That's precisely why you make a new motor slug hard within the 1st 20 minutes (without revving it too high) to get the rings to lap and bed into a perfect seal on the bore .. and to achieve THAT .. you WANT to leave the crap oil they come supplied with in them ...
Loading the engine hard at low to mid revs builds high cylinder pressure that gets behind the rings and forces them out hard on the bore and causes them to wear quickly to suit the bore wall without creating too much heat ... Crap oil allows that rapid controlled wear to take place ... Even the metal shavings that people talk about help to lap the rings into the bore ... the piston especially will shed a fair amount of metal which is necessary to get it to wear into the right shape and will appear as a grey sludge in the oil ... fine alloy shavings cannot hurt steel or iron ... Oil pump impellers are made of super hardened steel ... far harder than anything that'll wear off the bore or gear teeth ...
When you get a new motor ... don't mess around idling it or tuning it .. get the frigger into gear and pulling hard as soon as you start it ... get it into a taller gear and throttle it hard , make it lug , let it rev to just over half revs then back off leaving it in gear to engine brake without even pulling the clutch in each time ... then do it again several times ... stop to let it cool .. then do the same thing again several times .. gradually increasing the rev limit each time up to 5/8 th revs ... Then as you feel it freeing up keep doing it until you can rev to 3/4 throttle .. Gradually increase to brief peak revs in the following days Poorly bedded in motors have poor bottom end torque and the oil will smell like petrol ... then the oil gets fuel contamination right throughout its greatly shortened poor performing life ... When you come up against a properly run in bike with the same engine , you'll get beaten every time ... then you'll be talking about the lucky guy with the "freak" Lifan 140 who creamed you ... and maybe even suspect that his engine was "worked" ....
Some people get too paranoid with their oil changes and it's the short lifed late model MX 4 stroke engines that have made people think like that ... Boy the manufacturers have got people conned ...
They've deliberately built these short lifed engines to soak money out of peoples' bank accounts ... Ask them to explain why the exact same cylinder can be revved harder for hours on end in a road bike without a scrap on maintenance or daily oil changes ...
It sounds to me like someone has "pansied" the "new" 140 engine and this is the end result ...
The fact that it has an IRK fitted says a lot ... I'll bet it's done 2/3rd's of its short life revving in neutral or with the clutch in and the other 1/3 revving freely in the lower gears ...
