Cranking Issues GVX670

[bigbyrd]

Greetings. I have a 2005 Hustler with a Honda GVX670 (24 hp) engine that has not given me any problems until recently. Usually after mowing, I park it under a tree until I can blow all the debris off with a leaf blower. Recently when I went to restart it to park inside barn, it acted like the battery is dead. The fan and oil pressure light comes but starter does not work. The first time I removed and charged battery and checked all connections and it appeared to correct problem. Yesterday, however when it would not restart I left it sitting for a couple of hours to do something else. When I later checked to see if it would start, it surprised me and started up. While I had it running, I checked the battery voltage, it was 12.80. After shutting off engine, I checked battery voltage again, it was 12.20. I am wondering if charging system might need some attention. I have no idea of how charging system works in this application.
All responses appreciated.
Robert

 

[tomplum]

Well, the first place to start is get the battery loadtested, which by the way many auto parts stores do gratis. A minimum of 250 CCA. Clean the terminals on the battery and using a multimeter perform a draw test. It the simplest form, hook the meter between the - terminal and post. More that a couple tenths or so of a volt could be abnormal. Draw test instructs can easily be found online to advance you down that path. With the machine running, use the multimeter to the battery posts and any voltage plus the base voltage of the battery shows that it is charging. Your battery is 12.6 volts not running and 13.5 running, it's charging. Much over 14.5 and it may be over charging.
Other options could be a starter that is getting tired or valve lash that should be set. Let us know what you find and things you hear and don't hear when it fails if need be.

 

[bigbyrd]

Thanks "tomplum" for your response. Saturday afternoon I tried to crank it again. It cranked although somewhat sluggish, the volt meter reading was 12.7 while running. I turned it off and tried to crank it again. It would not crank, and the volt meter reading while trying to crank was about 5 volts. Two weeks ago when I had the (nearly new) battery checked at Walmart after being fully charged, they said battery was good. I am going back to have them check it again tomorrow (uncharged). Just to satisfy my curiosity, just how does the charging system work on a lawn mower or other small engine?

 

[tomplum]

The magnets in side the flywheel spin around a stator which produces AC current. Then on the way to the battery, the 2 AC lines pass through a voltage regulator/ rectifier and out it comes as DC current that the battery can use. There are some variations. but that would be your Honda's set up. When running @ WOT and your meter set on DC, you will be able to tell if the system is working if described above. You can also set your meter to AC and will normally get only a trace reading. Batteries don't like large doses of AC. Should something seem awry with the test, we'll have to dig up the shop manual if your regulator is one of the 6 pin versions.

 

[bigbyrd]

Thanks tomplum for the info on lawn mower and other small engine charging systems. Update: I hooked up battery tender Sunday afternoon. Today (Monday) about 10:00 a.m. I had intended to remove battery and have it checked again at Walmart. However I could not resist seeing if it would crank. It did and then cranked the next 4 times I tried it. So I mowed some grass that did not need mowing to get it at operating temperature. I then parked it and killed the engine. It cranked just like always the next 4 times I tried. My neighbor showed me how I had been reading volt meter incorrectly. It now shows 12.8 volts when not running and it slowly climbs to 14 volts when running. When cranking the volt meter shows 10.5 volts. I wonder if I was not following the correct procedure when having these cranking issues. I like it when something like this heals itself, I just don't have any confidence in its durability.