I have a B&S 21hp Intek 407577 hard cranking

[adhill93]

I have a 21hp intek that is on a dixie chopper zero turn that i was gifted by someone tired of messing with it. Issue it that it is very hard to crank, as if there is way too much compression. I know the decompression valve on the cam, I have changed a few of them, I know the valve adjustments, have tried this also. What I dont understand is that it has the same cranking power with spark plugs in or spark plugs out. So, in my mind that rules out the decomp valve, correct? It does have a new 300cca battery and a new starter. Out of aggravation, I have also jumped straight from my truck to the starter with the same slow cranking results. I am open to any and all ideas you can give me at this point.
As it "cranks" (read as slow turn) it does make a hard to describe noise as the crank rounds a certain point. Something between a prolonged mouse squeak and the sound of an iron lung.
The belts have been disconnected also, as I though perhaps I had the PTO clutch froze.
I am at the point of re-powering it with a kawasaki, but at the same time hate to give up and let myself get beaten. That's why I'm calling in the reinforcements.

 

[ILENGINE]

Could be just a junk starter, but could also be caused by the magnets coming loose from inside of the flywheel.

 

[sgkent]

water logged rusty bore or what ILEngine wrote. You can use one of these to look in the bore. https://www.amazon.com/Endoscope-Inspection-Waterproof-Semi-rigid-Compatible/dp/B09TGRHTLK

 

[bertsmobile1]

And lets not rule out the chance of the engine having ben run low on oil so the crankshaft has an alloy build up on it on either the big ends or upper & lower bush.

 

[Tinkerer200]

And lets not rule out the chance of the engine having ben run low on oil so the crankshaft has an alloy build up on it on either the big ends or upper & lower bush.

My thoughts exactly.
Walt Conner