DT 125r oil burning

[2 Wheels]

This bike is burning gearbox oil and throwing out alot of white smoke, I take it my crank oil seals are leaking ?

Its not been long since I gave it a rebore cause i had some piston slap, how stupid of me not to have noticed oil burning

b4 i put it back to-geather, I hardly ever use this bike anymore only for messin round on, Should I restrip it again to fix

this problem r just keep toping up oil and put up with smoke ?? One more thing What else should i be checking in and arround

the crankshaft if I open up engine this time ???

[Airhead]

This bike is burning gearbox oil and throwing out alot of white smoke, I take it my crank oil seals are leaking ?

Its not been long since I gave it a rebore cause i had some piston slap, how stupid of me not to have noticed oil burning

b4 i put it back to-geather, I hardly ever use this bike anymore only for messin round on, Should I restrip it again to fix

this problem r just keep toping up oil and put up with smoke ?? One more thing What else should i be checking in and arround

the crankshaft if I open up engine this time ???

sounds like the clutch side seal has gone, although both sides would be replaced at the same time. Sometimes you can smell fuel in the gearbox oil too. is this bike used on the road or just a field bike? if its a field bike it would have to be bad to warrant a engine strip, but a road bike will have to be right or you will attract unwanted attention and will no doubt have trouble at MOT time (possibly?)

Its a big job if you have to strip and part the cases so it might be worth doing the bearings too.

[2 Wheels]

I do use the bike on the road but not v much, It only has 4230 miles on it - or so the clock says, should these problems b happening to it if these are the original miles or did the previous one owner drive the guts out of it, What u think

[Airhead]

I do use the bike on the road but not v much, It only has 4230 miles on it - or so the clock says, should these problems b happening to it if these are the original miles or did the previous one owner drive the guts out of it, What u think

I think if its used on the road youre gonna have to fix it, what year is it? if its an old bike the seals hay have become hard and worn. is it watercooled and are you sure that this white smoke is not just steam in the cold air that we now have because that's also white too! until the bike has warmed up to temp...all things to bear in mind

[2 Wheels]

I think if its used on the road youre gonna have to fix it, what year is it? if its an old bike the seals hay have become hard and worn. is it watercooled and are you sure that this white smoke is not just steam in the cold air that we now have because that's also white too! until the bike has warmed up to temp...all things to bear in mind

Its 02 bike and is watercooled, dont think its steam in cold pipe cause took oil level check then yesterday drove for half hour, when i got back and the bike was kinka cold the oil level had droped a bit, smoke is still white when bike is warmed up, sounds like your right about the seals hardening, also when i take out plug there is oil arround the threads of it, how is the oil making its way all the way up to here?

[Airhead]

Its 02 bike and is watercooled, dont think its steam in cold pipe cause took oil level check then yesterday drove for half hour, when i got back and the bike was kinka cold the oil level had droped a bit, smoke is still white when bike is warmed up, sounds like your right about the seals hardening, also when i take out plug there is oil arround the threads of it, how is the oil making its way all the way up to here?

Hmmm i would be somewhat pissed off if my 02 bike with only low mileage was this bad!!!

However you did state the level of oil drops so it does look like youre burning the stuff, To test the RH seal (clutch side) on my bike i could put the gearbox breather tube into a jar of water and run / rev the engine whilst watching for bubbles, this is a dead giveaway wor a sha**ged seal, does yours have a breather tube that you too could try this?

[Cynic]

Hmmm i would be somewhat pissed off if my 02 bike with only low mileage was this bad!!!

However you did state the level of oil drops so it does look like youre burning the stuff, To test the RH seal (clutch side) on my bike i could put the gearbox breather tube into a jar of water and run / rev the engine whilst watching for bubbles, this is a dead giveaway wor a sha**ged seal, does yours have a breather tube that you too could try this?

You dont sound convinced OG and TBH neither am I, lots of white smoke smacks more of water, it has been recently rebuilt too so a duff gasket is by no means out of the question.

The oil level would be dissapearing vquick if its smoking that bad and it would be running like a sack of spanners to boot.

EDIT Also gearbox/4stroke engine oil stinks something wicked when its burnt.

[2 Wheels]

You dont sound convinced OG and TBH neither am I, lots of white smoke smacks more of water, it has been recently rebuilt too so a duff gasket is by no means out of the question.

The oil level would be dissapearing vquick if its smoking that bad and it would be running like a sack of spanners to boot.

EDIT Also gearbox/4stroke engine oil stinks something wicked when its burnt.

To Oldgitonabike -- I have gearbox breather tube so I will try the jar of water thing on saturday, cheers mate

To Cynic -- I used propper yamaha gaskets on rebuid and the water level never drops r needs toping up, but maby a gasket

is failing some how. The oil level is dissapearing vquickly but I dont notice a wicked smell ??

Here's the thing -- the bike looks great and engine is realy clean (no external leakes).Has low miles and is not derestricted. (ill start at the start) Bought bike, had piston slap so done topend overhall,flushed tank and cleaned carborator, checked all settings and made v slight changes, new plug correct heat range and fired her up.Drove easy for 500 miles to brake in.Then stopped using it for the winter appart from starting for a while every now and then.The last month started using again and noiced oil dropping in gearbox and all the smoke. Now Im at this stage -- Bike runs good and has good power, plug is nice light tan colour indacating engine is running as should b. This is what I have noticed -- engine oil dropping, lot of smoke all the time, tail pipe is wet/oily not light sooty as should b.

She sounds and runs good and has good power. Me confused --- (sorry for long post)

[Airhead]

Thanks for the clarification, do the tube test now, unfortunately it looks like an engine out and full strip and seals replaced at this stage.

[2 Wheels]

Thanks for the clarification, do the tube test now, unfortunately it looks like an engine out and full strip and seals replaced at this stage.

AAAAAAAAAAAAAAAAAAAAA Will do the test and take one more good look at everything this weekend.Insurance is up on this bike in 2weeks so I think ill let it slide this year and back into the garrage with 125cc. I luv these bikes as I had one when I was young so to think my little engine is hurting inside means ill have to fix it, have no intension of selling this little girl and want it running sweet. But that doesnt mean im not AAAAAAAAAAAAAAAAAAA about all the extra work ive given myself. A well ne 2 worry. Thanks for all the help, Will let you know about water-jar test !

[Airhead]

Will let you know about water-jar test !

Forgot to say, it may suck the water up or it may blow bubbles ( it should do neither) so draw a line and whip the tube out if the level falls, you dont want water in your gearbox, on this point use a narrow vessel rather than a jar...a test tube for example...if the level falls you will see it much quicker

[Cynic]

To Oldgitonabike -- I have gearbox breather tube so I will try the jar of water thing on saturday, cheers mate

To Cynic -- I used propper yamaha gaskets on rebuid and the water level never drops r needs toping up, but maby a gasket

is failing some how. The oil level is dissapearing vquickly but I dont notice a wicked smell ??

Here's the thing -- the bike looks great and engine is realy clean (no external leakes).Has low miles and is not derestricted. (ill start at the start) Bought bike, had piston slap so done topend overhall,flushed tank and cleaned carborator, checked all settings and made v slight changes, new plug correct heat range and fired her up.Drove easy for 500 miles to brake in.Then stopped using it for the winter appart from starting for a while every now and then.The last month started using again and noiced oil dropping in gearbox and all the smoke. Now Im at this stage -- Bike runs good and has good power, plug is nice light tan colour indacating engine is running as should b. This is what I have noticed -- engine oil dropping, lot of smoke all the time, tail pipe is wet/oily not light sooty as should b.

She sounds and runs good and has good power. Me confused --- (sorry for long post)

Sorry to be a bugbear here but, it shouldn't be running great, it should be a bast4rd to start and the plug should be as oily as the tailpipe, worse even as engine oil (i don't mean 2stroke) isn't designed to burn. Also it does smell foul believe me, really acrid taste at the back of the throat taste.

Its the plug thats making me wonder if you have 500 miles of sludge slowly burning off the pipe, my TDR did it recently and was like a red arrow for a day or two.

How much oil has it actually been through, the way you are describing it it will clear out the gearbox in short order, its only about 70cc between max and min that would be gone in a couple of miles, they do use a little and those little windows are a pain to get good levels from, even the dipstic for mine (and no i don't mean me) isn't perfect. (well maybe its me)

I'm happy to be proved wrong but it isn't shouting crank seals at me.

[Airhead]

I'm happy to be proved wrong but it isn't shouting crank seals at me.

The OG crankcase compression test would be good I know, some things dont seem to add up...like the age of the bike, and the mileage, piston slap at < 5000 miles

[2 Wheels]

The OG crankcase test, Results = Started bike,tube into water. It blows out bubbles at a rate of 1 bubble every 3 seconds at idle speed and this doesnt change as I increase revs. How bad is this? have more findings to tell you on the whole topic.

EDIT:

Was thinking fri nite, 02 bike - 4300 miles couldnt have his many problems!

Searched the house for details from buying bike as knew I had them some where. Got address of the guy I bought it from, and although I did not want to do this- I went to see him. He said (he is old enough fella) he bought bike new and only ever used it to go fishing. He fished only 3.5 miles from his house and to get there went down a little lane and through fields along river.He still does this but now he does it on a quad.Nice fella he was so I believed him and headed back home.

Got home and did the OG compression test!What do results mean I wonder. Then I lifted bike off the ground to waste height, started and put it in 2nd gear to simmulate driving on road.While looking round it I could see no probs to hand, then I walked pased the back of it and it spat oil on me. Looked again and noticed this.

"No external leeks my ass" A little drop of oil was comming from drive sproket and dripping down onto chain. I put the bike through the gears like mad and as engine temp rose the drip went mad onto chain, arround and flew off the back.No oil at-all on engine casing.

So could this b right --- This is where my oil is going so fast.The old fella that had it before never drove hard enough to burn oil outa pipe so I have 4300 miles of sludge in pipe. Plug is right colour cause engine running ok. Piston slap because maby he was overreving all the time.

Could I be this lucky??? Have exhaust off for cleaning tomorrow. What you guys think ?????????

[Airhead]

The OG crankcase test, Results = Started bike,tube into water. It blows out bubbles at a rate of 1 bubble every 3 seconds at idle speed and this doesnt change as I increase revs. How bad is this? have more findings to tell you on the whole topic.

How bad? any leak is bad you need 100% sealing, besides that test is done with the bike stationary under no load conditions, its likely to be a worse result with the throttle open and the engine working the problem can also be masked as the engine sucks in oil under negative pressure pulses in other words if the engine sucks in a bubbles worth of oil then thats a bubble you wont see.

[Cynic]

The OG crankcase test, Results = Started bike,tube into water. It blows out bubbles at a rate of 1 bubble every 3 seconds at idle speed and this doesnt change as I increase revs. How bad is this? have more findings to tell you on the whole topic.

EDIT:

Was thinking fri nite, 02 bike - 4300 miles couldnt have his many problems!

Searched the house for details from buying bike as knew I had them some where. Got address of the guy I bought it from, and although I did not want to do this- I went to see him. He said (he is old enough fella) he bought bike new and only ever used it to go fishing. He fished only 3.5 miles from his house and to get there went down a little lane and through fields along river.He still does this but now he does it on a quad.Nice fella he was so I believed him and headed back home.

Got home and did the OG compression test!What do results mean I wonder. Then I lifted bike off the ground to waste height, started and put it in 2nd gear to simmulate driving on road.While looking round it I could see no probs to hand, then I walked pased the back of it and it spat oil on me. Looked again and noticed this.

"No external leeks my ass" A little drop of oil was comming from drive sproket and dripping down onto chain. I put the bike through the gears like mad and as engine temp rose the drip went mad onto chain, arround and flew off the back.No oil at-all on engine casing.

So could this b right --- This is where my oil is going so fast.The old fella that had it before never drove hard enough to burn oil outa pipe so I have 4300 miles of sludge in pipe. Plug is right colour cause engine running ok. Piston slap because maby he was overreving all the time.

Could I be this lucky??? Have exhaust off for cleaning tomorrow. What you guys think ?????????

Now this sounds more like it, one little bubble will be the expansion as the motor warms up, exactly the reason the breather is there. The oil on the sprocket will be from a duff seal, crap from the dirty lanes it has spent its life traveling down with a big bloke + kit at no miles an hour.

Also the piston, running slow 'riding the torque' is actually not all that good for a 2 stroke either, they are actually beast suited to generators and such where they can be left running at the ideal rpm where the piston 'floats' in the centre of the bore. Extreems of rpm no matter high or low will cause excessive wear, it has probably spent its entire life on choke to boot which will add to the piston wear.

It sounds to me like you have it nailed, it certanly ticks all the boxes for me. Unfortunately there is no easy way of cleaning the pipes. All the options are either flammable/toxic/corrosive/cost in various combinations.

It may all be relatively soft and oily, parrafin (or lamp oil, thats cheaper but the same stuff) left for a day or 2 or diesel.

Or if you are carefull and use gloves ,goggles etc get yourself some caustic soda crystals, proper stuff not that cilit bang crap make it up good and strong and leave that in there for a day or so.

Or! Fill the tank pick a looooong road and thrash the living daylights out of it till the smoke stops .

[root]

Well it sounds to me like your losing your oil directly from gearbox through the sprocket seal , By all means clean exhaust as previously described (caustic soda) this may sort smoke out but not oil loss , so I think you nead a new sprocket seal to stop this !

[Airhead]

Glad you got it sorted, I overlooked the expansion of the oil as the motor warms up, thanks for pointing this out Cynic...so its not a major problem after all and no need to split the motor...result, always did seem far fetched though for such a young bike surprised it even needed a rebore, maybe a new set of rings would have done eh?

[2 Wheels]

Oldgitonabike,you were signed out lastnite by the time I typed the rest of my post, im slow typer (one finger typer). Is your OG test only to test the RH and LH mainbearing seals or does it test all seals in gearbox and I take it it's only for twostroke engines ??

I am so happy today Will have it sorted in no time. Order new seal and exhaust gasket on monday and get it done. Will do the caustic soda cleaning on pipes as heard before its good plus because do I realy have enough brake-in miles done to give it loads down a good looooooong road. But I will give it loads + loads down road eventually.

Yourself and Cynic are two good engine heads and I thank you for all your time + help

Maby new rings would have done but to be sure i rebored as keeping bike and wanted it going good. Now it appears I have good engine + bike with low miles, happy days

[Airhead]

Oldgitonabike,you were signed out lastnite by the time I typed the rest of my post, im slow typer (one finger typer). Is your OG test only to test the RH and LH mainbearing seals or does it test all seals in gearbox and I take it it's only for twostroke engines ??

I am so happy today Will have it sorted in no time. Order new seal and exhaust gasket on monday and get it done. Will do the caustic soda cleaning on pipes as heard before its good plus because do I realy have enough brake-in miles done to give it loads down a good looooooong road. But I will give it loads + loads down road eventually.

Yourself and Cynic are two good engine heads and I thank you for all your time + help

Maby new rings would have done but to be sure i rebored as keeping bike and wanted it going good. Now it appears I have good engine + bike with low miles, happy days

Youre gonna need some sort of a rubber bung to stop off the end of your pipe....wine cork? i dunno ! Dont cut any corners with the caustic soda, wear goggles or better still a face mask and gloves and take care!!! its nasty stuff.

if I had room in my garage there would be one of those little beaut's in there too, now how about a picture?