70cc still not going : (

[jackbmx2010]

aye guys, my 70cc atomik still wont start. has brand new head and valves ect.. brand new carby, new lead. timing is set right from advice on previous posts and so are valve clearances. has fuel and spark but is a bit low on compression. when i kick it over it sounds like it is gonna start and white smoke comes out the exhaust and the motor gets a little bit warm after 20 or so kicks so i think it is firing but it wont go. i think the problem is something to do with the breather tube coming from the lower engine casings. when i kick it over a mist or smoke comes out but it doesnt smell like petrol. i cant think how smoke gets from the combustion chamber to the casings where the breather pipe goes to except for the rings but im not a mechanic so i dunno for sure. can anyone help with the last piece to the puzzle ??

 

[sean01]

well you've confirmed everything else apart form the rings..

one one would think thats where your problem is... smoke from the engine breather tube is a sign of worn rings..(blow by)

i cant really remember your last thread but im wondering why you changed the head and valves!!

 

[jackbmx2010]

The last threads were just trying to figure out why the engine wasnt holding compression properly and wy petrol was coming out of the carby which the new head fixed both of the problems. i replaced the head cause the spark plug hole was stripped and the only replacement head i could find came with the whole valve assembly. i was pretty sure it would be the rings. i'l pull apart the motor and have a look. thanks for the help

 

[sean01]

ok,
was the replacement head for a 70cc engine?

 

[jackbmx2010]

yep. this is the link. 70cc Engine Complete Head Assy/Lifan/Zongshen/Loncin - eBay, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 06-Aug-10 01:54:36 AEST)