Your moto wrenching mess ups.

1990 KX 250, never tightened the damper rod nut to the fork cap after changing to heavier springs. Nuts backed out and major damage, forks almost separated tubes. Luckily there was some kind of recall on those forks that year, first year  for USD. My dealer got it warrantied. But cars, on the other hand, I've got tons of those stories.

When I was in high school I was doing a clutch on my CR125. I drained the oil and put the plug in hand tight thinking “I’ll definitely snug that down before I ride it”. Did the clutch, filled it with oil. Raced a hare scramble a few days later, about an hour and a half in the shifting started getting funny, and I heard a click from somewhere near the countershaft sprocket every once in a while. Nursed it in for the last half hour, went back to camp and loaded it in my buddies van and camped out all weekend. Got back to his house, opened the back door to the van and was staring eye to eye with the gaping hole of where my drain plug was supposed to be. 

Replaced the top end on a bike, spun it over, all felt good. get on the bike, kicked it over ran like shit. Started thinking how in the world I fucked this up. Started stripping the bike down to see what I missed and spotted the culprit. The damn wash plug. 

 Not me buuutttt:   Someone brought a bike over for me to do a rebuild on. Ofcourse, its still dirty. Take it outside and wash it, see a chunk missing from the crank case. Call him and tell him whats going on, so he orders it and brings it over, in the meantime I carry on with the rebuild. Transmission was shot, you name it, terrible shape. Get it mostly together, waiting on the part and he brings it by saying he needed it back by tomorrow, with part in his hand, 1/4 impact in the other, both eyes redder than a dog dick and could smell weed on him from twenty foot away. He goes over to the work bench, puts it on and goes straight for the impact. You guessed it, cracked it.  I was pissed. Got everything right eventually, and ofcourse, never got paid. 

Tire changes- either success or failure.

 Had a storm coming through, and wanted to get my wifes car in the garage. I keep my truck in there, and all I have to do is move a couple bikes around and no problem. I had three bikes at the time, which was a new challenge, but knew just where to put the third. I grab the bike to swing it around, and I guess I wasnt aware of how close I was to my truck, but the rear fender karate chopped the front fender of my truck and creased the shit out of it. I almost puked. 

In my roadracing days I put on a new front master cylinder before the weekend.  Leading one of the races (there were like 4 guys in my class so don't be too impressed) I'm about to get on the brakes going into T1 after a long straight..but when I went to reach for the lever it wasn't there. I guess I didn't get the lock nut on the new lever tight.  So I proceed to lock up the rear trying to slow down from like 150 mph which was very ineffective and roll into the grass at a very scary speed. Somewhow I kept it up but a row of hay bales was approaching quickly so I used the rear brake to slide the bike out and crash myself.  As I'm tumbling through the grass I spot my lever also bouncing through the grass so I kept my eye on it until I came to a stop so I could retrieve it as I had no spare 😂 Somehow the bike didn't tumble. I think I had to replace a footpeg and handlebar and I was right back out there a few races later.  My buddy behind me thought I blew the motor because of all the smoke coming from my rear tire when I got on the brakes lol.  

I once put on the front number plate of my 97' KX250.  I put the throttle cable I think above the number plate bolt instead of under it.  I was working on something else when I put it back together so I rode it around for a couple minutes and everything felt good.  I then started pulling some wheelies and play riding.  I was in a 3rd gear wheelie when I counter steered to the right and the throttle blipps as it pulled the cable tight on top of the carb enough to open the slide.  I don't know how I saved it but I was dragging the rear break, probably about dragging the rear fender.  I got the front end down but I was sideways (at speed) and I started swapping side to side.  I was able to get the clutch in but for a swap or 2 the handlebars where clicking and the throttle was blipping.  It had to be a hell of a site.  

Losing a wrist pin circlip on the bottom end while doing the top end on my son's 85. We found it shortly after starting the engine. Embedded in the side of the cylinder... lol. 

Premixed with fork oil instead of engine oil. It ran for the whole moto but seized two turns from the finish. What was the worst part? I was in the lead..

Yall aint going to believe this shit.  We were kids, I was around 12 riding 80's and my neighbor was a few years older and had an 83 CR125.  We were Jonesing to ride and he had been waiting on a top end kit for like a week after saving for it for about 3 weeks.  Seemed like half the summer.  He got the kit and it took hours to put it in.  I was waiting on him to show up so we could go riding.  I hear him start it, warm it up and cool it down.  I knew he would be coming in about 10 minutes so I get all my shit ready.  I hear him start it.  He pulls up and I had a really big jump in my front yard.  I'm sitting on my bike, helmet on ready to go.  He rolls up the driveway, looks over and gives a nod.  He swings through the yard, hits the jump 3rd gear powerband and sails it.  I remember thinking the bike sounds great.  He lands and the throttle sticks.  He couldn't kill it because he didn't hook up the kill switch and he pulls in the clutch.  Its screaming and he dumps it and kind of throws it away when he bails off.  It stands up, wobbles side to side and it takes off, upright, by itself, for about 40 yards and straight up a high wall that we used to climb.  It made it up the high wall and sails about 10 foot through the air as it cleared the top and straight into a tree.  The front wheel looped right over a limb of a maple tree and the bike hung there for what seemed like 20 seconds before it grenaded.   Insult to injury, we had to cut the tree to get the bike out, 10 foot up on the top of a 20 foot high wall.  Front fender busted, rear fender busted, radiators busted new grips ruined and blown engine.

He was so distraught over the whole thing and there was no way he was going to get to fix it again.  Luckily one of our riding friends who lived near sold him an 84 YZ 250 for $400 and the CR.        

Worked at a shop , got a new Honda 125 (2000ish)  put new tires on it , went out to the back lot  and went thru the gears ,realized i never touched the brakes , went right under the fence at the end of the parking lot 

It's nice to read other people stories...you don't feel so bad about your own anymore!

Mine was I had loosen all the top triple clamps bolts because I wanterd to tighten the steering stem before going riding. Sometime during the process my neighbor drives in so we just start talking. I get to the track, unload the bike and do a lap or two to warm up . I come back to the pit thinking damn something feels weird with my front end. Sure enough I had lost 3 of the four pinch bolts on the triple clamp and my fork tube were compeltely uneven. Good thing I always do a slow sight lap without jumping anything even if it is a track I've ridden 1000 times.

When I was maybe 16, I decided to tackle a bottom end rebuild on my '76 Yz80C.  I don't remember what the problem was, but the cases were split, and everything disassembled.

I put everything back together, and had no extra parts, so I thought I was good!

Ran it down the street and it seized up!

The problem?  There's a small plate that holds one of the main shafts from sliding out.  It can be installed in one of 2 orientations.  I installed it rotated 180 degrees!

When I took it back apart, and this time had to replace a shaft and couple of gears, it was obvious that it went the other orientation.

Since I didn't get hurt when the engine seized, I'm still glad that I did the work myself.

My worst one that im not proud of at all. I was working for a factory rider and at Redbull Straight Rythm, in either 2015 or 2016 we made a fork change during the day. Rider goes out for practice and does a run or two and comes and says something in the front end feels fucked. Check some things out and find out I left the two caliper mounting bolts loose. They were hanging on by a thread, literally. I pride myself on my work and I cant imagine what would happen if the front caliper wrapped up in the front wheel there. Narrowly missed severly injuring or worse one of my friends and an incredibly good dude that day. Our crew chief who was an awesome man himself and someone i very much look up to to this day was like hey, we're human we make mistakes, but were only allowed to make the same mistake once and learn from it. Luckily that was an easy lesson to learn and not a much more difficult one. 

I was checking the valves on the second bike I ever owned and must have gotten side tracked but one of the buckets didn’t go back in…. Didn’t end well

Another one, I took an impact to the fork to remove the bottom adjuster. Well, you don't do that for a reason. Luckily Race Tech had individual Showa parts to get me going again.

Oh, and not me but a friend was friends with the McGrath family. He was able to buy the 1992 Peak CR250 that MC raced 3-4 rounds on back east. He said that bike was a beast. Lots of power that started out low. Well he decided to do a top end and put the piston in backwards. Which wrecked the cylinder when it hooked a ring. He bought a new cylinder, took it to PC and asked for the same porting MC got. When he got it back he could tell it wasn't the same and it didn't run the same. It was a mid and way up motor. 

Servicing an aer cartridge. Couldn't figure why the seal head was so tight. Then a massive pop and look up to see the cartridge rod shot through the ceiling.  Forgot to let the air out!

I belive to this day, if it had hit me in the face, I'd be dead. 

 09 crf450 drained the oil night before riding forgot to put oil in and it lasted about 10 minutes 

My dad was adamant about me working on my own bike. Early 2000s at an SRA Grand Prix at Glen Helen I took off  uphill on my cr80. Made it about 50 ft uphill and my rear tire pushed forward and the chain came off. Apparently I never tightened the axle nut after fixing my flat.  I was pissed because I was in 3rd and he laughed his ass off.

Doing top end on RM125 wasn’t paying attention and put the power valves in backwards (taper facing wrong direction). Started up and tick tick tick. What’s that?? Take cylinder off and 2 nice nicks in the piston. Back to the dealer to get new piston (dealer was awesome and stocked parts for my bikes). Service guy asked why I needed another piston so soon, do I need help with tuning(guy was super cool and always answered my questions - Randy at Ken’s sports if you are in WI, he’s probably retired by now…)Nah, I’m just an idiot 🤦‍♂️, but thanks for asking!  

The other was my brother would take us to the races as he’s older than me, so I would do the bike maintenance. I forgot to put the seat bolts back in after cleaning filters. His seat came off the 2nd lap of his moto, he was pissed at me! 😂

Did some work to my bike, including clutch work.  Fired it up for a test spin and it wouldn't move, like the clutch was stuck disengaged.  

Spent 30 minutes troubleshooting it and was getting desperate.  It wasn't until I happened to swing around the left side of the bike that I realized I had left the chain off!

I work at a dealership and had to bring my 2 year old with me to work one day. One of my managers was walking around and found chicken tenders sticking out of some of the exhausts on showroom bikes. There's no telling how many he got shoved down far enough that we never saw them. I had a highlighter go missing that day too lol

I've worked on bikes since early childhood and then my dad opened a shop when I was 12 so I have a lot of screw ups on stuff. I double o-ringed an oil filter on a customers GSX-R 750 once and when my dad took off to test ride it, almost highsided coming out of the parking lot. One time, a buddy I hadn't seen in a long time came over to get a tube put in his XR650 wheel. He stood there talking to me the whole time while I unknowingly folded the tube in half when I stuffed it into the tire. When I aired it up it exploded and scared the shit out of me lol

Building a Franken bike from a roller from OKC, engine from Australia, and various parts from multiple places. Got it running and was going to take a spin on it but right as I swung my leg over the radiator hose blew off the head port. Apparently I forgot to tighten the clamp 😂.

2006 KX 450, Just had the forks done and was reassembling everything.  Had no races coming up anytime soon so wasn't in any hurry and worked into a rhythm of a chug-of-beer and a spin of a wrench.  Got done and was doing a few compressions test to see how they felt.  They felt great, but noticed something else didn't feel right.  It was the bars, they were crooked, not bad but noticeable.  Had them for a while and had some get-offs with them but couldn't remember them being that out of shape.   They were used and I'd probably be getting a new pair soon.  So, I figured what the hell I'll get them wedged into something and slide a persuader bar over the grip and start tweaking.  After a while I'm thinking that should do it.  I'm standing at the side of my bike bent over looking across the bars, and then it hits me, the bars weren't bent, I didn't install my off-set bar clamps correctly.                     

Rode 60 miles during a sprint enduro without rear spacers. sprocket wore thru the swing arm. 

Let someone use my spare rear wheel , assumed they would swap spacers (Austrian ) to fit their bike , they actually rode a 60ish mile enduro with 22 mm spacers and a 20mm axle . No idea how He didn't feel it 

I've had a few over the years. Kicked my 1986 CR125 for a half hour, cussing it wouldn't start. Turned out I left a rag in the airbox.

Probably my dumbest was kicking my RM250 for a good part of the afternoon before realizing I had forgotten to put gas in it.

Once left my triple clamp bolts loose and did a practice session before realizing back at the truck. That could have been bad.

Onetime I put fresh tires on and went out in practice at Southwick and my bike was all over the place. I was shocked and wondered how it was so much worse. then i noticed the pinch bolts on my fork were loose and my rear axle had also moved, and I checked my pressure and I had 91 pounds in one of the tires!  Lucky for me, practice back then was sometimes only a lap, 3 at most. That was the last time I let anybody "help" me work on my bike when in a rush. We had both assumed the other guy tightened the parts that were not tight. Unless it was another prank by my buddy??  When I went out for my moto the bike was much better with the correct PSI in the tires and both wheels firmly attached.  

I think that's all of my blunders.  For some reason I think I may have had a circlip pop out from a piston on my RM250 at some point. But I'm not clear on that one. I would have been 14ish at the time.

did the same on an 87 YZ250. 

Not terrible damage wise but my ego hurt bad after spending 4 lunches at work trying to figure out why my fiancés freshly rebuilt crf150 motor was not getting fuel. Carb on and off, torn apart and back together at least 5x just for out lead tech to cruise over and start poking his screwdriver down the carb boot into the head while smirking and going "did you forget anything??"

I left a little plastic dust cap in the head, installed the carb boot over it and proceeded to tear my hair out for a few days waiting lunches trying to sort out my fuel problem, started right up after that. Damnit 

I was 11-12 and changed the oil in my rm85 and over tightened the drain plug stripping it out and cracking the case I never admitted to it just acted like I pulled over from riding and it was leaking.