, I can walk out and she fires right up no problem so it's staying until it declares itself dead!
Richard, What is the availability of the onans that you recommend? Availability/price of parts? And what time frame were those engines produced?
I would fix the CCKA. If the PO hosed up the end of the crank, there are ways to repair that.
A new stator should not touch the crank at all.
Availability of a P224 or P220 really depends on market conditions. Since you are in Boomers neck of the woods, I would think that they are fairly plentiful.
Parts availability is good. Part prices are cheaper than a similar Kohler Magnum. The most I paid for a P224 was about $600. That was a nearly pristine very low hours engine. The other P224 engines cost me $150, $250, and $350 plus time and gas to go get them.
Taken care of, almost any engine will last but I have never seen anything like the P224 from my 24G that I tore down. After nearly 3000 hours the only thing worn were the piston rings. A new set of rings, a quick honing of the cylinders and some new gaskets and seals and it is good for another 3000 hours or so.
The other Onan P224 engines I have ran fine so I never bothered to even measure the bores. The rod bearings looked good so I just put in a new crankshaft. The original crankshafts in those engines were the wrong length and diameter for a Gravely which is why I had to replace them. The cranks that I pulled out had zero wear or scoring. I have no idea how many hours there are on the other P224 engines I have.
The CCKA that is currently on my son's 8123 tractor came off my 816. The 816 was scrapped when the transmission failed due to abuse. When I tore the engine down almost 20 years ago due to smoking, the only thing worn on it were the piston rings. I honed the cylinders, put in new set of rings and that was it. That engine is still running fine today.
If you do decide to put a P224 on it, the extra power will spoil you. To be honest 24 hp is overkill on a 800/8000/G tractor with a 50" or 60" deck. Overkill is underrated.
As with most things, YMMV.
The big plus in your case is the fact you have the Onan adapter plate. That makes a replacement with another Onan a slam dunk. Bolt the adapter on the engine and slapthe engine on the transmission. No messing around with custom parts, ordering thrust bearing washers, etc.
The other plus is the exhaust system for the replacement Onan. A very nice stainless steed, mandrel bent exhaust system can be made easily. Unless you happen to like the plumbers nightmare/water pipe look, stainless is easy to fabricate. A hacksaw and a 1/2" wrench is about all the special tools needed. If you have a long tail hood, you will likely need a sabre saw with a metal cutting blade to turn it into a late version.
Most of the P224 engines have a voltage regulator bolted to the engine so that makes wiring it easy.
I would rather do three Onan engine transplants/upgrades than one Honda repower. I would be done quicker.