In the past I've kind of poo-pooed the "old gas" debate because gas sits in my mower and 38 all winter with no issues. That is until about a month ago. I've not driven the 38 nearly as much since getting the 53. Last winter's gas hasn't been renewed by new, fresh gas over the summer. I finally decided to get the 38 out of the garage a few weeks ago and all was good. I drove for an hour or so, still on last winter's gas, then put it away. About a week ago I decided to get it out again and was startled to have the starter drag so bad I thought the battery had died. It finally started and I discovered that the battery was good but stuck valve(s) were resisting the turning of the engine. CLATTER, CLATTER, CLATTER! What the heck??? It was running, barely, as I got out of the car to open the hood to see where the noise was coming from specifically. In the time it took to get my old, well fed body out of the car and get the hood open it started to quiet down and run more smoothly. It was at that time I decided it was sticking valves at fault and probably the old gas building up varnish on the stems that was causing it. I was fortunate enough that they didn't stick bad enough to bend pushrods (been there before). I siphoned out the remaining gas and disposed of it at the local hazardous disposal site. I poured in 5 gallons of fresh gas along with a can of Chemtool and started it back up (this was the next day). Sticking valve(s) again but not quite as bad. After about 30 seconds it smoothed out and ran well. I took it out for a drive to give the Chemtool solvent a chance to work and shut it off to sit over night. Next day no improvement. Two more cans of Chemtool, another 5 gallons of fresh gas from the station and a couple of hours of driving and I put it away again but with some trepidation. If it didn't improve I was going to have to pay someone to pull the head and clean the valve stems since I can no longer lift the head. I ventured out this afternoon and, with fingers crossed, fired it up with no sticking. YAY! Lesson learned, drive the darn thing!!! Gas CAN go bad after a few months, to the point of gumming up valves.
