OutdoorEnvy 1,401 #1 Posted May 27, 2021 Hey folks! Decided to put the real love into this Lawnboy 10520 Gold Series mower. I picked it up at a garage sale a while back and am liking it more and more as I use it. When I got it it wouldn't start and the starter rope was frayed really bad and was short as it only pulled out about 3 feet or so. So I initially cleaned the carb and gas tank, it hadn't been ran in years of course. Also replaced the start rope and it came right to life. It's been fun and a pleasure to use. I see why folks are so high on them. So the "other" things I read on servicing are the exhaust ports and the gear box. The 3 speed transmissions on these are really robust and reliable so let's keep it that way for another 30 years! This one still shifted well through all gears. This was just maintenance. First is getting to the muffler which is under the deck above the blades: Take off the blade assembly and you will see this: remove those 3 screws and the muffler will come off and you will be here Now what you are looking for is checking the exhaust ports, you should see 3 round openings. If they are being blocked by carbon buildup that is what you are cleaning. If you do need to clean them make sure the cylinder is down next to the ports so carbon can't fall into the cylinder. Mine were clear but if they weren't I was going to use a small plastic scraper and have the shop vac running next to it to quickly suck up the carbon as it is broke loose. I cleaned some of the carbon off the bottom base. then just put it back together Next is the gear box for the transmission. It's the cover plate you see on the rear axle that you will remove. I did run the mower out of gas before doing this. You either want to lay it upside down or on it's side. If you do it on the side note the gears can drop out if you are not careful, so don't pull on them when you are cleaning if you don't want to remove them. I did this on it's side. grease was just starting to hardened up a little but was still soft enough it was working and I didn't see any damage to any gear teeth or anything. Cleaned out the old grease as best I could while being careful. packed in new grease then put the cover back on and you're done! Not a complicated job at all but probably the two things that don't get done enough on these mowers. I found where it is recommended to check the exhaust annually. The gear box I couldn't find a change interval. But this is almost 30 years old and it looked like a good time to do it. So once or twice a lifetime maybe isn't bad at all. Now it's ready to be a main worker in the fleet! thanks for looking! 1 6 Share this post Link to post Share on other sites
WHX?? 46,700 #2 Posted May 27, 2021 Nice work! @Stepney and @Gregor are LB fans 1 Share this post Link to post Share on other sites
Gregor 4,838 #3 Posted May 27, 2021 That 3 speed transmission is what got me started on Lawn Boys in the first place. My wifes Lawn Boy, which we bought new in '93 quit moving on it's own. I told her I would go looking for a new mower.THAT was a mistake. She liked the mower and wanted it fixed. NOW Long story short, there is a roll pin on the drive shaft in the trans that sheared. 13 cents, and my wife was happy again. Now I am Azz hole deep in Lawn Boys. The only difference between yours and mine is the bagger attachment on the handle. Be careful. Lawn Boys are like Can't have just one. 2 3 Share this post Link to post Share on other sites
Stepney 2,314 #4 Posted May 27, 2021 She's looking good now.. that mower will outlive us all. Run good oil and carbon will never be an issue again. I have just about the same model, just a little older, and with a self starter. I've had about every version of LB built from the late 40's into the mid 2000's.. an F series Pro 3 speed is still my go to. 2 Share this post Link to post Share on other sites
seuadr 488 #5 Posted May 28, 2021 muffler under the deck - that is kinda interesting. Share this post Link to post Share on other sites
Handy Don 10,563 #6 Posted May 28, 2021 16 minutes ago, seuadr said: muffler under the deck - that is kinda interesting. As a result, when running right, they are freaky quiet. You like having your neighbors running them! 1 Share this post Link to post Share on other sites
seuadr 488 #7 Posted May 28, 2021 1 hour ago, Handy Don said: As a result, when running right, they are freaky quiet. You like having your neighbors running them! i do like freaky quiet mowing Share this post Link to post Share on other sites
EricF 589 #8 Posted May 29, 2021 The really freaky thing about Lawn-Boy motors, even the big M-series ones, is that they tend to be noisier at idle or light load. Once they're working into a proper load and the governor kicks in, they smooth out into that classic, subdued outboard motor hum. Completely different beasts from chainsaw and trimmer engines, as well as four-cycle power. 2 Share this post Link to post Share on other sites
