Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision

threefivezero

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Hey Folks,

I have a very old (20ish years) Craftsman rider with a 12.5hp Briggs engine that's hammering like crazy, presumably a rod knock. The engine is the original, never rebuilt.

Doing some basic google searches it looks like I can rebuild it for $100? And by rebuild, I mean very basic stock piston/crank/rod/gaskets and only hone the bore. Am I in the ballpark here? It's otherwise 'good running', meaning, it has run fine for years, needs no carb work, etc etc.

Anything decent on Craigslist, as far as I can tell for a replacement mower, used starts at about $400. I have less than an acre lot and I'm not a lawn care fanatic, I just want the grass shorter and I don't care what the mower looks like.

So I have 2 questions:

1) Can I rebuild it for $100, assuming I can do it myself? (Old car guy here, just rebuilt another Chevy 350 so internal combustion engines are old hat, just never done a lawn mower engine.

2) How many hours am I looking at to pull it apart, rebuild it, and put it back together? The longer I pay for lawn care, the more the 'true cost' of rebuilding it climbs. How long would it take YOU to rebuild it?

Thanks!
 

jeff

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Number one: If you have rebuilt a chevrolet, then this should be simple for you. You will need the specs and some way to hone the cylinder, a ring compressor, etc.
Number two: This depends on a lot of things, but I would think a competent mechanic should use four or less hours on the rebuild not counting the time to remove the engine.
 

threefivezero

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Number one: If you have rebuilt a chevrolet, then this should be simple for you. You will need the specs and some way to hone the cylinder, a ring compressor, etc.
Number two: This depends on a lot of things, but I would think a competent mechanic should use four or less hours on the rebuild not counting the time to remove the engine.

Thank You Sir!

I have a hone and ring compressor... I guess as long as there aren't any special tools unique to this engine I'd be ok.

Did I understand your signature right that you're a shop? I guess when I google, I find like a bajillion places to buy parts. Car stuff I know where to buy that's reputable and whatnot. Can you quote parts for me for this engine? If I can do it for $100 and in a single weekend I think I'll save it...
 

ronbo77

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Hey Folks,

I have a very old (20ish years) Craftsman rider with a 12.5hp Briggs engine that's hammering like crazy, presumably a rod knock. The engine is the original, never rebuilt.

Doing some basic google searches it looks like I can rebuild it for $100? And by rebuild, I mean very basic stock piston/crank/rod/gaskets and only hone the bore. Am I in the ballpark here? It's otherwise 'good running', meaning, it has run fine for years, needs no carb work, etc etc.

Anything decent on Craigslist, as far as I can tell for a replacement mower, used starts at about $400. I have less than an acre lot and I'm not a lawn care fanatic, I just want the grass shorter and I don't care what the mower looks like.

So I have 2 questions:

1) Can I rebuild it for $100, assuming I can do it myself? (Old car guy here, just rebuilt another Chevy 350 so internal combustion engines are old hat, just never done a lawn mower engine.

2) How many hours am I looking at to pull it apart, rebuild it, and put it back together? The longer I pay for lawn care, the more the 'true cost' of rebuilding it climbs. How long would it take YOU to rebuild it?

Thanks!



how long do you think you will be living at your home? because it would be a good investment to buy
a good top brand mower than to rebuild . your time and aggrivation ? or just hop on and get 'er done?
 

jeff

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Thank You Sir!

I have a hone and ring compressor... I guess as long as there aren't any special tools unique to this engine I'd be ok.

Did I understand your signature right that you're a shop? I guess when I google, I find like a bajillion places to buy parts. Car stuff I know where to buy that's reputable and whatnot. Can you quote parts for me for this engine? If I can do it for $100 and in a single weekend I think I'll save it...

You could try jackssmallengine.com and if you wanted to drive to Monmouth Illinois, I could help.
 

jteuban

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Yes $100.00 sounds about right. I would rebuild if the block is not cracked, and if the mower does not have a history of burning a lot of oil I would not re-bore well unless the cylinder is scored due to lack of oil or low oil. If you look on ebay there is a kit for you that is just around 100. So yes go for it, it would be a fun weekend project. Like I said take the engine off the mower and pull the crankcase apart, and if there is no real damage to anything including the cam do it. cheers
 

hoehappa

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
I would scrap
 

KennyV

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Do it... not only is it FUN... but you know everything else is good and you will have a Great working old machine that you have been working on...
If you can't enjoy doing a small engine rebuild... then I guess all that could be left is, setting around watching TV... (that would kill me)... :smile:KennyV
 

threefivezero

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Do it... not only is it FUN... but you know everything else is good and you will have a Great working old machine that you have been working on...
If you can't enjoy doing a small engine rebuild... then I guess all that could be left is, setting around watching TV... (that would kill me)... :smile:KennyV

Lots of good input there, thank you Kind Sirs!

I think I'll rebuild! It was using maybe 1/2 a quart of oil per season (6-8 months here) and honestly it ran strong and fine until last time I mowed. Just started knocking a little, then a little more, then vibrating so bad it finally died. It will still start back up but shakes and vibrates badly.

Does the connecting rod have a replaceable bearing like an automotive engine? What is the risk that the crank is damaged?

I currently rent but am in the process of buying the home I rent/live-in. But, as much as I'd love to have a new mower, it took me nearly a year to scrounge up enough cash to put back together the aforementioned (Camaro) 350 and that was something I really really really wanted! I'm 2 years post-divorce and I started over with less than nothing so... credit isn't in my near future either. Plus I'm now 'single income 2 kids' so... even $100 for parts will have to come out of my May paycheck. *sigh*

So while this is strictly a financial decision, (if I can fix it for $100 I *have to* fix it) I also totally dig Kenny's point above, I hate sitting around and I have to always be busy. The fact that I've never rebuilt a mower engine is all the more reason to do it! My kids are 7 and 10 now and over the winter they helped me rebuild the Camaro engine and put it back in the car. The 'skills' part of doing that kind of thing as a family is possibly arguable, but I'm finding that the older they get, the more 'top secret insider info' I get out of them when we're doing something together like that. So it's a win/win.
 

threefivezero

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  • / Craftsman Rider 12.5hp Briggs 286707 Junk or Repair Decision
Hey guys... long time no mow!

I limped through last summer with a $60 craigslist push mower and tonight I finally took the time to strip down the rider engine that I posted about in this thread.

The counterweight is what came apart. The piston, crank, and rod all look great. So, I'm thinking, a rebuild kit plus those pieces.

Thing is, the counterweight and associated 'wrist' thing are in so many pieces, it's not clear to me how they went together or what the counterweight is connected to. Any suggestions on where I'd find some photos that would help? I have the factory manual that has the exploded diagram, but the problem is that mine is exploded too! I need a 'completed' diagram!!!
 
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