Battery for ST12

Hello evryone,
I have a 74 ST12 that I bought last year, spent a lot of time working on it but have always had a problem with the battery. I bought a new everstart worked fine for a while, now even after charging it, it won't turn the engine over, thought it was a starter problem but took it off today and it's fine, put new cable on to starter cleaned all connections, just clicks, I put a jumper cable on the starter from my 77 jeep j10 truck and it spun great and the bendix moved fine,
Do I have the right everstart on it? or could I use a small car battery? It has 225 CA, the truck is 600 cranking amps.
Any help would be appreciated,
Dan

The new batteries available for lawn tractors do not seem to be able to pump out enough amps the start the older Sears tractors. Notice the battery mount is much larger than the size of any new battery you can purchase for the tractor. When starting mine from cold, I roll the engine backwards until it is against compression to let the starter get 1 1/2 turns of momentum built up before it hits compression going the other way. I also never try to start the engine with the throttle much over idle. My starter/battery combo will not turn the engine past compression with an open throttle.

The engine spins over much easier when warm, but I still roll the engine backwards to ease the load on the starter.

hello fundybay this is telemon1 I have a st 16 so when I got my battery I went to the most cranking amp.
the CA is 350amp an it turns over fine. my tractor is a 1973 st 16
tecumsh eng. Hope this helps

Stop at a battery shop and have them do a load test on that battery. Sounds like a dead cell.