does anyone know what a safe compression reading should be on a 1989 blaster as for as i know its a stock engine as far as bore and power adders but i want to make sure i can rip it with out it blowing up in the first ten minutes

 

not really sure but i would think around 9:1

 

thanks for the input but im not looking for compression ratio im looking for compression psi this is a well used motor and i dont want to hurt it

 

Here is a link with a bunch of useful info for your motor. I think your looking around 160 PSI

1989 Blaster Engine Rebuild - Two-Stroke Software Review - Part 1

 

I have always used 100 psi as a referance point. If its at that point you know a rebuild isnt far off.