is 52 BGM carnk needs engine porting for typh172?

i realised that 54 BGM crank requiers porting, those 52 BGM crand needs too?

 

no, 52mm is standard stroke for 125 engines.

54 is increased stroke and so needs work, same with 55.

 

i thought the 54 needed no casing mods. just the 55 does.

 

is there a lot of diffrence between the performence that 52gives to 54?
i know it's risk that i"m running 172 bore with standart crank.
that's why i asking before buing crank.
those the 52 BGM will make better performance between the standart except that it will calm me that it runing safe?

 

better to be safe than sorry!

and yeh i didnt mean case moding

port alterations and a thicker base gasket/spacer.

 

had this same conversation last week with minor,
to cut it short the barrel/ports are being used differently due to the longer stroke.
(i.e the duration of which the ports are open + the height/width you can port the barrel to)
so unless YOU have the knowledge to make the most of the longer stroke power wise, your best bet is to buy the 52mm crank