I installed a full sized 12V car battery and what could go wrong did go wrong.
It turns out that if the battery is run very low, then you jump start the vehicle and let it idle to recharge the battery, the higher amperage will fry things.
I found two plug in diodes and a plug in capacitor in the wiring harness (all ruined).
Linhai Bighorn 28, LH400CUV... have PDF's of the parts manual and schematic if anyone needs them. Diodes and the Capacitor aren't show on the schematic. , There is a [Rec/Reg] (Rectifier) shown on the A.C. Magneto, (I would think there would be three diodes if they just put those as separate plug in units). The Capacitor isn't show either, but a "protecter" is across the starter relay and the starter motor, maybe it's one of those?
If anyone has a little more knowledge about these electrical systems I'd sure appreciate it. I'm waiting on parts and I expect I can fix this, but having more knowledge would be a good thing.

 

Extremely doubtful that a bigger battery would overload the charging circuit. I guess the higher cranking amps may do something to a "protector" in the starter circuit. Regulators are usually finned aluminium boxes, and get hot, so are placed somewhere air can get to them to cool things.

 

Thanks. Wondering what these are for... Both of the bad ones are completely open in both directions.
Turns out, my plug in capacitor is fine (977 µF), (I messed up the test).

 

Can you send me pics of where it goes on the quad. I cannot find where it goes foe the life of me. Can u please email them to me.. much appreciated Deesthangz84@gmail.com

 

Capacitor mounted near brake cylinder.

 

On wiring harness, under the dash, Right Hand side of the CUV (left looking from the front). Hope this helps. I've been able to fix everything that could possible fail on this beast. The hardest find was a broken signal wire coming from the cam sensor at the bed hinge point. That was tricky. You can fix this.

 

The other

The second diode (identical) plugs into the wiring harness that runs horizontally behind the dash.

 

I got this machine over the weekend and I think I got the carb ready and just moved the wires in the battery box looking around being nosy and now I have no spark. Does anyone have any ideas or a wiring schematic I can get a copy of. I have checked all connections and can't see anything loose and I did have spark before this.

 

 

ty I just seen this today I thought I turned on notifications, I'm new here and new to these. I got this and I had spark and cleaned and adjusted the carb then all of a sudden I have no spark. I pulled the coil off and hooked it to my Honda 300 and the coil is good. The bighorn will turn over and all lights work but I have no spark. I'm electrical illiterate but I'm trying. Can anyone give me some advice? I did go through the whole harness today checking connections and rewrapped it.