Good day all

I have a Bandit (GSF) 1250. Dropped it and damaged the radiator. The radiator was bent, but it still worked.

Bought a new, pirate radiator on E Bay. A fellow who's better with his hands than I am fitted it for me. Filled it with the correct kind and quantity of fluid. The bike starts and runs, but the radiator stays ice cold. Ride the bike, get the engine to full temp, fan switches on... but the radiator itself stays cold.

I doubt it's anything to do with the thermostat, because the cooling system worked normally with the old, bent radiator. The only thing that's changed is the radiator itself.

Any ideas? Is there something one is supposed to do to get a new radiator to get it to start flowing?

Obliged, Stan (Johannesburg, South Africa)

  • Welcome to the site. I don't know for sure, but would suggest since the engine itself gets up to temp and stays there without issue (neither too hot/too cold), I don't know there's an issue. I'd suggest to keep riding it and see if there are any adverse effects. The only thing which might keep it cold is if there was a plug in one of the two ends of the radiator which might have been mistakenly left behind when fitting it. Since the engine doesn't overheat, I'm thinking this is not an issue. Commented Mar 11, 2017 at 13:14
  • Thanks for this but the engine DOESN'T get to temp and stay without issue (neither too hot/too cold). There's no cooling AT ALL because the radiator remains ICE COLD, no matter how hot the engine gets. So it looks as if there may indeed be a plug that was left in there (can't imagine why they'd plug it in the first place?). I'll see if I can find one.
    – Stan Luntz
    Commented Mar 11, 2017 at 16:26
  • Sorry, I must have misunderstood something. You stated the engine gets up to full temperature, but you never said anything about overheating. This is what my comments were based on. I've seen where they put plugs in the new radiators to keep the crap out. I've also seen styrofoam get stuck in the inlets/outlets, which could be plugging something as well. Just some thoughts. Commented Mar 11, 2017 at 17:20

1 Answer 1


Assuming the radiator is topped up and coolant is flowing ok there may be an air lock in the cooling system. Whilst you're topping up the cooling system the bike will need rocking from side to side to help get rid of bubbles in the cooling system.. also there should be a bleed screw on the watertpump housing which must be opened to help bleed any trapped air from the system.

If all the above has been done and there's still an issue.. Take the radiator off and run some water through it.. you should be able to do this quite easily and water should flow. If not or it seems restricted the radiator may be blocked and should be replaced. Could also be a fault in its manufacture or perhaps one of its cooling ways has been damaged blocking it.


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