Re: lower compession cause in early V4?
Oil would only change the reading temporarily .If you were to repeat the compression test ,after several cranks if there was say a bad ring clearance problem , it would show itself.Moreover ,if there was a cylinder whose compression was significantly low ,it would have not attained a 125 reading with oil.<br /><br />As for the lower compression reading on one particular bank,I would guess that it may be a carbureted issue which either deposited more carbon over time to the ring grooves or even a slight lean condition that may have caused some minor scoring of the bore.Can't do much to address the latter of the two ,but you could try a decarb in an attempt to dislodge any carbon that may be present in the ring grooves or cylinders of the lower reading bank.As already noted , you don't really have a problem with the compression readings,as is.However,If this engine has sat out of use for an extended period ,a rebuilding of the carburetors would be in order.This will prevent leaning out of any cylinders and raining on your good compressions parade.Good luck.
