Two-stroke tech: Set-up secrets of a Yamaha YZ125

Take a stock 2020 YZ125 and make it even better. That's the mission of MotoHead's Dave Willet, a former British 125 champion with more experience of the YZ125 than just about anyone else on the planet.
From jetting to squish, pipes to clutches and more, he talks through the initial set-up of the smokin' YZ!
It's like one man's personal love letter to his favourite bike!

[@joeshawley1626]

Loved the 125 when i was much younger! Been through all different bike sizes and brands, and now at 50 im back on a yz125x and a kid again!

[@borntwice4724]

Joe Shawley right there with you.

[@MS215_]

Man i also want a 125 but im way too heavy at 220 pounds

[@borntwice4724]

Syx215 eat a few salads and get a 450, I’m 190 and it’s perfect.

[@MS215_]

@@borntwice4724 im not fat im just tall as hell

[@justincoats7236]

Joe you're the man. I'm 47, I want one.

[@MotoBroo]

just got a 2 stoke yz 125! Loving it so far!

[@husy6806]

Take her to the track man

[@ChristianLance.]

@Syver Bertilrud Your just gonna continue to hate, can't believe you were joking about my grandmas death! 😭

[@ChristianLance.]

Awesome broo, im buying one soon, can't wait!

[@hkkhan8319]

@Syver Bertilrud I like how ur probably the worst rider here🤣

[@thebeast3822]

My guy its a DIRT bike its not a dual sport or a street bike

[@robertnevinson7109]

Binned my 450 and bought one of these, age 49 best move I’ve ever done in Mx. Flying now ✊🏻✊🏻✊🏻✊🏻✊🏻✊🏻✊🏻

[@motomash6143]

I agree mate. I binned my cr250 last year and got a cr125 and I go much better on it 👍

[@motox2051]

Best mx bike ever. It's the legend from the first days of MX what else do you expect? It's Yamaha the greatest company on the planet!

[@djdanfetish1]

I'm 44 if not rode since I was 20 . This yr I bought a 06kx250 I love the thing . Just rebuilt it over this covid bollox . I'm not fast but I'm not arsed it's all about how much fun your having .

[@georgecarmel6114]

Spot on!!! Riding 125's bring back the perfection in a rider. You can see who is better when on 125's. It's what I called the "Momentum Theory" keep it in motion, especially in sand. Plus tweaking the bike is fun. Blew up my 350 sxf and got a 150 sx. Done with 4 strokes.

[@monkeymangonewild]

I’m 6’4” 235lbs and I ride a 125 better than any other bike in the woods. Just ride the pipe the whole time

[@unadillamoto]

Am a 53 year old Kid and Love 125s.Nice zone to Ride. ✌🏻

[@Scottstunts]

125’s make great riders. It makes you focus on momentum and technique. I’ve ridden dirt bikes in Southern California for 20 year and nothing makes me smile more than a 125.

[@kdcustoms1272]

I wanted a 125 as my first bike but a guy called with a clean 04 250 for $1200... No way I could turn it down...love it.. Had it about 6 years now.

[@goldmx1229]

Im 48 My main bike is a YZ 125 2019 I always bring a 2nd or 3rd to home in Open class, Guy take 1st is on a Ktm 150 and obviously more skilled rider than me, My days were from 1988 to 2000 i did a come back in 2012 and tried 4 strokes but prefer 2 strokes for ever.

[@seanhaberman4619]

I just got an 06 and it's so much fun. Ive been on the 450 for years and went straight to the 250f as a kid so I never really rode 125s but this thing is a blast.

[@premix3663]

ive been riding 450s and 250 2 strokes for awhile now but plan on getting a 125 again for the track when prices drop alot after covid, such a different style riding than kids raised on 4 strokes, 125s really teachyou how to ride the clutch and maintain speed through corners and charge alot harder, so much fun, plus the sound and smell!!!

[@peterclark176]

Rode 125s as a youngster, got my son an 08 yz 125 and have a play on it , man this thing is like an instrument, so precise. I check in at 60 years old.

[@andreasstefanou5898]

YZ125 Legend The definition of fun bike

[@ianthompson9653]

Yz125 is the best bike ever made for sure!

[@Dollartwentyfive]

Absolutely love this video man. You put it all into words so well, I recently picked a 2001 yz125 after a 10 year break from a very short lived riding career. Swamped the bike and seized the big sized con rod bearing I’m assuming from superheating the water that was in the crankcase to steam as ambient temperatures were 30+ c. Bein that I’ve always loved wrenchin i figured it could be enjoyable but, what I didn’t expect was just how much fun it would ve thoroughly believe the YZ125 is the greatest bike ever. Hats off for the info (Ps I just replaced all the suspension and linkage bearings that were seized completely solid and might have been lucky to see grease twice… ! Talk about satisfying.)

[@giovannitaraocioguzzi4193]

Thank you my friend, awesome vids, have a 2013 Yz 125, and a 08 Yz 250, love the 125 ! 2 strokes rule !

[@Lee-mx5li]

Great video.. He listed so many of the quality and fun points of having a Yamaha 125, he's absolutely correct.. Thank you!! Enjoy and remember, "Let it sing, WFO!!"

[@motoxmainia]

really enjoy daves insight and knowledge he defo knows his sh@t.

[@683carl]

I have a 2001 yz125... I absolutely love it really fun bike.

[@johnthomas6614]

Good info great Vid. Yamaha should be happy😊 wth the Vid & the Appritation u gave thm 2 day & ovr the years. The YZ has Stood the Test of Time. Wick On ✊

[@Carbon_restoration_mx]

👏🏽 spot on, well said dave!

[@40mmmikemike]

I looooove tinkerin in the gairedge with the cAbarEor

[@Indistinct0]

after watching this video, went out and picked up a used 2017 yz125, and helped me setup my 2007 rm125 also!

[@johnparker9547]

I am the same as many other riders. I was on 450's and 250 four strokes for years then tried a friends YZ125, the next week I went out and bought a brand new one, in one seas so I put over 70+ hours on it, amazing bike. It is hands down the most fun and best handling bike I have ever ridden. Thumbs up Yamaha!

[@get_nicerides8446]

I'm going to start calling it a 1-2-5 now.

[@fullnoyz7670]

How else do you say it? 🤔

[@get_nicerides8446]

@@fullnoyz7670 one twenty-five in the states

[@MrTeeskee10]

Vidoe made me pull my 2003 out of boxes in the garage and put it back together..runs like a champ still..all stock except for a 296 spark arrester..new exhaust, reeds,and fresh top end is coming very soon..

[@TEKKYTWO]

I love the yz 125 ❤️idk what it is but it's just perfect

[@pags1981]

No other bike teaches corner speed like a 125. Plus they sound good and are amazingly flickable 👍😜

[@MotoHead]

True that!

[@rickstorms]

I love these bikes!

[@caspfoniaf1734]

Bad ass love the YZ 125 🤘🤤🍻

[@brianmorrison9066]

Jetting and the head is where the power is.

[@mancavemotorsports]

Ive never benn happier on any other machine besides the banshee

[@Bruce.Wallace]

Love my 125

[@neilthomas7130]

Great video dave keep um coming mate great watch. How much oil per litre do you run. I use castrol power 1 racing and good quality super unleaded. Any feed back be much appreciated.

[@solorunner1389]

You made me smile because I got rid of my Yamaha 250f and purchased a 2020 Yamaha 125. My kids are also on 65/85 and I am actually loving riding the 125 again(its been since about 15 years since i rode one). What changes did you make regarding stock suspension and what is your height/weight? I am a novice rider 5'8 155lb and typically ride hard pack any suggestions?

[@Dukesy]

awesome vid

[@sian880]

Dave i love the vids iv just got a yz 125 and doing the mods you have,what jet would be best on the TORQUE pipe,not after every last hp just want to keep as you said my head out the carb on the safe side

[@jeanmichelsaintpierre6869]

Hey mate, great Video. You r making my decision between choosing a KTM and YZ125 really hard now. I am unable to get to any demo day in order to test ride them both so I will buy one without even trying it. In Australia, the yz125 s now fitted with a free race kit consisting of a Launch master system, GYTR by HGS muffler, GYTR by HGS exhaust, V-Force 3 reed block and a blue 48T GYTR alloy sprocket. Do you know how these improve on the stock yz by any chance.

[@wakeuk8180]

Great watch

[@Indistinct0]

now that i've had the yz125 a few days getting everything set up in the shop, i noticed the fork guards are rubbing the anodizing on the fork tubes around the wear ring pretty bad, i was thinking to use the skf mud scrapers ms48km i think they are, wondering if you had any light to shine on this topic - thanks!

[@youngyarnzy777]

2 strokes all the way!! \m/

[@paultselembis4255]

Almost all exact my thoughts and situation..I bought 2

[@timsantos906]

Love the Video! Title claims secret set-up Tipps and then there is this guys just telling 12 minutes straight why the yz is an awesome bike and that you should basically just change the pipe 😂😂 And I have the same opinion to be honest 😁

[@kieranpalmer9438]

Wish there was tracks that looked like that near me

[@davidpettersson2260]

Just bought a yz125 2015 as my first bike

[@mattjames6078]

Nice video mate , anyone no where this track is ? It looks mint 🤙

[@jimpanzer07]

Love seeing fast guys on 125 smoke bigger bikes!

[@jgs1703]

The yz125 is an all out race bike.

[@mattcowlard4662]

You mentioned you run the dep rev pipe i thought you favoured the torque pipe with shorty silencer?

[@jedimastergrogu3140]

I was thinking of getting a 250 but looking for a 125 just in case any of my buddy’s want to ride or learn when we head out to the hills.

[@OscarH-oq4xw]

Do you think one of these would be good on the road because I’m thinking of getting one and making it road legal when I’m 17

[@angelosantaniello4113]

I love my Yzed one two five

[@coopronacher372]

😭

[@ianmangham4570]

They go like the clappers

[@broncobill861]

Do love a yz

[@mikebrown41182]

Great! But i was suprised he did not say anything in regards of the Reed intake. Vforce, boyesen? As i believe is a easy improvement for any two stroke. But yeah i love it. The Yamaha 2 stroke 125 is a piece of the forgotten era. More two strokes to the people! 👍🏼

[@Bruce.Wallace]

He mentioned that he runs the Rinaldi kit, which comes with the VForce.

[@mikebrown41182]

@@Bruce.Wallace Not sure if Rinaldi kit does, but GYTR should come with Vforce.

[@mandingo9594]

I mainly ride trails went from a kxf450 to yz250 first 2 banger ive ever owned best decision i ever made

[@shannonscott5788]

I too ride a 2015 kx450 mostly set up for trails an I do like the torque but bike is heavy an wares me down at 45 years old. Do you think I should buy a 125 2t or 250 2t? Will I benefit? I’m 215lb.

[@issac951]

my dad bought me a 125 I'm 15 and he kind of doesn't know a lot about bikes and I don't really either but i want to race in this video I'm really confusing i don't know nothing about 450 jetting and all this other stuff can someone explain it to me?

[@BigDsRc517]

Bike sounds so damn good and looks fucking awsome, might have to replace my kx100

[@LSXTyler]

A lot bigger bike compared to a kx100

[@robertnevinson7109]

What petrol/oil ratio you using?

[@jacobmccaffrey5848]

What track is this please?

[@benfairhall5331]

Is that 2021 Alpinestars gear?

[@michaelrivera6788]

Great video! What’s your weight? I got the same bike but 2021, I am 170 pounds and was wondering if I really need to change the springs on it!

[@zeekdavis11]

No. You’re pretty on par, borderline perfect for factory spring rates

[@zeekdavis11]

Incase you’re wondering factory rates are .42kg/mm forks, 4.7kg/mm rear spring. Recommended for your weight is .42-.46kg/mm front fork and 4.7-5.0kg/mm rear spring

[@michaelrivera6788]

Thanks for the info brother🙏🏻💪🏻

[@choi6326]

How much is it?

[@mikekraz6193]

nice!!

[@hardendurobosnia17]

2:24 please, are you giving it full gas here or? I have a ktm 300 do i just give it full gas or feed it in? 🤔

[@hardendurobosnia17]

3:12 what abou this one?

[@gergokarosi4088]

Hello, Im sorry for this question If you don't want to answer it you don't have to, how much do you weigh? Cuz I have a Yz 125 Im 186cm high and I weigh 187 pounds, do you think this bike can hold up, and do you think that under this amount of weigh is it strong enough? Or should I get a 250?

[@rapscallion3421]

250 125s are setup for about 140-150lbs rider

[@Sam-bz4hf]

Brilliant video from sam oates bideford and demi the dog

[@niklassvensson9119]

You run a 45 pilot or 40?

[@HobbitHomes263]

The fun part of a 125 is that it sounds like you are going like mad even you you aren't

[@ADR-jn2vi]

Mantap 👍

[@franciscolopez3229]

You're right, it's not a kids bike and I agree a 100%. Why? Because, to those who are saying that a 125cc is a kids bike is for me a HUGE INSULT to all the great riders of yesteryears. One big example is, Johnny O' Mara at MXDN in 1986. He on a 125 and beating Dave Thorpe who was on a 500cc. Now tell me you guys that a 125 is a kids bike, are you telling me that Johnny "O" is a kid back then? I don't think so. And take note, that same thing happened again in 1996 in the Spain MXDN with Steve Lamson on a 125 "if I'm not mistaken" beating another British rider on a 500.

[@jonathangofast559]

To add to your last comment, they sound great too.

[@therealundledane1926]

y zed 1 - 2 - 5?

[@thelastrebelshow1627]

2 strokes best and well, you know the rest. 🤟

[@Luca115xZii_LucasAdventures]

What is squish

[@interstellaraxeman4468]

Yes,.......

[@joserizal877]

What's your height and weight, tia!

[@DisruptiveUnicorn98k]

my first decent bike was a yz450f before that it was a ktm 200 two stroke and i think i felt safer riding a 450 than the ktm 200 also my firt bike i ridden on mx track was the yz450 but its true you can get hurt real easy

[@michaelstack5328]

I'm 63 and just bought one

[@bermbuster6]

Would be nice to know who the hell’s talking? He’s clearly somebody that knows what he’s talking about and I really like him. I just have no clue who he is.

[@mikefroneberger6266]

Yamaha is the only way to fly..

[@borntwice4724]

Blu Cru for life.

[@federicotorres9728]

Justo en la pobresa lpm

[@nicholasmorris617]

You should put a stic metering block in it. It will blow your mind. Totally transforms it into a mini monster. Check it out at Sticsupertorque.com

[@justincoats7236]

I've never heard of that. I checked out the site. Interesting. I love looking at products to help with power. Do you have this on your bike or do you work for the company? What does it do?

[@nicholasmorris617]

@@justincoats7236 I had it on my old bike that I sold. It was a 125. It makes it feel like you bolt a supercharger on your bike. It mixes the air from the pilot into the main. A bunch of science stuff but basically makes the fuel more of a vapor. So smaller molecules means more air around the fuel and more fuel. So more power. And it adjust (somewhat, like a lectron) for altitude and temp. Have to adjust for extreme changes but you got to try it. Its awesome

[@sandmanbub]

.@Whoop!

[@messiona]

125 can go just as fast as anything. Look at James Stewart

[@jordantran1434]

The 125 is so good for starters or even if you have experience! It has enough power and it doesn’t have the weight of a 250, so it’s very playful

[@marcialquinones5683]

true for me I keep yz 250

[@devyn4595]

One two five

[@HobbitHomes263]

You get th epipe, reeds and squish right..you don;t have ot touch the jets much if ever.. WHy factories send out bikes KNOWING all of that is beyond me..or maybe because they make more money selling part sthan bikes. The Gilette model. Razors are free. Blades are $10

[@Akokorudagmailcom]

I have no idea what this guy is talking about with “squish” and some of his other terms

[@anthonydalessandro6587]

480-500 main jet? Don't touch the pilot? Sounds very uncategoristic of a YZ125 at sea level running on C12 race fuel. Cant imagine one of these bikes running with a 500 main jet, I would picture the silencer on that bike spitting black oil everywhere, and falling on its face in sandy turns.

[@muscle-milk-ktm1346]

You do if you’ve got it pinned everywhere, I ran a 500 main at Lommel, ran perfect.

[@Nvenus27]

Oh my gosh… Stop calling it a 1-2-5!! One Twenty Five It not complicated.

[@MS215_]

Anyone riding it at 200 pounds and more?