Generally on a twin, the compression is around 125-135. sometimes higher, depending on the model. Triples can be little lower sometimes, they like to rev more. Important thing is that they should be within 10% of each other. If you have comp. near or below 100 psi. you need to tear it down. Note that not all guages are the same, hence the 10% rule.
If yours seem too low, try another guage for comparison.
