JD 650 last call

   / JD 650 last call #11  
randy741985,

I had a 750 for 18 years which is basically the same tractor (sold yesterday).

I never counted the seconds, but would hold it in the left hand position until I could hear a distinct poof (fuel igniting?). It started no matter how cold it was out and it stayed outside under tarp for months before being used again. It was a great tractor reliable tractor.
 
   / JD 650 last call #12  
The thermostart system depends on both fuel and electricity for proper operation.Over time,especially with contaminated fuel,the thermostart plug can become "plugged".My 650 had this problem when i purchased it.After disconnecting the fuel line,which was cracked,i flushed it out with penetrating oil.A brown goo came out.I let it soak overnight,and replaced the thermostart tank and fuel lines next day.I manually filled the thermostart tank with fuel,and after putting the engine through a few start/stop/restart cycles,the system began to function.Actually,if you listen really closely,you can hear a "poof" in the intake manifold when the fuel ignites.It's actually a very reliable system.You can almost set your watch by it,so to speak.15 seconds and "poof".
 
   / JD 650 last call #13  
Resurrecting this old post as I now need a wiring diagram for a 650 seems mice moved in under the dash over the winter and they moved out leaving it non operational Your help would be appreciated!
 
   / JD 650 last call #14  
See my post #4 above - except the link in that post is now broken. (Wow - that was 10 years ago.)

Here again is the diagram I linked. It is a similar size Yanmar of about the same year as your Deere. I hope the diagram is similar enough to your Yanmar-built Deere to get you started on your repairs.

Added: This diagram includes an ordinary automotive alternator and regulator. If your Deere has the little pancake 'dynamo', driven by belt or inside the water pump hub, then the charging circuit will be different.

31855d1104721271-1610d-volt-reg-wells-vr728-557466-yam240elec-gif
 
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