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Hot GSXF - and not in a good way

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Bravus, Feb 27, 2008.

  1. My GSXF400 is from 1988 and uses the GSXR400 engine from that time. It's air/oil coiled, with no fan.

    There are major roadworks at the moment between home and work, and will be for the next couple of months. And it's Brisbane summer. The combination of these two facts is causing a lot of overheating in my bike. When it's stopped there's basically no cooling at all, and it's stopped a fair bit (even with splitting) at the moment. A couple of times it's been well into the red end of the temperature gauge.

    I guess a couple of questions:

    1. What kind of damage is likely to be done if it's overheating a couple of times a week? It's not boiling water or creating pressure, but it can't be good for it.

    2. Is there anything I can do? Might synthetic oil improve heat transfer and reduce friction and make it better? Or do I just have to try to find ways to go to work before or after rush hour to avoid the traffic?

  2. I ran a bike on the street with no fan (although it was watercooled). I kept moving (split etc) and simply turned the engine off if I was at a set of lights I knew to be a couple of minutes away from changing. Never had a problem with overheating, and that's a bike that glows red at the header when idling for 1 minute.
  3. Full synthetic would be a good start. Heating mineral oil will boil off the lighter compounds and cause it to thicken - this won't happen with synthetic. Switching the engine off if you know you're going to be sitting for a while would also be a good idea.
  4. Both great suggestions. Will work on those things.

    Of course, the real cure is a better bike!
  5. Any excuse will do. :LOL:
  6. Does the 400 run oil sprays on the piston like the 750?
    If so might also be an idea to keep an eye on the oil level (if not might explain why it gets hot easily).
  7. Perhaps even a little more oil in the engine would help as well, like 200ml or so over maximum. If there is more oil in the system it will run cooler, but dont do what an ex g/f of mine did and fill the engine right up to the top of the rocker cover ](*,)

    Also i dont know if turning the engine off when stopped will help all that much, keeping the oil circulating around the engine is going to keep the temperature uniform, switching off the engine means everything stops moving and can make the oil even hotter in certain parts of the engine.
  8. Yes, as said above, go with a full synthetic oil. f it's hot there, I'd look at a 20w-50 or even higher.
    Synthetics resist much higher temperatures before the lubricant film breaks down.
    If you're handy with electrics, a couple of small electric fans on your oil cooler would also work wonders, run them thorough a thermo switch like this one:
    Or just run them through a toggle switch. The fan could be from some bike with a very small radiator (the KLR's have a small fan), or small aftermarket auto fan, or even CPU fans.
    I would use oil temp to set it off, borrow a thermometer of some sort, and set the fans for 110 degrees c.
    I'd also be changing the oil every 3000kms on teh dot.

    Regards, Andrew.
  9. I'd also suggest synthetic... except... if its already done the damage, too much heat will warp your piston rings, and a fully synthetic is very thin and will get into more places, IE, being drawn into the piston firing area.
    However this seems to be fairly easy to diagnose... you'll be topping up your oil every week ;)

    And Def +1 on getting a fan of some sort, making a braket and mounting it, apparently davis-craig make a good automotive type fan. :)
  10. Sorry, that's wrong, a 40wt oil is a 40wt oil. Heat does not warp piston rings, it can cause them to lose tension ,but more likely, the piston will have scuffed the bores.
    It's an aircooled engine, it'll already have loose tolerances. And a synthetic being sucked into a combustion chamber tends to leave much less residue behind after it is burnt.

    Regards, Andrew.