OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines B&S 12.5 HP I/C Quiet, exhaust valve retainer.

Thanks Rob, they ended up being the cotters, glad it wasn't the pins by the sound of it.
I will use grease to hold the split cotters when I put it back together, good tip.
I don't have a compressor tool.

Grumpy that makes sense, supply and demand for the BS rings. I must admit that my starting point for the small Briggs engines is good compression, otherwise it is a waste of effort.

I have some images: Not exactly sure how to proceed from here.


Carbon found in the intake port.


Not sure what to make of this, casting broken away around exhaust valve guide.


Scoring around the top of the piston, on the valve side that matches scratching in the bore. No scoring found on rings.



With timing marks aligned piston was travelling back down the bore. Bit different to what Ive seen with the smaller engines.