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I am restoring an Evo 2, 2000 model. I have been trying to find information regarding setting up the squish. On Issuu.com I have found a 1999 Evo manual and a 525 manual.

Both state the compression ratio is 7.1:1.

The Evo 2 and 525 manuals both state to set the squish by fully inserting the piston into the assemble barrel and head and measure the distance from the spark plug seat on the head to the piston top as a datum. When the piston and barrel are fully assembled the distance should now be the datum + 1.55-1.6mm. So this is all pretty straight forward so far.

The only thing is I have read people saying to set the squish to 1.2mm for road use. Is this just to get a higher compression ration to give greater power or is there some other reason for this?

I am more bothered about (relative being a 2 stroke) longevity than peak power.

I would be interested to hear from other Mito owners.
 

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The motor will run better with the correct squish , 0.8 mm is this number , but it also requires the correct compression ratio , that depends on some other things , exhaust port height , combustion chamber volume mostly
You can find out how to calculate these via the www
Ideal compression ratio seems to be 14.9:1 , but I can’t remember the chamber volume ( been a while since I built one )
But it’s around 12cc iirc
The factory settings of 1.6 + mm for squish are to try and keep it in one piece
 
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