I Rebuilt My YZ125 In A Closet!?

It was more like a hallway, but the work area was still smaller than I wanted. I picked up a 2003 Yamaha YZ125 that had some major frame damage. The bike ran well but was not ride-able. The two options were to scrap the main and sub-frame, or take the time to bend and weld them back to their somewhat original form. Either way I would have to strip the entire bike down to the very last bolt and tie-strap. Just by looking at it I could tell this was going to be a difficult, yet exciting project.

I got to work tearing down everything on the YZ125, starting with taking the engine out of the frame. There were a lot of nuts and bolts from the plastics, engine, radiators, frame, and other miscellaneous parts that I had to organize into little zip-lock bags so I wouldn’t lose track of where they went when I put them back on the bike. In the middle of this process I got the sub-frame bent back and welded so that it would fit like normal. Being me, I decided to go the more challenging route of getting the main frame welded instead of paying a couple hundred for another one. Once I took everything off of the main frame my dad helped me by welding it.

I wanted to make this bike look good when it was finished, so I sanded and cleaned off the main frame to get it ready for painting. It took a while, but I managed to find some paint that was close to stock color shade. I then painted it with a few coats to make sure that it wouldn’t peel or chip right away.

Tear Down Process
Tear Down Process

The rebuilding process began just after the paint on the frame dried. This is the part where I had to move everything inside…. I started with the foot-pegs, front-end, rear shock, and swing-arm. Those went on pretty easily, so I then took the whole engine and bolted it up to the frame. The rear-wheel and handlebars with controls were next to go on. After that it was just the electronics, carburetor, plastics/tanks, seat, and a few miscellaneous things, such as the exhaust system.

Rebuild Process - Frame painted, front-end, rear shock, and swing-arm on
Rebuild Process - Frame painted, front-end, rear shock, and swing-arm on
Rebuild Process - Engine in, rear-wheel, handlebars on
Rebuild Process - Engine in, rear-wheel, handlebars, and controls starting to go on

After working inside for some time, this project was well worth the outcome. In the end I think the bike looks good, and I learned quite a bit more about rebuilding these modern dirt bikes (Check out my other article, “How I Built A YZ250F With A Box of Scraps” if you liked this one). Let me know what you think, and if you want to see more projects like this just give me a shout. Thanks!

-Tom Stark

Finished '03 YZ125 Project
Finished '03 YZ125 Project

How I Built A YZ250F With A Box of Scraps

What do you get with a bin full of dirt bike parts and an eager mechanic looking for excitement and satisfaction? A great project rebuild! If you are a dirt bike grease monkey like me who not only likes riding their bikes but sometimes working on them too then this is for you. I enjoy project rebuilds and love the oh-so greatly anticipated finished product even more. Ever since I got into dirt biking I have gained more knowledge about how they work and how they are put together. So after doing many rebuilds myself I thought that I would share the experience with you fellow riders.

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I bought this 2003 Yamaha YZ250F in pieces as a project bike thinking that I would have some fun and get some more experience putting another bike together over the next month after I bought it. It came needing a complete new top-end at the least. I managed to get one and put the engine together in a reasonable amount of time. I then slapped the engine in the frame and started the process of puzzling the rest of the bike back together; this is where the fun started. It only took a few short minutes of bolting parts on to find that there was stuff missing. The more I put together the more parts I found that were missing or broken, and they were not all at the same time. So one-by-one I had to buy parts that I needed to piece this thing back to its somewhat original form. These parts consisted of, including engine parts, clutch plates, radiator shrouds, timing chain, timing chain slider, a different piston, head pipe, a couple crank bearings, engine/frame mounts, air filter, cylinder head breather hose, chain, gas tank, clutch perch assembly, a shift lever, and maybe a couple other miscellaneous things. Figuring out that we had to find and buy these parts got a little frustrating because we were told that the bike was complete and that it just needed a new top end.

Well, after weeks of picking at my wallet this bike has finally been put together and is running. It just needs a couple things put on to be ride able. So once I get those together I’ll take it out for a spin. The process was long and somewhat miserable, but I think I learned a lesson and gained more experience and knowledge about these modern four strokes that basically took over the world. In the spring, if not sooner, I will be putting on some new bling to make this baby look new, but as of right now it’s a clean bike that runs. Thanks for checking out this rebuild process, and make sure to check back in the near future for another bike rebuild! (If you liked this article make sure to check out my other rebuild, “I Rebuilt My YZ125 In A Closet!?

-Tom Stark

P.S. I might update this article with some pictures and/or video once I get this bike looking good. Questions and comments are welcome.

When I got the bike (as you can see, I had my work cut out for me):

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Pic of the damaged cylinder head:

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After I cleaned it up and the engine was together in the bike:

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Put the wheel and handlebars on:

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The bike put together (added sub frame, carb, electronics, old plastics, seat, exhaust, cables, etc.):

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The finished product…

 

Motocross Practice Track

Hey guys, just wanted to give an update on my racing/riding life. A few days ago I went with a friend to his friends’ house and rode there for the second time. It was an all sand track, so it was a bit difficult for me at first to jump everything. It was in their yard, so there wasn’t a whole lot of room to get up to speed. There was a real nice whoop section, a fast and sick woods section that winded around the house, then you go back and do a few more whoops with a double-table-top after that. To finish it off was the most fun section that was a pretty long stretch with three decent size doubles. Overall, I had a lot of fun once I started jumping and doing all of the obstacles. It was great practice and will definitely help me in the future. I might be heading out there again tomorrow, so I might give another update for that if anything interesting or funny happens. I also have a supercross race coming up next Friday that I hope to go to. I will for sure post info about that, so don’t forgot to come back every week or so and check out my profile. Thanks for viewing!!

My Friend's 250F
My Friend Digging Up Some Sand
Friend Hitting The Double
Friend Wheeling Over The Whoops
Friend Roosting Some Sand
Looking Back Over The Double
Showin' Some Style Over The Double

Dirt Bike Racing – Jordan Supercross

Race

This was my first race at the Jordan Supercross

track promoted my Motokazie. It was at the Scott County Fairgrounds in Jordan, MN. I raced in 125 C class and ended up finishing 13th out of 20. There was one kid in my class that had a really bad accident and was down on the ground from the first lap until the end of my race…… Did not look too good.