Bringing an engine back to life


#1

I recently helped my daughter bring a riding lawn mower engine back to life, after sitting unattened for three years. Nothing had been done to protect it. I drained the old oil (sludge), put in new air filter, spark plug, oil, fuel filter, battery, fuel, air in the tires- you get the idea. When I turned it over it made a horible sound for the first couple of cycles but then after 5 minutes settled down and after 1/2 an hour was smooth as could be (Briggs and Stratton quality). However, my question, is there a correct method to bring back and engine, mower, car, etc., short of a rebuild, back to life? Did I miss something? Should I have put oil somehow in the valves, cylinder…? If the answer is in another area of the blog, thank you in advance for pointing me in the right direction.


#2

You did fine. The bad running initially was likely due to stale gas in the carburator. Some carbs can be drained easily, others can’t. Short of draining and refilling the carb with fresh gas all you can do is drain the old gas from the gas tank and fill with fresh gas.

I’d have shot a bit of oil in the cylinder and cranked the motor over without the spark plug installed. This would spread the oil around before actually starting the motor. Is there a big deal benefit to doing this? Not likely but it can’t do any harm either.

Your motor is up and running and that’s the best you can get. I’d change the oil again soon. That sludgy oil didn’t drain completely since it was drained cold. The fresh oil will free up some of the goop in the motor and that will come out when you drain the oil. A refill with fresh oil then will last a while. Seasonal changes are good for the motor if you want it to last.