Just an FYI thread about Bad Boy mowers that have a Vanguard 36HP motor. I have a 2017 Bad Boy Outlaw XP, with the Briggs Vanguard motor. It never cranked over in a way you would call strong since it was new. Dealer looked at it once, couldn't really do anything without Bad Boy support, and, well, their dealer support is non-existent. The factory refused to acknowledge there was an issue. But that is a whole different topic. They refuse to acknowledge any of their issues, in my experience.
After year two, it would no longer start, so I replaced the stock 300 garden CCA battery with a 550 CCA automotive battery, rechecked all the connections, and, it was better. For about 6 months.
Then it went back to slow cranking, or, turning over a half a stroke and stopping against compression, or, just clicking, and not even trying to turn the starter.
After testing about everything between the battery and the starter, and finding no issues, I assumed I'd have to replace the starter. Pulled it all off the mower, and took apart the starter.
Ended up finding a couple of things.... #1, there was corrosion on the plates in front of the field coils in a few spots, and, more annoyingly, there was paint spilled on half of at least two of them, from the factory. Hard to say how much this might have impacted the starter performance... but I cleaned it up before I put it back together, and lubricated the very dry bearings on each end of the starter. Bad quality control on the (surprise) Chinese starter on the Briggs motor.
#2, ran some contact cleaner through the starter solenoid. It didn't seem to be pulling in like it should, when I was bench testing it prior to cleaning it. After contact cleaner, it worked a lot better. Which lead to:
#3, it turns out that Bad Boy didn't wire the starter the way it should have been for the motor (surprise, surprise). The way they wired it - main current goes from the battery into the starter solenoid. A wire goes from the same lug on the starter solenoid, up to a relay somewhere, which is tied to the key for activation, and then back to the engage input on the starter solenoid. Bad Boy underwired this, and they were not delivering enough current to maintain a proper solenoid engagement. So, what would happen, is you would hit the key, and it would either not pull in the solenoid enough at all to engage the starter, or, it would hit, engage the starter, which would pull down the voltage on the input side of the starter, pulling down the voltage to the relay that was supposed to keep it engaged, which would then drop it. Leading to the solenoid dropping, or just being partially pulled in as this happened rapidly. Over time, this likely burned / dirtied the points inside the solenoid, making it get worse and worse.
The contact cleaner through the solenoid seemed to help with the solenoid itself. The fix for the Bad Boy wiring issue, was to get another automotive relay, and take the wire that was coming from the Bad Boy harness and use it to drive the relay. Then take a proper sized wire direct from the battery, thru that relay, and down to the starter solenoid. This keeps proper voltage on the engage trigger for the solenoid, and pulls it in hard enough to deliver proper amperage to the starter.
My dealer gave me the hint about the relay - turns out, he has now had at least 4 of them out in the field with this same issue. And multiple people at Bad Boy corp still refused to acknowledge the issue. Until one day, he managed to talk to someone at Bad Boy that actually has a clue - and he just mentioned as an aside - oh, yea, we put together a retrofit kit to fix that issue. Which is nothing more than a relay and some wiring, which they sell for way to much money to fix an issue they caused by not wiring it to the spec of the motor in the first place. All you need is a $10 automotive relay and some wire.
TLDR: If your Vanguard 36HP motor won't start like it should: Pull the starter off, and run some contact cleaner through the solenoid. Then, rewire the engagement circuit with a relay so it gets proper voltage and current direct from the battery. I did mine with 12 Ga wire and a 20 amp fuse. Spins over like a top now, even at 40 degrees. Previously, even when it was new, I'd have to open the free-wheel valves on at least one of the hydro pumps anytime it was below 60 degrees or it wouldn't turn over.
Its rather sad, how Bad Boy manages to build a pretty decent mower at a good price point, but then refuses to have any sort of proper customer support, or fixes for their known problems. I mean, seriously. We contacted the factory folks about my specific mower, for the starting issue. They provided no help at all. They finally realize the issue later, and 1) don't tell their dealers about it, 2) don't follow up with customers they know have the problem, and 3) don't even offer the cheap parts kit for free, much less at a reasonable price.
