an ideal compression reading would be 150psi
but if engine has wear on it then you will not get that high of a reading, according to the engine manual any cylinder should not read anything less than 100psi on the guage. And there should not be a variance of any more than 70% from the high cylinder psi and the lowest cylinder psi reading.
ie: if the highest cylinder reading was 150psi then the lowest allowable reading on any other cylinder can be no less than 105psi.

You can do a compression check if you like but i would also pay attention to the LP Vaporizer, make sure its not freezing up. Also check your LP filter make sure its not stopped up.

Some things to check after it warms up is note the temperature reading on the guage (if it has one), make sure its not running hot. When you start the engine does it sound like its laboring hard when turning over?

Just a couple of things to consider :o)