Need some experienced electrical help with my S650G.......

[Necrid]

Hello all. I have a S650G Satoh and seem to be having some electrical problems with my tractor and since I'm not the best of mechanic I was hoping I could get some help looking in the right direction. A couple of months ago while using my tractor on my driveway it suddenly died and hasn't started since. I thought it might be the ignition coil since it seems to eat them for snacks, but after changing it, it still would not run. I checked the distributor for a spark but nothing. It was then I noticed that the points was messed up and would not open, so I put in new points, rotor and distributor cap and still no spark. I then got a new condensor and put on with no spark. I checked the ignition coil again after trying to start it a few times and it would be hot enough to burn to the touch. So I went further back tracing the wires to the voltage regulator and replaced it since it too was bad. It was then I was finally able to get a very faint spark in the distributor but not enough to start. The coil would still get hot. I noticed the battery cables were getting so hot that it melted the clamps on the terminals and replaced the clamps. The starter has been rebuilt as well. The only thing I haven't changed is the battery itself and the battery cables which have some burnt marks and rusted naked wires like this....

I also checked other wires for broken or naked wires and could not find any. I'm not sure what else to do or look for. I would really appreciate any help or guidance as this is the first tractor I've owned or had to try and work on.

 

[Ilikeurtractor]

The only thing I can think of is make sure you have a good ground on the battery to the frame/engine and same with the negative pole of the coil. I've been working on diesels so much I kind of forgot all the details of the ignition system on a spark ignition engine. Sounds like you pretty much addressed everything though.

 

[Necrid]

Thanks and I will double check that. I did check different spots with a multimeter for the voltage. Seems it's right around 13 or 14 until I try to crank and then it drops to just below 10. I think I will replace the battery and the battery cables just in case.

 

[Ilikeurtractor]

10V during starting is about typical from my experience.

 

[Xfaxman]

Thanks and I will double check that. I did check different spots with a multimeter for the voltage. Seems it's right around 13 or 14 until I try to crank and then it drops to just below 10. I think I will replace the battery and the battery cables just in case.

Before you do that, why not find out what the problem is? It is called troubleshooting. Watch this video: Starter Voltage Drop - YouTube

Read this page: Car Battery Tester - How to Test a Car Battery

It says car, but tractor battery is the same.

Then fix your problem instead of throwing parts at it, you may never fix it that way.

 

[Utah Bison]

OK I will try to help but internet diaginsos is hard because i always have more questions.
What you need to make spark is positive voltage to the + side of the coil. The - side goes straight to the distributor. So with that being said put your meter on the - side of the coil(red lead) the black lead to good ground or - battery. Take the distributor cap off and with a small screwdriver open and close the points. Open points voltage should be 12 or battery voltage. Closed the voltage should be 0. The points ground the negitive side of the coil collapsing primary windings inside the coil and making it spark. The condencer is used to absorb excess currant when the points open so its a clean switching. Now all this being said if open points do not increase voltage on coil - the wiring or bolt /insulator to the distributor is staying grounded causing excessive heat in the coil and no spark. It it stays at battery voltage the points are not grounding the coils -. Either poor ground of distributor case or inside breaker plate. Theres a small ground wire inside the distributor that goes from one of the point screws to the distributor body and it must be there and intact or the points can't ground properly since the breaker plate isn't grounded enough.
The heated battery cables may be from just poor connections at the cable end and excessive cranking testing for spark. I would replace the positive cable with a real one not the quickie fix ends.
I hope this helps and didn't just confuse you more.
Good Luck Lee

 

[LD1]

Yep. No need to crank for testing spark. Just open and close the points and watch the coil for spark.

Also, you said you replaced the points, what did you gap them at?? Do you have a manual?? Points are adjustable, and if they arent right, no spark.

 

[Necrid]

Thanks I find all this info interesting and helpful, I'm enjoying learning and working on this. I will try out what you all have suggested. As for the points I'm not real sure. My brother who works on vehicles often and knows better than I do put the points in and set. I didn't question him cause he usually knows what he is doing.

 

[Utah Bison]

A couple of more suggestions. These tractors do not use a ballast resistor to the coil. That is used to lower the voltage at the points to slow arching and extend point life. When replacing a ignition coil, one with a internal resistor is advised so it wont eat coils and points. Another thing is the condencer outer case must be grounded for proper operation. I have seen someone wrap it in black tape to make it fit tighter in its holder. Causing very weak and erratic spark.
Again good luck LEE

 

[Necrid]

Ok I tried checking the voltage from the battery all the way up to the distributor. The meter shows the same amount of voltage all the way through but nothing past where the ignition coil -post connects to the distributor. The bolt sticking out from the distributor looks a bit rusted. Will try cleaning that up to see if I get any results.