Bigger tires is actually going to hurt your torque on hills. Bigger tires will help your flat ground speed, not uphill speed.

Nearly 17 years at a Yamaha & ezgo dealer as tech. Factory training for both.

Have you probed them with a volt meter? If so, what were the readings? If you wanna fix this yourself, you're gonna need to take voltage readings & understand them.

They look to be installed & wired correctly. What do you mean by "reverse polarity"?

What is the current battery pack voltage?

Or how many codes are triggering the check engine light.

Plymouth Sebring. A car so bad they had to change the name because everyone knew not to buy it. So, also Chrysler 200.

Mushroom cap... just the tip, I swear.

If your dealer knows how, they can tweak the programming in the controller to get you 25mph. But, they may not want to, because it's definitely not an ezgo approved modification.

Official specs for a PTV is "not more than 19.5mph", and for a LSV is "not more than 25mph". Also, it doesn't go faster down a hill by design, it's working as designed. Your cart is classified as a PTV & only goes 21 because you have larger than stock wheels.

Plug = NGK BPR2ES

No need to get some fancy plug, it won't solve your problem. I've seen many carts come off 4 years golf course duty with the original plug & running fine.

Same, that's what it's best for these days. With a little bit of NAS for fun.

Oh yes, there's a bunch of different china ones. You can't get parts, service manuals, or anything. Just stay with "the big 3" - ezgo Yamaha & clubcar.

The older westerns were built on a ezgo marathon chassis, the serial number should be stamped into the passenger side frame rail just above the front half of the rear leaf spring.

Actually, this one looks more like a ezgo TXT chassis.

At my work, they build nests on the underside of the roofs of the vehicles I work on. If you don't notice they are there, they drop down on your lap & they aren't happy to see you.

They NEVER ask for anything "very politely". But, if they did, I might reconsider. Maybe we can cut a deal on home security service.

One year a while back, it was a "boom year" for those giant grasshoppers with orange on the back of their heads (maybe locusts?). The bushes in my back yard were full of them bastards. Then the Mantis crew showed up & started decapitating them & gorging on them, it was glorious! The Manti were so fat, it looked like they would explode. I don't even know how they ate so much.

Yes to the first 2, the third was "any POS we could keep on the road & didnt break down too often".

Does "had a Commodore 64 before NES" count?