Z155, 160ho or 175ho which engine?

[Motovert17]

I'm looking for a new engine to put in1

Of my motoverts I'm looking for a pitsterpro engine 155z,160ho,175z which 1 one of these motors will be most reliable and fast?? I only want to keep the engine STOCK!! No upgrades except oko flatslide carby

 

[grnman]

would i be correct in saying that putting a 63mm big bore on a motor would lower the reliability of the bottom end, gearbox and clutch.

lets start a poll.

i vote for 160ho

 

[coolmodee01]

maybe
my 175 has done well over 60 hours on the g/box

 

[Motovert17]

Are the 175 reliable? And do they go any harder than the 155??