Reply To: Another TD 20 idling question

[LLOYD LAUTNER]

New rings alone will not solve a compression problem if the cylinders are also worn badly.  TD’s rarely have compression as bad as the numbers you listed because they ran on 16:1 fuel mix and the worn out original primer seals put the motors out of service long before the rings and cylinders wore out. It’s possible that someone ran the motor without sufficient oil and wore it out.  If you properly installed the new rings and LIGHTLY honed the cylinders, it is also possible that the compression will improve when the new rings get seated. But for sure until your compression is better it is not going to idle “good” or at all.