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My First Lawnboy Repair

2692 Views 2 Replies 3 Participants Last post by  Burr Head
Some of you may have read this on another forum, but I thought I would share with the members over here as well. Also, this is about a Lawnboy, but it is for general reading rather than Lawnboy specific, so I decided to post it in this forum. Hope you enjoy.

Think about this mower often, as it was the first LB that I really did any work on as far as tearing into the engine. I couldn't tell you what model it was or what year. All I know is that it was pretty old when I got it, probably about 1997 or 1998.

My guess is that it was a mid '70's machine, probably a "D" engine. Something makes me think it might have even had a sticker that said mix the oil/gas at a 16:1, but that's a long time ago. My boss at the time had an old Lawnboy that he had used but one day it went "Clunk" and quit running. He asked me if I would want it, as he knew I had another Lawnboy that I used to mow our yard and a couple others on the side. I said, "Sure!". Like I said I had never been further into a Lawnboy than to take a blade off and sharpen and maybe take off the shroud and blow out the debris. Well, I got the old fella home and tore into it like I knew what I was doing. Got the carb off, so far, so good. Pulled the blade, then the muffler. Wow. There has to be some exhaust ports here somewhere, isn't there? Poked around and prodded a bit with a screw driver and finally broke thru one of the ports. Sure enough, there was the cylinder. Tore a bit more apart. Off came the shroud, flywheel, (hmmm, what the heck is all this stuff in here?), split the case. Pulled the piston out, with some extra effort. Wow. Tons of carbon in there. What had apparently happened was a huge chunk of carbon had broken off the piston, gotten wedged between it and one of the intake ports or exhaust ports, and gouged up the cylinder and piston very bad. (OK, now Indy452, if you are reading this you may want to leave the room cuz this is where it gets real bad.) I cleaned the piston up as best as I could with emery cloth, steel wood, etc... Got most of the gouges smoothed out so it wouldn't scrape as it traveled inside the cylinder. I borrowed a cylinder hone from one of the guys as work and started in on the cylinder. Probably only shaved the cylinder to about .015 to .020 oversize to get the ridges out of the walls where that carbon had been drug by the piston. Looked at the rings. Hmmmm, there's a fair amount left. May as well re-use 'em. It's not like I am going to depend on this mower for cutting my lawn or the side jobs. Besides, didn't hardly have to compress them at all. Used a bit of Marvel Mystery Oil to give the piston a chance to get set in place without making any more gouges. Started putting it all back together. That didn't go too bad. I think that most of the parts I had removed got replaced during that operation. Now comes the sweaty palm and dry throat time. Will it start? Will it stay running? Will I have enough time to get away before the piston starts flying across the driveway? Yes to all of those questions. Actually, it ran pretty good for the short time I had it running.

Anyway, fast forward a few months. My dear wife had not become accustomed to the color "Grabber Green" at that time of her life. All she could do was count to 2 and decided that there were too many Lawnboys in the garage or 1 too many wifes. (Rest assured, new members, if your wife is similarly intolerant, it will pass. Nowadays Linda can count up to 8, sometimes 9, before she asks "Do you think you should get rid of a few of those before you bring any more home?" I kid you not!!!) Anyway, my unsuspecting brother happened to stop by the house a short time later and I made him an offer. Yes, he would take the old Lawnboy off my hands. I told him up front that it might not last very long as it was the first refurb I had done on an engine and the one thing I knew was that I didn't do it right. He took it anyway. That was maybe 1998.

Well, the other day I dropped him an email and happened to ask when had the old Lawnboy finally croaked, or was it (yeah, sure!) still running. His response:

I've still got the old Lawnboy. I've never had a better lawn mower! Our grandson has been mowing the yard this year, so it hasn't got much use. However, I used it just recently, and after sitting all winter and most of the summer, it still started with one pull (Major complaint - I had to replace the starter rope, and after I did that the hard way, I discovered the easy way)!

I've been using Mobil 1 synthetic oil that I drain from my vehicles to mix with the gas for the last two or three years just to see what would happen, but it only runs better every time I start it. Want it back?
It just goes to show you, if you want it to last and work well, as long as it's a Lawnboy, it doesn't really matter if you do it right OR use the right 2 cycle oil. Sometimes they just won't die no matter how hard a life they've had!
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That was the good thing about the older engines or any equipment for that matter. It was overbuilt and designed as such you did not need to be a mechanical and or electrical engineer to fix every issue with it. Cars the same way. Basic mechanical knowledge of what was going on along with some common sense could get you back in operation.

I kind of look at the days 20-30 plus years ago as the days when your tool box from the trunk, a couple borrowed specialty tools acquired over the years by dad or your grandfather, some smokes and beer for assisting hands would get you through a lot of odd jobs. ;)

Now it's code readers, specialty tools to change even a belt or fuel filter, and a computer to search for any diagram possible that might help decode the interconnection of spaghetti and mysterious black boxes. :rolleyes:
I hope I have just as good of a success story as you. Like you know, and maybe some readers, my Lawnboy 7268 (from 1982) locked up. Dang, it's only 28 years old! I tore it down like yourself. The cylinder wall looks pretty good. I borrowed a hone from a co-worker and plan on honing it out. I look forward to getting all the part back together, and seeing if my old partner will fire up. It better. About 2 months ago, I just spent $7.00 on a new air filter! (I wonder in the 28 years, how many wheels I have went thru?) I'll be in touch. I have borrowed a mower from my in-laws to get me thru the final 4+ weeks on the season. (I just have to cut their grass also)
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