhile

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    Apr 23, 2019
    Oddometer:
    875
    Location:
    Nevada, USA / SW NH
    If it can handle high RPM the fuel pump and hose are probably good. You can reset the ecu fuel/air metering by starting the bike (don't touch the throttle), run until the fan comes on and then run for 12 minutes after.

    At high RPM an air leak is masked be because it wants all the air it can get. If it were electrical you'd probably throw a code at high rpm. It could still be injector partially clogged too.

    Only other thought is oil vapor can foul MAP & MAF sensors or an O2 sensor could be fouled, but haven't seen much of that.
    #6