Ryan Villopoto Yamaha YZ125 Two Stroke Replica - Motocross Action Magazine

#twostroke #racing #motocross #2stroke
After building so many two-stroke project bikes in a such a short time, we have burned out on our garage-queen fixation. Exotic parts and fancy anodized doodads and bolt-ons have lost some of their appeal. For this month’s 2020 Yamaha YZ125, we wanted a no-frills race bike. We only wanted to change the stuff that needed changing, work on the items that needed help and replace the parts that we knew could be better. Don’t get us wrong, we didn’t want an ugly bike; we wanted the most functional 2020 Yamaha YZ125 possible. Here is how we achieved it. Choosing the man to build our YZ125 engine was a no-brainer. He is the greatest tuner in the history of motocross. His engines have won over 200 AMA Pro races and 20 AMA Championships. Going to Mitch Payton is like going to the top of the mount for heavenly guidance. We handed him our engine and never looked back; we knew it would be right.Mitch milled the bottom of the YZ125 cylinder to lower the port timing, then he raised the ports back up with artistic curves, matched the power valve, staged the transfers and machined the cylinder head to make room for the piston to complete its stroke inside the head. Inside the head he reshaped the combustion chamber and squish band. Mitch added a special one-off Pro Circuit piston with a very thin 0.80mm single ring, a heavier flywheel (which most tuners would think was blasphemy) and a special YZ125 black box. A Moto Tassinari V-Force4R reed cage was bolted on, and the tank was filled with VP MRX02 with Castrol at 32:1. It is a rocket ship. In stock trim, a 2020 YZ125 makes 33.53 horsepower with 15.55 foot-pounds of torque. The Mitch Payton-engine pumped out 38.32 horsepower and 17.64 foot-pounds of torque. We’ll do the math for you. Our race engine was 4.8 horsepower up on the stocker and 2.1 foot-pounds of torque stronger.The MXA test riders liked everything about the Pro Circuit YZ125 engine. It was stronger than the stocker at every point on the curve, pulled harder through the middle, and was planted to the ground, which we attributed to the heavier flywheel. Once the engine got to the working part of the rpm range, which on a 125 two-stroke is above 9500 rpm, it really came to life. It was not just fast; it had a broad pull through the midrange. It wasn’t a peaky, wide-open, all-or-nothing powerband; it was the strongest YZ125 engine we had ever ridden. Best of all, the YZ125 was no longer playing second fiddle to the KTM 125SX. The MXA wrecking crew can boil the most important thing that we did to our YZ125 down to sending the engine to Mitch Payton. The most important thing about a 125 is how fast it is. Mitch gave our 2020 Yamaha YZ125 two-stroke almost 5 horsepower more than the stocker.If you have limited money to spend on a hopped-up YZ125, spend every penny on the hop-up. You don’t need fancy wheels, exotic works forks or custom graphics. If it were us, we’d race a well-prepped beater with the Pro Circuit YZ125 engine in it over the prettiest garage queen on the planet with someone else’s engine in it. It’s that simple.
Full Build Details- motocrossactionmag.com/mxas-r...
Subscribe to Motocross Action:
hi-torque.com/product/subscri...
Follow Motocross Action:
/ @motocrossaction
Motocross Action Website:
www.motocrossactionmag.com/
Motocross Action Facebook:
pages/Motocr...
Motocross Action Twitter:
/ mxaction
Motocross Action Instagram:
/ motocrossactionmag

[@Coopdegras]

Being A mechanic and riding for 25 years I've rode a lot of bikes but for sheer fun factor there's nothing better than a yz125

[@caydenthompson126]

I sold my KTM 350 for a YZ 250 and not regretting a thing!

[@walkeryost7135]

This is a interesting point of view. I can't decide between the two. Also looking at a 125. I'm on a 450 now

[@caydenthompson126]

@@walkeryost7135 If you race for a living a 4 stroke, anything else 2 stroke.

[@petardimitrov5976]

This bike is awesome!

[@mattbraap519]

work of art

[@cheeseeater1349]

All around Nice bike hands-down keep the good builds coming 💯💯💪🏿💪🏿

[@Mxbuzz]

YZ125 is the best !

[@joenobody2580]

Mitch Payton 👍👏💪🤙🥇

[@johnthomas6614]

I've wrked at Yam Shop since 95. & whn Mitch does it U no its goin 2 be Insanely Fast & whn MXA puts there twist on it. Its goin 2 be Freaking AWESOME‼ I wood love 2 Ride tht M-F - ER ✌

[@vwsandvettes3253]

Do you guys have a parts price breakdown? I'm especially interested to know how much the WP suspension front and rear would set a Joe Schmoe like me back. thanks for the video. Edit: later in the video it mentioned the WP forks run 4 grand!!! yikes

[@333studios.]

i love the bike

[@faisalallham353]

Elegant bike

[@jpesicka999]

Idk if I've ever seen a bike where they replaced KYB SSS suspension for WP cone valves. That's definitely a first for me.

[@pinnedoutmx]

Same thought over here. I don't get it, KYB SSS are the best for that bike

[@andreasstefanou5898]

Thibault Benistand won the emx250 championship with KYB A-kit(not the factory kashima coating) suspension, wich is pretty similar to the stock KYB SSS. i think a good revalve and respring will be more than enough for 99% of the riders out there. Wp cone valves are awesome but in my eyes is a waste of money. Beside that, what an awesome bike. Makes me also wanna send my engine to uncle Mitch...😇

[@andreasstefanou5898]

kzbin.info/www/bejne/gYurlJ6GiJubfZI

[@reeveharper8424]

KYB A-Kit is much better than SSS. KYB SSS is by far the best suspension to ever come stock on a bike, but pro suspension (such as WP Cone valves or KYB A-Kit) is much better than SSS

[@andreasstefanou5898]

@@reeveharper8424KYB A-kit is not the equivalent of the WP cone valve. The KYB Factory is. KYB A-KIT is between KYB Factory and KYB SSS. Basically is the KYB SSS with better internal components but they way they function is pretty similar.

[@reeveharper8424]

@@andreasstefanou5898 you've clearly never done your research. KYB A-Kit and WP Cone valves are both available at a consumer level, and are both comparable. That's why you'll find so tests and articles putting the two head to head (as well as the Showa A-Kit). What you can't get is the Pro rider's suspension. But Cone Valves and A-Kit are as comparable as you get, they even cost the same amount to buy

[@reeveharper8424]

@@andreasstefanou5898 Also there is much more to KYB A-Kit than just being an upgraded SSS fork. Go do your research

[@Fassfilmz]

One of the coolest sounding bikes but I did like the pro circuit suspension but the wp is a nice touch

[@matthewchevres4970]

So with the Hinson setup, did you not use the Hinson clutch fibers/metal plates and use OEM fibers & plates? Just wondering cause you didn't mention the Hinson fibers & plates. Thanks

[@deddyseptyo9729]

👍👍👍👍

[@davidramsay1055]

Would be awesome to see a stock YZ 125 vs a built one

[@terhune9912]

That a boy Josh

[@AngelGarcia_420]

Nice bike.. $$$$ . I bought and rebuilt my 02 125 for $1500. .

[@ethanreynolds6477]

Anything mxa does is going to be sick

[@offroad_bros_2705]

topp

[@kevinparent8843]

can we get a nice rocketship for amateur without using Race gas in a yz ? Like porting, working the base, play with head or shims . i want some tips. i Dont want to run race gas in mine because it's for fun, but i want more HP'S. MAYBE run avgas can be an option if i can't get something good without increasing the octane

[@ryanbarker4422]

I would still want pro Circuit KYB shock's.

[@64maxpower]

Whatever size RV used on the rear sprocket MXA went one tooth higher on the rear sprocket

[@bmxguy73]

and a stock 125 sx is 38 horse haha, still way sick bike!

[@alexzanderarmstrong]

Wouldn’t engine work change choice of pipe? Like stock bike might like one better?🤷‍♂️

[@333studios.]

You'll have to use factory bikes as a example of what goes good with what bike. I'm building/built a StarRacing yz125 based on the parts they used on there team. You can get specs for each part and kind see what it's doing but really all you need is a FMF or Pro - circuit with the right jetting. If you are racing Id going with a more in depth approach with what parts and your bike/ability.

[@trx250rpuma4]

First here peeps 🏁🏁🏁

[@Mxrider92i]

So in your opinion, if you're going to mod the engine and change the suspensions anyways, what's the interest of picking the yz over the ktm/husky ? ( I'm talking about buying a brand new bike, not picking an '06 yz for cheap :p ) PS : it's a legit question , I'm not trying to argue about your choice or anything

[@imtheplayerandthecoach2409]

There cheaper too buy an parts cost less compared to KTM/Huskys

[@caydenthompson126]

YZs hold their value well. Everyone wants to buy them used.

[@kraighawkins2919]

I could watch this all day. Still baffled by the heavy flywheel. Trying to figure out why Mitch would put that on it.

[@twistymcslide2]

dont think of a flywheel as its own component, and think of it as part of the entire rotating assembly. with their use of an aftermarket piston , flywheel , clutch , and modified crank ( or custom ) , you can lose/gain weight in one area , but still as a whole weigh less , and or just work nicer together. too light a flywheel allows the motor to spin faster. and too fast , is too fast. so id think they use it to counter some of the other weight losses which helps maximize torque , and doesn't limit peak HP , where the engine is working the most, and the majority of the time . . they arent worried so much with the low rpm loss. id not be surprised if that also is the reason for the 4 tooth increased rear sprocket . though i'm surprised they didn't go to a 14t front and a +/- 1 toth rear . but i'm sure they have their reasoning . . ive found the 14t front ( 13t factory ) and a 48t rear ( 49t factory )to be the best combo so far on the 2022 model .

[@bmxguy73]

the meat and potatos of this bad boy *slaps seat*

[@joenobody2580]

Put the moto jedi they call Danger Boy on this bike

[@SSpecialDelivery]

Sounds like she needs packing. Sick bike bro

[@francocastaldo1473]

WP con molle in titanio

[@pakoymotovlogs9382]

2 STROKE COLOGNE FOR REAL MEN :)

[@dicktrickler]

You literally downgraded in suspension UNLESS your dude is a ktm guy that is used to wp stuff. SSS is the best fork ever made hands down

[@garrett3234]

Wp cone valves are better tbh. SSS is the best stock suspension ever

[@garrett3234]

@Syver Bertilrud if SSS is so good why do no pros or ams trying to go pro run it? At A1 i saw a vast majority of people on cone Valves or A kit which neither are SSS

[@prajuritsemut3134]

Ini motor favorit ku namun sayang. Ku tak dapat membeli karena harga masih lumayan mahal di indonesia

[@bigwheel555]

bike has a 52 tooth on rear

[@Aint1S]

Ha! To all of those internet experts 🤓 talking trash on running a little heavier flywheel!

[@jdc9128]

I got to admit I was wondering why they put one on a 125... I just put a 9oz on my yz 250 and il be honest it took more snap out of it than I would of liked.

[@caydenthompson126]

@@jdc9128 Do you recommend me swapping the stock flywheel?

[@johnhouston3681]

Its only money.

[@dicktrickler]

Why in the hell do you have WP’s on a Yamaha?

[@mxr7586]

More than likely sponsors.

[@dicktrickler]

@@mxr7586 true. Plus I gotta respect em for doing something just to be different

[@fullnoyz7670]

Wp on a yz is like putting a Ford engine in a chev

[@edenschreiber2910]

wp conevalves is like the best suspension made

[@Tibingi84]

@@edenschreiber2910 after Ohlins...

[@ED-on8to]

@@Tibingi84 😂😂

[@kendallpalladino9982]

@4:03 13/52

[@kadenrwy]

I was just abt to comment this

[@fkhan577]

Why would a guy like RV go UP 2 teeth? on a 125??

[@kendallpalladino9982]

@@fkhan577 idk man. Just saw the rear sprocket said 52 and he said 13/51

[@toddh137]

since when did RV run WP and Bridgestones LOL

[@caydenthompson126]

Never lol

[@marissaludwig486]

Motorrad fahren im thailändischen Dschungel! Mal was ganz anderes,; kzbin.info/www/bejne/g5C7YXSJfLamotU

[@r_mgn6247]

WP 🤷🤦