hi i was wondering if anyone could help i have a dtr125 iv had the bike for a few months now and it all runs ok i think the head gasket has gone as the rear expansion tank bubbles and leaks and the rad needs topping up all the time but what i would like help with is at the front of the cylinder there is black runny stuff coming out and i cant tell if its coming from the base gasket on the cylinder or if its coming out of the exhuast iv taken the exhuast off today and there was a bit of the black stuff in there so do you think thats were its coming from or would this happen if your cylinder base gasket has gone thanks for any help Gary

hi i ment to say it only happens when the bike is running thanks

It's most likely the exhaust gasket but hey...cant say for sure. you shouldnt be riding it with the head gasket leaking....you could warp the head!

thanks Airhead thats what i thought as the person i bought it off had panited the exaust before selling it and not replaced the gasket. iv changed haed gaskets before but only on air cooled bikes is it any different on a liquid cooded other than draining the cooling system first iv got the manual and a torque wrench is there any hints or tips for changing it thanks Gary

Its a tad more awkward than an aircooled one Gary, but you're on the right tracks with draining the coolant first.

buy a genuine yamaha gasket or an 'Athena' brand one, they are rubber coated and far better than the cheap pattern all metal ones.

yes use a torque wrench but theres a few of the head nuts that you will find nigh impossible to get a socket on so you'll have to guestimate these with a ring spanner