YZ125 build - brake in 🔥🔥

hey guys this is our 2 stroke dirt bike build 2001 Yamaha YZ125 and we are very close to completion, in this video we are going to show you how to brake in 2 stroke dirt bike engine on our fresh dirt bike build!
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[@3BrothersExtreme]

This bike sounds amazing! Can’t wait to see the finished product with the rims, tires and graphics.

[@danpoxon2425]

What a sweet machine! Love it just finished a full rebuild on a o3 kx 125 it’s the best feeling in the world first brake In on a machine you’ve fully rebuilt it’s like all the hard work an attention to detail has payed off

[@dirtniron]

Congratulations Dan, great feeling for sure 👍

[@ToonedInn]

I’m building a 05 rn next week sending out the frame for powder

[@brianmorse8811]

Around 1980 I got my first bike a YZ 125. lost it in a barn fire a few years after, still miss that bike. I like seeing you guys rebuild these bikes.🤠👍

[@dirtniron]

sorry to hear that Brian, that would be a nice barn find for a build ;)

[@brianmorse8811]

@@dirtniron don't be, that place in my hart is not a hole it is a warm spot that doesn't need to be filled. Is full of joy and memories of Good times. 🥰😎👍

[@kNx2k14]

just bought an yz250 1993, i cant wait to get it to its original 1993 state

[@tomnekuda3818]

Rado - when I was racing Husky's back in the day I would do just what you do except I would break it in, take it apart and touch up the rings and piston with stone to get perfect seal. I might do this a couple of times but it was worth it in the aircooled days because of cylinder distortion. The distortion is quite repeatable so the attention that I gave it was well worth it. After I seized a Husky 390 XC with new rings and piston, I learned to always do this. Where the piston was tight, the finish would get shiny and that is what I would gently stone down that piston area and the fit eventually would be nearly perfect. I always made absolute sure that I set the ring gap where I wanted it before going hard on it. I'm now 76 and doctors have basically banned me from riding. Just had my left knee put in and, apparently; the Doc set the specs right on it as I'm not having any real problems. It joins the happy family of two replaced shoulders, replaced right knee, and four back operations. They always frisk me in airports. I enjoy and live thru you guys. Crazy as ever, Tom P.S. Going to sneak a bike out.....rained last night...... P.P.S. Listening to the Yam, sounds like the jets are tending toward being correct.

[@dirtniron]

haha, Tom you always crack me up! sounds like you knew your way around old school smokers, sometimes I wish I can be in that era of dirt biking for a while, golden era for sure. Did you consider side by side? age-cage.. that kind of thing, but still beats the couch! Take care my friend!

[@tomnekuda3818]

@@dirtniron Rado - Age cage ain't for this boy.......always hated 4 wheels......just too many to keep any eye on!

[@AdvSouthAfrica]

125cc is my favourite, they're so fun to play on!

[@dirtniron]

most fun bikes for sure!

[@gladegoodrich2297]

When I was young my brother told me something I've never forgotten. He said you love dirt bikes because your too dumb to fly jets. Not sure if he was right but at 77 years old, I still love my dirt bikes.🤗

[@dirtniron]

haha, that sounds about right ;)

[@rehepeks]

I fly jets but I still love dirt bikes.

[@rearwheelslider]

Jetting on such a rich oil mixture! You should jet with the mix you’ll be using.

[@Jakeserragarage]

Sweet video. First new bike got me here always had used bikes so never thought of it. I’m just going to ride that thing how I ride.

[@ShawnBlais]

Brake in, or Break In? Sorry, I don't like myself either :p

[@DoeMan777]

Bike looks fantastic

[@dirtniron]

thanks Marco, glad you like it!

[@_WebersWorld]

Now get that wr going!!

[@dirtniron]

yea, thats the plan!

[@dormantmenace]

I have a old 86 yz 125. Was the boys first bike. I ran it down the road with gps the other day. That thing did 71 mph with 14/48 gearing lol im 225pnds they are 6 speed thoe

[@dirtniron]

dude, thats fast! I think 86 year has the same colors, right?

[@dormantmenace]

Ya just gold rims.. that look so good lol I think they were only like 26hp that year. But it's actually a blast to ride just got to work the transmission over real good lol. It had a 50t but it just ran our if gear so fast. Kinda small in the cockpit thoe. And very light and unplanted.

[@noControl556]

After a top end I do more of a "did I break it" than a "break in" as In I just want to make sure the thing works by riding around my house a bit before I load it up and haul it down to the trails. How much "heat cycling" do you think the mx guys during the 2 stroke era did when they were doing top ends between motos?

[@derrickspells2264]

I’m rebuild a 1999 yz125 with original frame. I would love to recreate this also what was the recommendation from Tom Morgan on the main & pilot. Bike sounds amazing

[@TwoThreadsAhead]

Would 32:1 still make sense if someone was using regular unleaded pump gas ? Like a RON 95 on a stock head and piston ?

[@zardportugal]

NO black rims which to me is the best look. Great build.

[@dormantmenace]

All those late 80s red n white yz had gold rims thoe intill early 90s

[@dirtniron]

I wanted to get gold rims but decided to go with black, will look decent ;)

[@Jordan348_MX]

Do you mix the first tank pretty rich? I remember when I bought my YZ this year, they put break-in gas that had more oil. I was curious if its REALLY that big of deal on a new engine.

[@dirtniron]

No, mix it same as always. 32:1

[@Jordan348_MX]

Thanks! I've noticed that when I turn the gas off and let the fuel run out of the carb, just before it turns off, it revs really high and the RPM's shoot up before shutting off, my YZ250 does not do this. It's brand new and starts on the first kick, doesn't drip and pulls like a monster for a little 125. It came with the V-Force 4 system from Yamaha. Any reason to be overly worried about this?@@dirtniron

[@ncopp4358]

@@Jordan348_MX Yeah, try not to do this on a two stroke. Its not great for the piston and bore. Dries the motor up and youll see piston ring and cylinder wear after you warm it up next time you want to start it. The reason why the RPM's Shoot up is because the fuel mixture is becoming leaner and leaner till the carb runs out. Lean conditions burn a lot hotter and faster, so the rpms will climb. If your bike is idling high and you cant really hear the individual piston strokes when idling, you gotta turn that in and richen it up but onyl after fully warming it up. Also if you want to drain the carb, do it manually. Dont let the motor dry up. You shave off possible hours before a rebuild doing that. Not good.

[@straighttimestirrups]

Break-In

[@dirtniron]

I brake in my bikes tho ;)

[@bryanoliver5550]

The rebuilt sounds great after break-in runs , when will the first oil change be done ? I miss being on a good two-stroke bike .

[@dirtniron]

glad you like it, probably couple hours

[@goinhot9133]

Start it and rev immediately after starting it…. No, let it warm first.. then go ride it

[@kautsarchannel9727]

hi rado greetings from indonesia , i'm who you emailed that i've build my own yz250x e start , i'm sory if i'm not repply your email , the bike i've sell it on january , now i have yz125x 2023 and i'm start to build e start for yz125x ..

[@dirtniron]

hey brother, send me the video once you are done ;)

[@kautsarchannel9727]

@@dirtniron sure rado , its better simple than the yz250x estart , i'll make sure to note the part so you can make 1 in your country ! 👍