Just split cases on a 125cc txt to change mains. While cleaning crank i have found 4 cork plugs in crank holes which where in a bit of a state! Whats the idea behind these and will there be any ill efect without them?

Edited September 28, 201411 yr by betarick

i think its for aerodynamics to prevent any unwanted turbulence or drag so to speak

They are to reduce the volume of the crankcase so it pumps fresh mixture into the cylinder more effectively

So do i need new cork plugs? seen plenty of other cranks without them!

if they are damaged then yes and they are core plugs , vehicle engine re conditioners tend to stock them

They may well be made of cork. And purpose is as Dadof2 stated. Ir they are deteriorated you will either need to find fresh cork to press in or remove them. I kinda doubt there would be a lot of difference in performance. Balance is not greatly effected with the light cork, and I believe many sizes can be had from hardware vendors right along with the rubber bung plugs.