I recently bought a 2006 DT125R with 6000 miles on the clock; the bike had a thorough service just before Christmas. I took the bike out today and covered about 50 miles on it, the bike was/is running fine but when I was about 10 miles from home the water temp light came on, so I pulled over and let the bike cool down for 15 mins and continued on my way. About 1 mile later the light came back on, so again I pulled over and let it cool down for 15 mins. Unfortunately this kept happening until I got back home.
I'm not the best at mechanically working on bikes but I'm willing to give it a go. I'd be grateful if anyone can point me in the right direction about what I should check and how I can get this problem resolved.
Have a look at the coolant expansion tank (behind lefthand number panel) and see if the level is low, if it is top it up and then if the bike overheats stop and look at it (dont take the cap of!!). If you see some bubbles in it your head gasket has gone.
You will have to remove the water pipe union from the top of the cylinder head.Its held on by three screws and has the top radiator pipe attached to it. Under this is the thermostat. To test it you will have to place it in a glass of water and heat it over a stove.Place a thermometer in the glass and the thermostat should open when it reaches ? degrees. Anyone got a manual handy for the temperature reading as i can't remember off hand. Anyhow, if it fails to open it will need replacing or run without one if your desperate for wheels for a short while
I just used a saucepan to test the one from my Runner tha other day, basically you want to see if it opens at all. Think the ped one opened just before boiling point - maybe 90c
Right, I removed the thermostatic valve today and tested it, it works fine unfortunatley so I guess it's the head gasket that's gone. Guess I'll off to buy more parts on moday.
Would it just be a new top end gasket set I need or would it be advisable to replace other things whilst I'm doing this?
