never checked my squish clearance, can I do it without removing the head?
Yep. Remove the sparkplug and get 2 pieces of electrical soldering wire about 2mm thick.
Cut the 2 pieces about 125mm long and give them a slight bend into a L shape.
Turn motor over slowly until the piston is about 20mm from TDC. You can hold a screw driver or similar down the spark plug hole and get a feel for when it is just before TDC.
Next , feed the 2 pieces of solder into spark plug hole ( don't drop them in ) and push them 1 at a time until the bent end or L is touching the cylinder wall.Have them opposite each other in line with the crank.
Slowly push down on kick starter until you feel the piston contact the solder and then push past.
Remove the solder and measure with a micrometer or vernier.
The measurement is your squish clearence.