I just connected a Garmin Zumo with a powered mount on my 04 Superglide. I tried to connect the wires to the battery terminals and ran into an issues while closing up the battery area. The area the battery goes seems to be very tight with very little extra room on top of the battery. As I raised the battery box with the bolt, the positive terminal grounded out against the frame. It started smoking and by the time I got the box lowered down enough I completely melted the positive terminal to a melted blob of lead. So much for the new battery I installed last season. Luckly I did not damage anything else. Finally I connected the wires to the battery tender wires instead. GPS went from being a $350 unit to a $500 unit after replacing my battery.

 

Caring a motor I pulled to where my engine stand sat, I got a cramp and quickly set it on the bench not quit to the stand. When I lifted to take it the rest of the way I saw A sat it on top of new chromoly pushrods and managed to bend three of them.

also remember increasing the travel for rollers in old sifton blocks. Weeks later one cracked and split where I clearanced it… also once kept clearancing rocker arms in the shovel rocker boxes to the point where it was so thin that the chrome bubbled up once it got hot (in my defense it was a 630 lift cam in a shovel… you heard that right.)

 

​​​​​​ I'm going to keep right on saying it . Torque wrenches are dangerous .

 

I forgot to put the drain plug back in... twice. Dumped a bunch of synthetic oil into the drain pan both times.

Changed the fuel filter on my fuel injected Road King. Forgot to plug the quick connect fuel line back in and got pissed off because the bike wouldnt start. It took me about 5 minutes of cussing before I figured out what I did.

Edit- another time, I was changing plugs and wires on my Sportster. Working in my shed, there wasnt a lot of room to move around and I accidentally bumped the bike into gear without realizing it.
When I got the new plugs and wires installed, I reached up and hit the starter. The bike shot across the floor and banged into an old dishwasher I had against the wall. Put a nice gouge in my front fender.
I will say that HD really nailed it when they designed that kickstand, that bike slid about 5 or 6 feet on its kickstand and never fell over.

Edit #2- When I was about 10 or 11 I had a DS80 dirt bike my grandpa bought me brand new. It was literally a week or two old when I noticed there was about a half inch of slack in the chain.
Me being the genius child I was grabbed some wrenches and set to work tightening the chain. I made it as tight as I could get it, as in zero slack at all. I thought the tighter a chain is the better. So I rode the bike for a day or two until the chain and sprockets wore out.
Then I had to explain to my grandpa why my 2 week old dirt bike needed new sprockets and a chain. He wasnt happy, but he did take the time to show me how to properly install the new parts and adjust the chain.

 

When changing my cams last year I pinched one of the O rings between the lower push rod tube and tappet cover, I knew when I fired it up that I don’t have an oil pressure problem. Mobil 1 was everywhere . “You’re a ****ing meathead” that’s what my brain told me…yup !

 

A couple years ago when I was finishing assembly on the 107 in the Road Glide I installed the umbrella valves upside down. That made for a interesting first 30 seconds of an initial start up. I had oil running out of the pushrod tubes. Thought I had ruined a fresh build.

 

I probably have thousands of stupid things I've done to my bikes, over the years. You name it, I've probably done it.