DT125R ARCHIVE

coastie123 · DTR Senior Member

Possible head gasket, crank seal or water pump!!!

NORFE · DTR Trusted Engine Builder

id say water pump seal or clutch casing gasket as that's the only place water comes close to the tranny oil mate
if the seals gone have a look for a small hole on the underside of the waterpump case if its wet its the seal leaking
if the clutch case gasket it re-used it can leak as theres a ring of silicone around the hole on the gasket and peels off when u take the cover off most of the time

coastie123 · DTR Senior Member

Cheers fella

It can't be the crank seal again!!!

Can you pm me the sizes of the crank seal and the place you got them from just incase??

What's the best option for cleaning out the gearbox??

NORFE · DTR Trusted Engine Builder

wont be crank seal if it was the crank seal the head gasket must be leeaking as thats only place watet can get in to the engine then in to the gear box

diesel or petrol thats all i use drain it off then fill it with petrol/diesel kick it over few times give it all a good rinse drain off then oil, may need to do it a few times b4 its all gone

id put £ on water pump seal did u not replace it when u built the engine

coastie123 · DTR Senior Member

Yep all replaced, I fact every seal/gasket was replaced!! that's what I can't workout!!

NEV · Guru

Daft question Coastie, but did ya put the water pump seal in the right way round? it's easily done mate.

NEV · Guru

If you need to buy some coolant, try that Silkoline Procool (ready mixed), you can get it from Halfrauds, its blue btw, lol

-- Edited by NEV on Thursday 2nd of August 2012 06:08:40 PM

coastie123 · DTR Senior Member

Yep definately the right way round...

I'm gonna change the seals to be on the safe side and also use red 2T and green coolant.. That way I should know which is leaking!!!!

Just need to flush out the old green 2T before I put the red in!!

coastie123 · DTR Senior Member

At this rate I would of bought the entire colours of the rainbow!!!!

MDK · DTR Legend

would have thought if coolant was mixing with oil it would have gone milky ? and not juist green ?

coastie123 · DTR Senior Member

That's what I thought, the gearbox oil is definately a bronzey oil colour but the sight glass is showing green!!!

I'll have a look at weekend and let ya know!!

MDK · DTR Legend

sight class can be hard to tell sometimes it can also make it look realy black untill you drain or open the cap .... CHECK IT AFTER BEEN STOOD OVER NIGHT open the cap and tilt bike over so you can see if any silky whiteness on top of oil or if it looks murky .... maybe like you say above it could be a strong die in the 2 t oil thats turned it

coastie123 · DTR Senior Member

right guys, just spent half hour in the garage looking at this bloody green fluid.. Looked like coolant...

drained it all out including the coolant (into seperate pots...)

stuck my hand in the gearbox oil and it all seemed to feel like oil here have a look..

My conclusion - It feels and smells like 2T

heres the set i bought http://yambits.co.uk/dt125r-engine-oil-seal-kit-p-2400.html

I also changed the crank seal as it was knackered so it's definately not that...

could it be the oil seal behind the pump or possibly the oil pump?? as I said before it definately smells the same as my 2T

NORFE · DTR Trusted Engine Builder

nice toxic waste oil lol

stick an oring behind the pump, i dont no what years its on but some have a small oring on the end of the drive shaft that goes in the pump. it states in haynes (dont forget the seal) some where as i can remember reading it

coastie123 · DTR Senior Member

It's a 1999

On ajsuttons it's a 1999 DE031

Will have a look