how to check squish on a 2 stroke engine

[baorevo]

A little vid showing how to check the squish on our 1/5 engines

 

[saviown]

also works on glow engines, dave marles from Prestwich models told me this trick years ago when I was doing boats 

[Jacksprogis]

Video isn't working for me  

Jack

[Anthoop]

Maybe worth mentioning to position the solder above the gudgeon pin for accuracy (doing both sides and taking the average and measuring with micrometer for best accuracy)....if you put the solder in other positions then the reading will not be so accurate due to the piston rocking.

[norney hurtmore]

more accurate way is with the depth guage on a vernier

before assembling engine, slide piston as far as it will go into head (without piston ring fitted)

measure with vernier

assemble engine

wind piston to TDC and remeasure

subtract original measurement

= squish

[wolfie1]

You know in all my years i have never done this before when rebuilding an engine, so whats it for?

[Oh How Original]

It's for making sure the squish is correct, if I understand it correctly, too much (too low of a number) will give you more bottom end power, but pretty much ruin the engine, and not enough (too high of a number) will lose compression and power?

If I remember correctly about 0.55-0.65mm is best.

I could be wrong but pretty sure.

[wolfie1]

Thanks, so now i do :-)

[Oh How Original]

9/10 it'll be fine as long as you change the head to the correct one, but sometimes a 1mm copper gasket is needed with a stuffed crank