I was riding home this evening when I hit what I guess was the famed "bank holiday traffic" about 5 mins from home. I sat in traffic for about 10 minutes when the temp light came on. I couldnt hear the radiator fan coming on because of the other traffic and the rain (so I cant tell if it came on at all). Was debating just turning engine off and letting it cool but I was about 5 metres from the traffic lights that was holding up the traffic.

Then the bike vented coolant in a big plume of white smoke over my leg from the right hand side of the bike upper engine area. I turned it all off the engine and stuck the hazards on and pushed it to the pavement and had a look at it.

As far as I can tell the coolant expansion chamber (usually only about an inch of coolant visable) was full (1cm space from top!) due to it expanding as it heated. Seems as it had no where to go it blew out one of the clips on the tubing around the top of the engine (to the left of the spark plug looking from the right hand side) and vented the excess coolant onto me. Due to being wet and wearing thick bellstaff overtrousers I didnt get burned but it was pretty large amount of smoke and I certainly felt the power behind it.


That didnt strike me as a particularly safe way to vent the coolant, but its clearly not supposed to do that :P Pushing it home, Ive since toweled off all the excess coolant and the bikes sitting outside with its cover on. Starts ok and the temp warning no longer comes on.

Ive since reattached the blown rubber tubing and clamped the metal clamp back in place. Im going to drain the coolant tomorrow (seeing as it is still too high dispite me not putting any more in since.. well ever as its just done routinely with its services). Im going to attempt to book it it for its MOT for next week as well, (due on the 2nd) but is there anything else I should be aware of/look at, or any potential damage that may have occoured as a result?

cheers