Tractor starting problems

Discussion in 'Shop Talk' started by Randy Rooster, Aug 8, 2006.

  1. Randy Rooster

    Randy Rooster Well-Known Member Supporter

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    I have an older Belarus tractor that has always been difficult to start on the electrical side of things. I have found loose wires here and there over the years, but a new problem is that when I turn the key I hear a click in the solenoid and the cable running to the starter gets hot, but it takes several attempts and me thumping on the starter with a 2x4 to get her to turn over slowly- she always starts if I can get her to turn over. I just replaced the batteries with new 2 months back and keep them charged up. Any suggestions are appreciated. Please dont tell me to get rid of the Belarus as it isnt an option at this point. Could it be the starter or the engine seizing up? Im not much of a mechanic.
     
  2. rufus

    rufus Well-Known Member

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    I'm not sure what other people think about your brand of tractor but most tractors are pretty easy to work on. As long as you make sure that your oil pressure is up were it should be your engine should be alright. What I would do is take apart your starter and see what looks broken. If nothing seems out of order, clean everything and put a dab of high temperature grease in the bearings/bushings but I am willing to bet that you need new brushes. The starter on my van did the same thing, wouldn't start unless you smack it a few times with a hammer. When I took apart the starter, I noticed that two of the brushes were longer than the other so I went to the electric shop and for $14, I got the whole brush assembley (avoid auto parts stores if you can. I got my parts from a side business of John Deere where they rebuild generators, alternators and the like.). Ask where you get your parts how one would go about holding the brushes back when installing, they are usually really helpful. Make sure your comutator (end where the brushes ride with narrow long copper bars) doesn't have any burs and that there is indeed a space between each and every one. Copper is pretty soft so a pocket knife will clean out the seperations. LIGHTLY sand the commutator with the finest sand paper you have to clean and brighten the copper. If there are gouges or really bad spots you can use a file or sharpening stone but if you use such course tools you really should chuck the whole armature in a drill press or lathe if you have one so the end product won't end up with flat spots. I would say that once you have the starter off you will have maybe 1/2 hours work to fix/repair.
     

  3. moopups

    moopups In Remembrance

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    Old tractor? 6 volt or 12? If its a 6 volt system it is usually the ground strap, yes - strap. 6 volt systems need a massive pathway to the ground, at least twice the size of a 12 volt, that is why a woven steel strap is the original issued ground connection.

    Is the solenoid a part of the starter or a separate device? If its a separate device you can cross the two major connection studs with an insulated wire to detect if the solenoid is malfunctioning. If the starter engages via the bridge of wire then look to replacing the solenoid.

    Some systems require that you bridge between the hot lead in to a lessor size connector post in order to respond, each system is different.
     
  4. Randy Rooster

    Randy Rooster Well-Known Member Supporter

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    Thanks for the suggestions guys. It is a 12 volt system but runs off 2 large 6 volt batteries run in series ( or parrallell) to make the 12 volts.

    Where does the ground strap or cable run to or from? Im pretty ignorant on mechanicals.

    Im going to try the simplest things before trying the starter take apart.
     
  5. Ross

    Ross Moderator Staff Member Supporter

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    We had a Belarus for years and years, two for a while. An 820 and a 420. Tough simple tractors, they can be tricky to work on. Only ever rebuilt the starter once and yours sounds like it needs it. A few things to try. You could clean all the electrical connections including the steel to steel connection between the starter and the frame. The other thing it could be is the negative battery disconnect switch. They fail even though they seem to still click on. $15 part a few years ago. That tapping the solinoid makes it work (slowly) means it's more than the grounding.
     
  6. chuckhole

    chuckhole Born city, love country

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    Check the Batteries:
    Assuming these are servicable batteries, remove the caps. Take a volt meter and set it to DC voltage. Place the black negative probe down into the battery electrolyte at the negative post (cell #1) and place the red possitive probe down into the next cell (cell #2) and read the voltage. For 12V batteries, it should be 2.2V. Write this down. Then place the leads down into cells 2 and 3 record the reading. Then go to 3 and 4 and then 4 and 5 and then 5 and 6. Each of the readings should be within 10% of the others. If one of the readings is low, you have a bad cell in the battery. Rinse the probes of your volt meter off with water when you are done.

    Check the Connections:
    Remove all of your battery cable connections and clean all of them with a terminal post cleaner or wire brush and reassemble and try to start your tractor.

    Test the Starter:
    A way to test your starter before dissasembly is to remove it from the vehicle and place it on the ground. Connect jumper cables to your battery and a negative lead to the starter at one of the bolt holes and tap the possitive start lead with the possitive jumper cable. The starter should kick out and spin with such force that it tries to flip over on the ground. If the kick-out and spin is weak, then it needs work or replacement.

    If it is not the starter, then you have a power problem between the batteries and the starter. Check the possitive and negative cabling for damage and corrosion.
     
  7. Randy Rooster

    Randy Rooster Well-Known Member Supporter

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    Again thank you everyone for the help. Can the cable running to the starter turn bad because of corrosion, even if the wire feeding into the terminals are clean?
     
  8. Randy Rooster

    Randy Rooster Well-Known Member Supporter

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    Ross said "The other thing it could be is the negative battery disconnect switch."

    Is that the push button that powers up the electrical stuff ross?
     
  9. PyroDon

    PyroDon Well-Known Member

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    Id start with new brushes in the starter and double checking all cable connectons for currosion . feel the cables if they are getting hot the starter need a quick rebuild brushes and bushings .
     
  10. Randy Rooster

    Randy Rooster Well-Known Member Supporter

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    I dont know if this is the end of the starting problems, but Ross"s comment about that battery disconnect switch sounded like a possibility I could work on easily enough- I took the switch off, disconnected the cable which runs to the negative side of one of the batteries and cleaned up all the connections and connecting bolt and nuts and washers on the switch, put it back together and she turned over and then started up faster than shes done in a long time. Knock on wood Im keeping my fingers crossed, but keeping everyones suggestions in mind if I have further problems. Thanks for all the help!

    Ps this is an AS 250 Belarus about 15 years old.
     
  11. Ross

    Ross Moderator Staff Member Supporter

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    They are great switches but they crud up inside too so keep an eye on it. We were stumped for electrical problems until we changed it, and all magically disappeared with the new switch. A blast of WD40 seemed to help the switch for a while.
     
  12. Ross

    Ross Moderator Staff Member Supporter

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    My 420 was very similar. Those 250's have scary pulling ability for 25 hp!!! Does it have the engine decompress lever?
     
  13. Up North

    Up North KS dairy farmers

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    Randy the Belarus are not a bad tractor "for the money". They are economical on fuel consumption, and one of the lower priced tractors available with MFWD. Loaded many round bales in deep snow with them. The only beef I had with Belarus was I had a heck of a time learning Russian, LOL.
     
  14. Randy Rooster

    Randy Rooster Well-Known Member Supporter

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    Yes Ross it does have the engine decompress lever- never used it- what is it for?

    I like the tractor and have had it for about 8 years. Once you get it to turn over she always starts winter or summer. Electrical problems are their weak point in my opinion.