Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Cracked fuel tank

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by vahramh, Mar 22, 2014.

  1. Hi guys,

    My son had a highside last night... Looks like a fractured wrist (getting x-rayed now) and relatively minor damage to the bike - bent brake pedal, snapped right mirror and broken left (!) indicator. Also a dent on the fuel tank, which is what's concerning me most.

    According to him there was a pool of liquid on the ground - the rain had washed it away by the time I got there, but there was distinct smell of petrol on his boot. So, I suspect his fuel tank could have a crack.

    Is there a relatively easy way of checking if that's the case? We could fix the rest of the damage, but I've never replaced a fuel tank.

    The bike is a 1998 Honda Hornet 600.

  2. Replacing the tank would be very easy. The hardest part would be putting the fuel hoses on the right outlet.

    As a second point it the bike had been laid down the fuel could have just spilled out the overflow hose that is usually under the fill cap. The tank needs to breathe so as you take fuel out air goes in so it could have just come out this breather.
    You could take the tank off the bike and leave it sitting on some paper towel for a few days to see if its leaking?
    • Agree Agree x 2
  3. I'm betting it isn't split.

    Motorcycle tanks have a vent and petrol typically leaks from it when they have a lie down.

    [as noted above]

    Tanks are expensive
    • Agree Agree x 1
  4. Thanks guys, of course the overflow hose makes sense... I only saw the bike in the dark, going to pick it up now, will keep you updated
  5. You won the bet ibast :) The tank is fine, a few scratches and bent a little, but nothing serious.

    Of course we discovered some additional damage that we missed in the dark - snapped right footpeg (was still lying in the middle of the road), tear at the base of the radiator hose, exhaust pipe snapped - needs to be welded back to it's holder... However the one I'm worried about most is what looks like a crack on the cap on the right side of the crankshaft (see photo). The service manual refers to it as "timing hole cap", but I found a few photos on the internet referring to it as crankshaft hole cap, and I suspect the latter is correct.

    What I couldn't find is - info on what the cap is for. Is it only needed to keep dirt out (in which case I wouldn't worry about it much), or is there any pressure / oil / whatever inside it that requires the cap to be perfectly sealed?

    Any help with that info would be greatly timing hole cap. appreciated!
  6. I'm a bit late to the party, but here's my 2c worth.

    As others have pointed out, most bikes will dribble fuel if they are having a bit of a lie down. Bikes with carbies can not only dribble out the tank breather/overflow, but also out the carb bowl breather/overflow.



    Damn, beaten by the clock!

    I would pull that lug out and look at it carefully. If the crack extends all the way through, I would definately be replacing it, with a new o-ring if required. You don't want that failing and spewing out all the oil.
  7. The timing pickup will likely be "wet" and thus there is oil behind that cover.

    Replace it.
  8. Yeah, I guess no point risking it. I'm just concerned that the plug may not be easy to find! Will call Victorian Motorcycle Wreckers tomorrow - fingers crossed :)