Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)

NashvilleMatt

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  • / Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)
Hi Group,

This is my first post. I'm seeking some guidance regarding the feasibility of repairing a Briggs & Stratton 33R877-0009-G1 with a broken connecting rod. I opened the crank case and found a bunch of pieces (picture attached)

The piston and the bore appear to be okay. The bore does have a scratch/dent, but it looks like it's below the lowest piston position (picture attached)
However, the crankshaft appears to be scratched and dented a bit where the connecting rod attaches.

My questions are as follows:

1. Do you think I need to replace the crankshaft or can I file it or smooth it out?
2. Does the bore look sufficiently undamaged that it would hold pressure?
3. What else should I consider before I buy a new connecting rod?

Thanks!
 

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Scrubcadet10

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  • / Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)
Re: Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)

I think you'll definitely need a new crank. IMO
Not sure about the gouge in the bore. Might can hone the cylinder and put standard rings back in, but I don't know if that might weaken the area around it and make it prone to cracking.
 

bertsmobile1

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  • / Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)
Re: Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)

Clean the crank up by degreasing then dipping in Hydrochloric acid.
See what it ends up looking like.
More important is working out why the rod broke in the first place because if that is not fixed then history will repeat itself.
 

NashvilleMatt

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  • / Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)
Re: Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)

Clean the crank up by degreasing then dipping in Hydrochloric acid.
See what it ends up looking like.
More important is working out why the rod broke in the first place because if that is not fixed then history will repeat itself.

Definitely. I don't know the answer to this. However, it was very low on oil when I drained it. I was thinking maybe the piston seized due to lack of lube. Valves look okay...
 

NashvilleMatt

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  • / Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)
Re: Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)

After degreasing and cleaning with muriatic acid, it looks like there is some scoring on the crankshaft (picture attached). Does this mean that the part is garbage, or is it possible to clean it up?

IMG_20190907_124934688.jpg
 

Scrubcadet10

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  • / Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)
Re: Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)

toast. New crank and rod., I looked in the parts diagrams and no undersize rods are made.
Plus, most rods only go smaller to 0.010 inch. And from the looks of it, they look deeper than 10 thousandths.
 

Strommer

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  • / Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)
Wondering if anyone else has had same issue with broken connecting rod on these Briggs and Stratton 19HP motors? Just tried to figure out why my son in laws John Deere wouldn't start and when I was checking valve clearance, to get piston at dead top center, it did not move when turning flywheel. Connecting rod broke about an inch from the piston.
Only 100 hours on the mower. Not good.
 

StarTech

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  • / Briggs & Stratton 33R877-0009-G1 Broken Connecting Rod (Ariens 42' riding mower)
Broken on these engines is usually caused by run them too low on oil.

BTW another way of removing the aluminum transfer on the crankshaft journal is to use Muriatic Acid. Just got to be carefully as it is moisture sensitive and can produce toxic fumes so it must be used outdoors with the wind at you back. Once the crank is clean you neutralize the Muriatic Acid with water. Immediately dry the crankshaft and oil heavily.
 
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