yx 150cc

[Ryzzy]

ok i know there is other threads on other sites about these motors, but was just wondering if anyone from here has much experience...
for those who dont know they are the same as the gpx150cc and the same as the 150cc engines that come in the new atomik 150's.
they claim to put out 16 Hp but from all i have read they only put out 11-12 hp stock, from riding one from the joint i work at its easy to see they shit all over the power of a 140. so how much does a 140 actually put out?

i know they have a commmon problem of blowing the oil coolers, has anyone else had any major issues?
Has anyone else done any major work? im not talking homo shit like stupid race cdi's or uni filters...full on head and internal work...porting, stroking,larger valves/springs, cams etc.

[Cactus Jack]

Here ya' go mate ... :

The Gpx 150cc Yx Build Thread!! - Planet Minis Forum = Broken cranks ........

[Mack]

my best guess would be if you dyno'd both 140 and 150 engines in same bike with same decent exhaust and carby you'd see 1 horse maybe more in the yx but similar torque no. for both....

[Cactus Jack]

Yes , the YX150 is only 10 cc (7.14 %) bigger than the Lifan 140 so you could safely expect that it would have around 7.14 % more power at the same rpm .....

[the man]

So the main advantage of the 150 would be the added torque you would get with the extra 7.14% of power. In the end is it worth it getting the motor, or is it better to wait for the lifan 150 to come out?

[edzy]

the lifan 150 is already out
just not here as yet
i can get them, for 550

[Cactus Jack]

Originally Posted by the man

So the main advantage of the 150 would be the added torque you would get with the extra 7.14% of power. In the end is it worth it getting the motor, or is it better to wait for the lifan 150 to come out?

The YX150 has the potential to be stroked to a far bigger capacity than the Lifan can due to its much larger bore and wider cylinder stud spacing ...... it also has stronger case mounts and probably kick starter mech ... but people have experienced the cranks breaking in modded engines that are revved higher than stock ........

And Rizzy ..... you'd HAVE to compare a Lifan 140 fitted with the same sized carb , pipe , plus an IRK and lightened oil slinger (the same as what the YX150 has) to get a true comparison as to what the extra cc's does .....

Theoretically a shorter stroke motor should be more pleasing to ride all day since it has less engine braking and a smoother , broader power curve .....