Airhead

An old school tap will say on it OFF...RUN (or ON)..RES and have only one tube...fuel to the carb a more modern vacuum tap will say on it RUN (or ON)...RES...PRI and will have two tubes, one is fuel to the carb and the other smaller tube is vacuum to the carb manifold

By the way its a fairly modern bike, so has it got a vacuum operated fuel tap? This means that when you have had the carb apart you MUST switch to the 'PRI' or 'PRIME' position for a while in order to re-fill the carb float bowl...this applies when you have worked on the carb and when you run the tank completely dry.

I edited my post about has it been in a lot of rain, dont think you saw that. can you remove the cover fron over the magneto (left side?) and see if theres any sign of dampness in there and and inside of the case, start the engine and spray with WD40 through the gaps on the flywheel, this wont do any harm at all and worth trying. Also spray the ignition coil, the HT lead and cap and while youre at it...the sidestand switch.

What year is the bike? Have you got a haynes manual or similar? Sounds like electrical (ignition) issue now as you have done most to the carb, but on the subject of carb you cant clean it properly by just soaking it for a while, you actually have to pull it apart including all the jets and clean everything properly with carb cleaner and compressed air (or an aerosol air spray available from computer shops) Also was it a very wet day when it started playing up?

Just open a photobucket account, look in FAQ's and show us yours,

You need to check for bad connections, are you in the habit of checking battery levels and topping up accordingly?, maybe the battery is on its way out, will it operate the horn?, I must admit that indicators on 6v bikes aren't that good

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?

Hi Vincent, theres a pinned topic on DT125 tuning and mods in the 'Workshop' forum.

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?

Welcome fulmar You sold the LC .WHAAAAT

How is your problem similar?

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.

Welcome to the forum winklepie. you need to speak to member 'Gas up - Lets go!'

Remove the bleeder bolt (Plug) from the top of the pump. With the engine shut off open the throttle fully and rotate the white plastic plate in the direction of the arrow on the plate. Continue until air bubbles cease to come out of the bleed hole. Re- install the bleed screw ...job done.

Did he really forget to mark the cup?????

Coming home from work tonight when suddenly progress came to a standstill at Mottram for a while, evantually get moving and 600 yards up the road theres a bike on its side and the rider lying on a driveway (people were attending). Hope he's ok and all you commuters take care especially now the journeys are in darkness.

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

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

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.

I can only assume that 'pop the clutch' means bump starting to us this side well pop the clutch then remove the plugs, are they wet with fuel? A compression test might be appropriate too! or failing this,,,squirt some oil into each cylinder and try again to bump start the bike, this should improve the compression if its low and can sometimes help start a worn engine

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?

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

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.

my kind of girl

so you tried starter fluid...............and?