420 Help?

[mccann316]

I just got my 420 and have used it for a couple of hours, I would say the undercarriage is in excellent shape and is supposedly almost new everything. So far I have had the following problems:

1. Dozer would quit when hot, filed the points and this seemed to solve the problem.

2. Starter locked and I had to unbolt and turn back and now it seems fine. Does anyone have the old crank to start in case this happens again, I would be interested in buying?

3. The most major and current problem is the govenor seems to have broken. All of a sudden the dozer reved up really high, I of course shut it down immediately and checked, all external linkage seems to be intact, what is inside the motor, how do I remove it, any ideas what happened, how much it will cost?

I will be getting the manuals, but until I do what motor oil should I run in it and where, what type of filter does it have?

Thanks for the help,
Ryan

[Lavoy]

Ryan,
Quitting when hot sounds like a bad coil. Is the crawler converted to 12 volts, that will burn points if the correct coil is not used, or a ballast resistor put in.
When the starter locks, you can not break it loose with a crank, trust me. Only way to do it is just what you did. New starter drive and bushings may cure the problem.
Sounds like the fly weights on the governor are bad, or the bearing went out. Pull the governor off, and take a look at it. Not sure if the new parts are available any more, I have used on hand.
Lavoy

[mccann316]

Thanks for the reply Lavoy. Yes the dozer has been converted to 12 volts, what do I need to check for and where can I get the correct parts? Approx. price? Also, how hard is it to pull the governor apart? I haven't looked at it at all? Is it easy to get too, pull apart outside or should I get it inside? What are the approx. prices on the parts?

Thanks,
Ryan

[Lavoy]

Ryan,
You will need to use an internally resisted coil, should say "For use without resistor" or something like that on the body. Part of the starter binding is due to the 12 volt battery, the starter engages a lot faster than it does on 6V. Also may have increased wear on drive and ring gear from 12 volts as well.
You are almost going to have to pull the radiator to get at everything. Pull the hood and air cleaner first, then you will have a better idea of what you are up against.
Be sure that you are careful when pulling the actual governor shaft and weigts out, there is a bronze thrust washer against the block that might fall off and end up in the pan, and yes I know this from experience.
Unless you have damaged gears or somthing like that, should not be over $100 to fix.
Lavoy

[mccann316]

I looked into the 12 volt conversion, the coil on the machine has 12V stamped on it but it also looks like there is a resistor in the line. It is a square piece with two small wires going to it. I took the govenor apart and it looked fine put it all back together and have used it 2 hours since and it ran fine. I don't know what the problem was.

Thanks,
Ryan

[joe420c]

Another reason for burning the points may be a bad alternator that over charges. The amp guage should settle down to close to zero (maybe 1 amp) after running a while. Check the voltage at the alternator and coil. Shouldn't be more than 14-15 volts.

Joe