I have a 2002 DT 175 got it 2 weeks ago of a guy I gave the carb a good clean it has been going not to bad, mind you it dos have a an oil leak on the bottom clutch side casing its only a drip. checked the oil level this morning it showed full went for a ride to the shop this afternoon on it first ride today about 2km there and back and the oil light come on when I was nearly home checked oil again its GONE ? WHERE ?

are we talking about 2 stroke oil, thats what the red light is for.

or gearbox oil which will be affected from your enfine leak

2 stroke oil is better part of half full I was talking about gearbox oil .. sorry should have made that clear if the light comes on for 2 stroke oil at half full ?... but no I mean the gear box oil where the hell did that go ? I Have a crm 250 I keep in Thailand and I use auto transmission fluid for gearbox oil picked that up off of CRM250.com and for that mater I use it in my CR500 as well works rather well I was planning on using it in this little DT 175 I got it as a work commuter, but I am having a guess but I am thinking my seals have gone in the little bugger the oil drip off the clutch side is not bad enough to lose all of it in a 2 km ride surly ?

Hmm well it's leaking worse than you imagine then !

Yeah the red light is just for 2 stroke oil and Is always on in neutral

yes I have worked that one out but after a ride and parking it on the pavers over night there is only a drop that is unless when riding its being pushed out the leak in the gasket a lot faster I will top it up again in the morning before heading off to work if the bloody thing blows up I'll take the plate off it and will leave it where it died haha not worth mucking around with it.

Crank seals have probably gone, and you're burning it more than leaking it.

But 2 Kilometers " must be smoking like a train, gear oil smells different too,

Depends whats in there. Ive heard and seen allsorts in 'boxes. Two km is quite short a distance. The old dt gearboxes are quite resilient to oil starvation though, they can take alot of abuse.

Does it feel lumpy through the footpegs? If not then you still have some lubrication!

For the sake of a gasket, change it, making sure the surfaces are clean and even, and see how you go.

Also, its hard to tell how.much its smoking when youre looking forward. Hehe.

yes the old girl is blowing a fair bit of smoke gray, this morning I checked the oil before adding some more it was half way back up the stick again toped it up and off to work on the way home stoped at the local bike shop the guy says he can put new crank seals in it with out splitting the motor but is to busy to do it until next week he says he can have it fixed for me for under $200 so that's not so bad.I would do it myself but am somewhat short on the right tools to do the job.

You.shouldnt need much in the way of special tools, maybe a flywheel puller, but these are cheap on ebay, and I.dont know the exchange rate, but the seals should be less than £10.

you wont even need a flywheel puller if you only change the 'wet' right side seal

True. Maybe a clutch holder then.you do need to take that off.

i ordered the right side crank seal $14 and a O ring $5 not sure if its needed but ... and gasket $30 i will still get the guy at the bike shop to put them in at least it will save time him having to wait for the parts. the next little job i am going to do is cut the guts out of the expansion chamber and weld it up again.