HELP! 125cc DIRT BIKE PROBLEM, SERIOUS

[LOL]

hey there guys, i recently bought a 125cc dirt bike, ran half a tank through it, it ran fine, loved it, however wasn't so good the next time..
the first time i put petrol into it and tried to start with electric start it made a jamming noise, like a gear box crunching sound, but then it soon started and ran fine, very good power, thought it nothing

seccond time, tried to start, held electric start, it wouldn't start, occasionally making that gear box crunching sound (mind you the gear box is fine, changes gear really easily), even with kick start it wouldn't start.

left it there for the night, next day i changed the oil, tried to start it, has compresion, but same thing happens, gear box crunching sound again, so i took off the spark plug, fouled as, REAL BLACK build up, i sanded it down abit, poured fuel over it lit it on fire, put out the fire and pluged it back in, tried to start the bike, took a while to start, but it did, it was running but cut out in 7 secconds? it didnt sound normal aswell, seemed to be missfiring/backfiring and running rough, and then where the header conects to the muffler there was a oil spit.

 

[mjc85]

Well oil coming out the exhaust isn't a good sign, you've either got to much oil in the sump and it is somehow getting into the cylinder.

Are you sure you have undid the zip tie from the crank case breather ? because if not you may have blow a crankcase gasket or something

 

[LOL]

Are you sure you have undid the zip tie from the crank case breather ? because if not you may have blow a crankcase gasket or something

sorry i dont know what that means, i haven't pulled any zip ties appart, and i dont know where the crank case breather is...any help please? thanks...i appreciate it

 

[walker]

help

Are you sure you have undid the zip tie from the crank case breather ? because if not you may have blow a crankcase gasket or something

sorry i dont know what that means, i haven't pulled any zip ties appart, and i dont know where the crank case breather is...any help please? thanks...i appreciate it

if you look to the back of the motor you should see a black hose. it will run down behind to underneath. it will be clamped or zip tied. very hard to see but its there

 

[LOL]

hmmmm ok, theres a hose coming from the back of the engine, its held onto the engine by a yellow clamp....then it goes down to the swing arm area. theres nothing restricting it? no zip tie no nothing, however i dont remember taking it off, anyone lemme know what to do? cheers

 

[RabidDog12345]

the breather should be just behind the ignition switch where the key is... its usually a black hose and is doubled over and ziptied...

 

[Franky]

K, i've have a few probs with theses bikes myself, First of, the bang sound you are hearing is nothing, You are probably seeing smoke coming out of the air filter aswell, Its just a little issue theses bikes have which does absolutely no damage, Now to the starting issue, Sounds like your pisten ring is gone, When the piston ring is gone the muffler will be full of oil and it will burn oil, Or, you have put to much oil in the bike and its getting into the barrel, Now if you have left the clip on so the bike cant breath that would just be causing the bike to leak oil, because a oil seal comes off in the engine which then lets the bike leak oil.. not a big job to fix but a pain if you dont know what your doing..

 

[pascal125]

oil out the exhaust? whoa, i never had that be4. ummm, the bike would be stroke of course, when you put the oil in, how much did u put in? usually there is a stick and at the end there is a ring in the way and for about 3cm's below there are like crosses, only fill it upto the top of the crosses, usually about 1litre, im guessin u already knew but if u did fill it right to the top of the tank like you would with petrol then that would be, but chances are it's something like what franky said with the piston rings

 

[kyunt]

yeah it's fouled because your running the fuel too rich, move the 'e-clip' up two notches. and it should be all good (at least to start anyway, i dunno about the oil part)

 

[akim21]

hope u didnt put in 2 stoke oil

LOL