Background: I bought my 425 five years ago with 643 hours on it. The previous owner had a Deere dealer replace the plastic cam gear with metal, as well as new valve tappets and push rods plus an oil change and filters. Since then I've just filled it with gas, checked the oil, and run it. It now has 790 hours.
Last winter it developed a real reluctance to start when cold. This summer, in the warm weather, it has started and run just fine, and I had promised it that I would give it a good tune up once the season was over.
A week ago, in the middle of cutting the grass, it just plain quit. Gas tank was 7/8 full. Wouldn't start. Then I got it to start with starter fluid, but it would die once the fluid ran out. Then I got it to start and keep running, and I went back to the grass but it quit at full throttle a half dozen more times and sometimes would start up again after cranking, and sometimes would demand starter fluid to start. It got through the lawn and went into the garage and this time I REALLY promised it a tuneup.
1. Any opinions and/or guesses on the quitting at full throttle problem?
2. Any opinions and/or guesses on the very reluctant to start on a cold day problem?
3. What should I do for a thorough tuneup? I'm not a motorhead, but I figure I should be able to do it. Anything beyond new plugs, oil filter, oil, fuel filter, air filter?
4. What might be a good idea to replace as preventive maintenance?
5. Is it best to buy parts from the Deere dealer or is there a good online source?
It's been a great little garden tractor and we use it for a lot of stuff. The headlights and tail lights don't work (tail lights aren't even there) which doesn't bother me, but the temperature and fuel gauge don't either. Fuel gauge is no problem because I can just take the cap off and look, but I wish the temp gauge worked.
So, to summarize, I'd like to fix the problem(s) and do a thorough tuneup and preventive maintenance session - what parts should I get and install?