1872 Blowing Solenoids

[GWRdriver]

Out of the blue my 1872 has just blown two starter solenoids. Here's the sequence:

Running fine until I stopped for gas. On restart engine won't crank and the solenoid clicks and buzzes. (Battery is fully charged.) Pos(+) batterly lead is very hot (perhaps from too many attempts to coax solenoid to work.)

Checked starter and battery cables for shorts to frame. Checked starter for operattion - it's OK. Replaced solenoid and the Pos(+) battery cable (it was in need of replacement anyway.)

It restarted and ran just fine until I stopped the engine. Then on attempted restart the same above sequence happens except that this time the Neg (-) battery lead is hot. (Nope I did not reverse any wire connections.)

Any clues on what to look for before I start pulling things apart?

 

[bwmarine]

Bad starter drawing too many amps

bad connection - battery cable - ect... getting hot from not being able to carry load

bad battery low voltage

 

[GWRdriver]

New battery (this season) fully charged, new #4 gauge battery cables. The starter seems fine although I haven't put an ammeter on it yet. I'm still perplexed, but in the meantime I'm going to have a look at the Bad Boy ZT-60.

 

[Bob_Bainbridge]

You said the positive cable was hot and you replaced it. Then the negative cable got hot and later you said the cables were replaced. Did you in fact replace the negative cable also? If not I would try that. You might try measuring the voltage at the starter while cranking and then at the battery posts. If the voltage at both points is going very low, like 9 volts or so, either the starter is drawing too much current or the battery is faulty. If the voltage at the starter is more than 1 volt lower than the voltage at the battery posts you have bad cable(s) or connections. Make sure you are probing the battery posts themselves and not the cable ends.

Bob B.

 

[jimdiesel1]

Also check that the engine turns over as it should when hot, not that it has a mechanical issue. With key switch off, put a wrench on the electric clutch retaining bolt after shutdown and try to turn it; if it turns unusually hard it can be an engine issue.

Second thing, insure that the starter pinion does not stay engaged when running; a solenoid mis-wired would cause this, as would a failed key switch. If the starter remains "engaged" when the engine is running it is being "motored" by the flywheel the whole time you mow. Think this way, if the starter cranks the engine ~800RPMs imagine how fast it spins when the engine is spinning at 3600 rpms! Oh, the pain! I have seen M-18/20 starters remain engaged while running from dirty key switches etc, it does happen. Let us know what you find.....

 

[bwmarine]

New battery? Check the fluid in the battery... one guy on the forums that I have read buying a new battery and they never put the fluid into it. Basically trying to run on a dry battery.... and of course starting issues