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I did this to a 4 stroke lawn mower. My bad entirely, there were stickers on it saying don't run before filling etc.
I'm a mechanical engineer who designs/develops engines for a living and really should know better.
Anyway it seized after about 5 minutes running, but after cooling down and filling with oil it started up fine - I thought I'd get a few hours used out of it and resigned myself to needing to rebuild the engine - fresh bearings and maybe new crank, but not at all - it's still going strong 6 years later.
These small engines are pretty lightly stressed and if you're lucky it will be just fine - might have a shorter life but something else will quite likely break first !
Hahaha markwsf, pretty much the perfect consolation post! Fingers crossed I still get a good life from the engine...
I popped the spark plug out, squirted a bit of penetrant in, left it for 5mins then put a socket on the drive pulley (only 75mm so no leverage by hand). With a bit of gentle force the piston moved. I topped up the oil, cycled the piston a few times then put the spark plug back in. It fired up after a couple of pulls. Did 5 mins of trimming before deciding the neighbours wouldn’t really appreciate the noise at 21:30! Will report back if it dies again soon!
Thanks for all the support/kind words/abuse! #themowerofprayer
Woot!
Keep and eye on it for blue smoke/burning oil, if it doesn't smoke or smell of burning oil you should be fine with it.
If it's any consolation I ran an MX-5 with no oil.... that didn't end well.... fire just off the M60 which I had to put out with my drinks bottle.
Felt really really stupid as I'd thought the week before that I'd better check the oil levels, but it got cold so decided to put it off the weekend before I killed it. Wife wasn't happy...
I now check oil levels in everything, regularly.
Glad you've sorted it!
Steve
Result!
Well done OP 👍
sharkbait
Even if the piston/bore are screwed you just need a new piston and bore…. not difficult. What engine is in it?
It was only run for a few seconds without sufficient oil, so that's what I'd look at doing.
But first I'd pull the head, and free the bore - a block of wood and a substantial tap should do the job after a good soak with oil.
Then pull off the cylinder and rub down any raised spots with fine emery paper - basically a polishing job.
Do the same with the piston. The idea being to remove any bits that have galled.
Flush the piston and cylinder a clean with petrol, oil it up and check there's a smooth sliding fit.
Check the spark plug for aluminium deposits and clean them off, and then check the spark.
Reassemble, and it almost certainly will run ok.
If it makes clanking noises then the big end is buggered, but that's unlikely in the time frame you quoted.
Shouldn't take more than an hour.
I can't add anything to this except to say 'good thread'. I enjoyed reading it and glad it all seems okay.
I think a few photos of STW's favourite miracle lawn mower are in order.
I made a shrine.
On another note, never store a lawnmower like this, all the oil will be draining past the piston rings and into the cylinder!
I love a story with a happy ending. 🙂
I can’t add anything to this except to say ‘good thread’. I enjoyed reading it and glad it all seems okay.
+1
And now I want to take an old petrol mower apart to see how they work (having never done such a thing).
It’s a lawn mower, they are pretty simple and robust and might be easily fixed.
If it had test oil it’s probably had enough lubrication to prevent too much damage.
Let’s be positive about this rather than saying his new toy is dead.
There wasn't many of us that had any faith. Hi five me! 🤣
Glad it worked out. Just keep an eye out for leaks
And now I want to take an old petrol mower apart to see how they work (having never done such a thing).