I have heard for years the if you keep a steel spring compressed it will loose tension. This old wives tale must have sprung form bow and arrow day in that if you didn't unstring your wooden bow it would loose tension. Very true for a wooden bow - not so with steel springs. My father had a Cadillac sitting for 6.5 years and with a new battery fired right up and still runs fine. If anything your valve guides and stems could be gummed up with old castor. If it were not for castor's durable film strnght at high temperature there would be not reason for a sane man to use the stuff.

Bill