Hi my DT 125 has started leaking coolant out of the overflow from the header tank where it runs down a hole in the frame just above the sidestand (i think), yet after running my bike the header tank isn't hugely over the middle mark and it is cool to the touch. The bike runs nice and cool for a while then because of the coolant leak it gradually heats up. Any suggestions? Thanks
I dont understand how a failing head gasket could cause coolant to leak out the frame, i have a new head gasket because i did a top end rebuild a week ago and the problem has only occured in the past few days. However i found the new head gasket to be...crap it flaked off paint or something and clogged up the coolant system a bit. Also since the rebuild my bike has a rattle, sounds like it should be the small end bearings as thats where the sound comes from, but it cant be because i replaced them, the sound stays with revs and it sounds too high up (sounds like it originates in the middle-lower of the barrel) to be the bottom end. I will try tightening up the bolts on the cylinder head tomorrow as i remember not doing them up overly tight.
well anouther problem was the sttuds were bottoming out on the head nuts , i sued a washer and that helped alot. the reason this leak occoures is gas leaking from the head preasurises the cooling sytem and the preasure escapes via a valve in the frame somewhere.
well there should be a cirtain amoun of preasure but not too much. what you need to do it warmup the bike , stop and CARFULLY take off the radiator cap, srart the bike and rev it up a bit and there are alto of bubbles u have got a head leak also if the water sloshes straight out that u have the same problem.
All water cooling systems work under pressure as water boils gernerally well below 100 degrees C due to impurities. Have the water under pressure increases the boiling point. Never take the rapiator cap off a warm rad! theres a chance that the water will flash boil and you'll be burnt with superheated steam. As well as the cap turning in to a high velocity projectile
the problem is the head gasket on my way to work the faster i went the more water came out of my rad cap took exhaust of and ther e was water leaking threw the power valve skimmed my head today new gasket sorted
when i skimed the head i also skimmed the barrel but yours shuld be just fine. also with the head nut i used a wsher on each because the nuts had been bottoming out on the stud.