Engine Engine won't crank. Do I have a couple problems?

[KyGolfer]

I have a Scag Wildcat Zero Turn- 27hp Kohler engine. Model CV740S -- This ran fine 2 weeks ago. Now, my problem is that it won't crank. When testing the battery, it's coming up short at just 10volts. Only 10volts to solenoid too. The solenoid barely clicks once. I get several clicks coming from instrument panel, but it then stops. When I attach a jump starter to the battery, the solenoid goes nuts with clicking, and the motor will try and spin, but not enough to turn over. Do I have a bad starter? AND, a bad battery? What are the odds of both going out at same time?
You guys have helped me out a lot. I very much appreciate it.

 

[ILENGINE]

I would start by either charging the battery and see if it will charge up. If not then replace it. When you put a load on the battery it is most likely dropping below 10 volts. The minimum voltage to engage the solenoid is 9 volts, so that isn't anything to play with.

 

[bertsmobile1]

If a fresh charged battery works, then check the voltage at the battery with the engine running fast.
It should be around 13V with a fully charged battery going up to 14 V with a flat battery.
So take a voltage reading,motor off ,motor running then motor off again.
The running numbers must be higher than the stationary numbers.
If not check the earth strap to the rectifier. They oft break or the bolt falls out.

Anything more specific will equire the mower model number & the engine brand & model number.

 

[KyGolfer]

OK! You guys are the BEST! After reading your reply's, I decided to go out and take a battery off another mower I have and switch it to the Scag. Yep, kicked right over. I never knew that using a jump charger would give the mower too much voltage. On my "Yard Machine", ( the one I cabbaged the battery from) I have used the jump charger on it very often, with fine results.
Anyway, after spending a Sunday afternoon tearing brackets and instrument panels off the Scag looking for a bad circuit, I'm glad that the battery was just the culprit. Still better than having a repair shop tell me that it was a starter, a solenoid , and a battery! Ha. ( Not saying they would, but you never know.)
Again, Thank You Guys! I'd buy you all a beer if I could.

 

[bertsmobile1]

Before you get too excited, take those voltage readings.
Jump starting does not get too much volts, don't know where that comes from.
There was a reason why the battery went flat in the first place.
Pop the "bad" one on a charge and see if when charged, it holds that charge for a week or two before you toss it.