Briggs & Stratton 21hp platinum engine hard to crank and knocks!

[keakar]

I'm 99% sure I reinstalled it, but that is a possibility. Thanks for your input!

but did you confirm smooth operation of the oil pump itself?

its not uncommon after an engine failure for aluminum transfer to the pump gears and they dont turn to pump and just spin as a complete lump not pumping any oil

i see no way to avoid going back in at this point because you need to stop guessing and find out for sure whats knocking

next time buy a used mower with a bad deck and good running motor of the correct or larger hp size for $100-$150 and be done with it

repairing an engine that had a major failure is never a good idea because very often things like this happen after you have put good money into them

 

[EngineRepair15]

but did you confirm smooth operation of the oil pump itself?

its not uncommon after an engine failure for aluminum transfer to the pump gears and they dont turn to pump and just spin as a complete lump not pumping any oil

i see no way to avoid going back in at this point because you need to stop guessing and find out for sure whats knocking

next time buy a used mower with a bad deck and good running motor of the correct or larger hp size for $100-$150 and be done with it

repairing an engine that had a major failure is never a good idea because very often things like this happen after you have put good money into them

Thank you for you input! Everything was turning smoothly when I was assembling the engine.

 

[EngineRepair15]

I found the problem. The compression release mechanism failed(which is why it was hard to crank) and some of the metal from the compression release chipped a tooth off of the cam gear(I think that's what was causing the clicking/knocking sound. Also, since the gear tooth broke off, it slipped a little which through the timing off a little and I think that's why the engine was shaking, because it was firing at slightly the wrong time. I hope I'm making sense.

I inspected the whole engine and nothing else is damaged.

Thank you for all your help!

Jeremy

 

[StarTech]

And ACR failure are common on the 793880 camshaft as it can happen at anytime.