Starting and Maintaining a Twin II

I was reading a lengthy thread on another forum about no starts/ slow cranking with the Twin II engine. There were a lot of people commenting on slow starting issues. Also my Murray widebody is now over 20 years old. I think there may be some different ideas out there on keeping these old mowers in service. Getting back to the slow cranking, I found relief from the problem mainly by upgrading to an automotive battery, a Ford style solenoid, and larger battery cables. However, someone on the other forum found satisfaction by just upgrading the cables to larger ones and running a ground cable directly to the engine block. I noticed the oem cables are small. It is possible the most important thing to do is upgrade to larger cables if there aren't other issues causing the problem like a weak battery. There are other issues that can effect starting, I had to replace the coil module on mine. I noticed there was a lot of corrosion on the spark plug connectors on the old one. Also, I think using iridium spark plugs is helpful for easier starts. Regarding general maintenance, for years I was using straight weight oil, but more recently I have been using a blend. I am mixing straight weight oil with Mobil 1 V-Twin 20W-50 motorcycle oil. I have had noticeable performance improvements since I started using the mix. I have not tried using just the Mobil 1. Back to starts, on cold starts I use a battery charger with an engine start function to assist. I remove the air filter and spray starting fluid or pour a little gasoline in the carb. On warm starts, I just start the engine on battery power alone... no issues there.