I have had an interesting experience with a one cylinder engine on my old lawnmower that I bought in 1992. Three years ago, it began using copious quantities of oil. The blue smoke was so thick I was fogging for mosquitoes as I mowed I switched from 30 weight specified in the manual to full synthetic 10W-30. The switch to synthetic cut the oil consumption by 75% until the end of last season when it began using oil and smoking heavily.
I figured that it was time to replace the mower, but I hadn’t purchased a new mower when the grass was ready to be mowed. I got the mower out of the storage shed, changed the oil, put in a new air filter and sharpened the blade–the same thing I always do at the beginning of the mowing season. However, I had forgotten to buy a new spark plug. I removed the old spark plug, cleaned and regapped it, replaced the spark plug and started the engine. It smoked heavily and had used quite a bit of oil. I was in the farm store buying dog food and just happened to go down the aisle for small engine parts. I couldn’t find the Champion LM19 spark plug specified in the manual, but did find a RLM 19 Champion which is a resistor plug. I replaced the old plug with the resistor plug. The first time I mowed after putting in the new spark plug, the engine smoked less and used less oil. Since then, it hasn’t used any oil and doesn’t smoke at all.
I really don’t think putting in a resistor spark plug cured the oil consumption. My guess is that the engine had a stuck piston ring, but if that was the case, could the piston ring become unstuck?
I would like to think that I have found a cure for oil consumption. If I could figure out what I did, I could get rich selling a cure for oil consumption.
Maybe the synthetic oil helped remove some sludge or carbon and freed the stuck ring?
A spark plug won’t fix oil consumption. If it was missing badly, it might fix gas (black) smoke problems.
I am not sure. I know people who would use Seafom to help with stuck rings. (It’s mostly for stabilizing gas for winter storage.) Perhaps the synthetic oil cut thru a bit of carbon. Another older cure was to squirt Marvel Mystery oil down the plug hole, repeated every time you go by for a few days, then fire it up after maybe 4 days… so maybe worked that way?
Just total guesses.
I had a similar experience with 1972 Plymouth Duster I bought for a work car in the early 1990s for $200.
The cjy I bought it from lived 1/2 mile from work , used it mainly just for work and the oil looked like liquid tar. It smoked like mad.
I changed the oil with Valvoline 10W30 and as soon as I changed it, it was coal black. I changed it again in a week and again in a month. It would occasionally give a big lurch, blow a smoke ring out the tailpipe and run a little better. After 6 lurches that Three on the tree slant 6 stopped smoking and burning oil and ran smooth as new.
The 225 Duster. Loved the engine and would love one that blows smoke rings (on command). lol
I hadn’t thought about that. My old one-lunger BS’s almost never had the oil changed. (It’s been 20 years since I had a 4 stroke that lasted a year.)
What else happened on the day it stopped consuming oil? Maybe it had something to do with that drone the Iranians shot down?
an interesting connection . . . ?! 
I once found straight 50 weight oil and used it. The oil ring was broken and I didn’t want to buy another because of the scored cylinder wall. Darned if I can remember how it worked in 1971.
A plugged breather can make it smoke too. Other than that don’t know. I did have a smoker on my old rider though and put chrome rings in it that was supposed to do the trick. Didn’t work as I had hoped and just put a new engine on it.
I always thought that the purpose of resistor plugs was to reduce electrical “noise”. I don’t see how this would reduce oil consumption.
@bing may have the answer. There must be someway that the crankcase is purged. I don’t think the blowby is vented to the atmosphere as were the small engines of the 1950s. I know that there isn’t a PCV valve, so there must be some way the fumes are sucked into the engine. Perhaps that passage was blocked and then opened up.
Whatever the case, I don’t want to jinx it because I already spent the money budgeted for a new mower on beer.
I solved my lawn mower oil and gas consumption by buying a cordless electric mower . One of the best purchases I have made. They even have cordless riders now for commercial use.
I’m going with unstuck oil control ring by synthetic oil.
Manual mower: saves a trip to the gym to boot!
After a lifetime of being paid to lift things, the idea of paying to exercise is jusy ludicrous to me.
Who would you be paying?
I save money by doing my own work. A riding mower is a lot more expensive than a push-mower. Even a self-propelled mower costs twice as much to maintain as a normal gas mower.
Having respect for one who has spent a lifetime of lifting things for money, I don’t blame you one bit for hiring someone or using a riding mower. I wouldn’t begrudge you for drinking and mowing if your riding mower has a drink holder.
@VOLVO_V70. Several years ago, I bought a used Black and Decker cordless electric mower from a friend. The batteries gave out after one season. I bought new batteries, but the new batteries only lasted two seasons. I bought another set of batteries at the beginning of the season last year. I mowed for less than five minutes and the mower stopped. I took the mower apart and I can hook the motor directly to the batteries and the motor will run. The problem is in the controller board. I am tempted just to bypass the board with a switch.
This mower used sealed lead acid batteries. At $65 for batteries that only last two seasons, I can buy a lot of gasoline. Besides, the mower is heavier to push than the gasoline push mower I have.
I know that the new cordless electric mowers use a lithium ion battery. I may go that route. I have a cordless electric trimmer with the lithium ion battery and it works great.
All those are the reasons I opted for a corded electric mower.
I’m so cheap that I’d rather have to deal with a long extension cord than fork over that kind of dough for replacement batteries.
Yep. I have one of those early electrics in my storage shed. Better batts and a different charger helped… but there it sits w/ a dead batt. Some of the newer ones work very well, but I passed. I assume they have moved to lithium batts. (I considered those as replacements for the old electric, but it’s not cheap.)
Funny you mention weight. I moved to corded electrics for that reason. One of the small ones weighs 20 pounds and had a handle atop. My favorite has all the features of a gas, except it’s not self propelled. It’s lighter, quieter, gets thru tall grass without stalling and seems to do a better job picking up clippings. I found a pattern so the cord isn’t in the way, and no more trips to the gas station every couple mows, and worrying about gas cans dribbling in my car.
I also have one of the old push reel mowers, picked up from a garage sale. The kids loved it… volunteered to mow the lawn a couple times. It was worth the $10.