KX Riders

Maintenance & Technical => KX250 / KX125 => Topic started by: SOHC on December 10, 2015, 08:36:19 AM

Title: 250 cylinderhead squish
Post by: SOHC on December 10, 2015, 08:36:19 AM

I have a 1990 kx250 that i have just rebuilt the engine, i checked the piston to head squish and it has only 0.43mm including the gasket, i had the cylinder bore re plated and they refaced the cylinder deck so that must have decreased the clearance a bit, also the head has been planed at some stage in its life.

What should the clearance be?
are they any good mods to do when I take it to be re mechained?

Title: Re: 250 cylinderhead squish
Post by: LukeG on December 10, 2015, 10:13:39 AM

I was told by to aim for 0.75-1mm squish. You may need another base gasket.

Title: Re: 250 cylinderhead squish
Post by: SOHC on December 10, 2015, 05:51:52 PM

Cool thank you, I am going to try another head as I think mine has had the holey s**t planed out of it.


I can't seem to find the info for a 1990, they say if you get the squish right they go very well