Jay… you are the man! Tom just did my 1993 CR250 complete engine, just waiting on it to arrive…. I’m betting it’s going to be a ripper!

Nice bike. Tom built me a YZ315 stroker a few years back. We had it at RBSR 2019. Thing is fast and most importantly, smoother then stock 250!

That's just awesome..I once had a 2004 yz 250 2 stroke..rebuild it bottom & top..& man it was a beast fs👍😁🔥

So cool to see how it’s coming along. Excited for the next part

I love your dedication to the tire change!

Man, i love your 2 stroke content! Best regards from germany 🙂

That YZ 250 is real nice sounds awesome

Bike turned out amazing Jay 👍👍

I cant wait to see your comments on the track

Dam sounds soo crisp. Love it

Bring it to Utah!!! The single track is calling you!

Hello, when mounting fmf fatty and shorty on a stock 2023 yz 250, you should change the 178 main jet for one of 180 or 182, thanks in advance, regards

Have you experimented with any of the metering carbs like Lectron, Smart Carb sc2 or XNTG?

I must admit, it sounds absolutely amazing 👏

Sounds so good. I think I’m going to have to run that fmf system on mine 😏👌🏻

@peeonu25

9 ай бұрын

What else would you run on a 2stroke?

Nice Gen-X build, Jay

talking about jetting try the magic Suzuki needle from I think 2006 rm250. I know back in the day they was hard to get cause everybody with ktm was putting them in their carbs.

Balanced cranks are sooo nice to ride your hands dont go numb 🤤

You can also just get a phathead so that way you can swap from the highcomp dome to standard if you need ti run regular gas etc

@EarthSurferUSA

Жыл бұрын

Or keep a stock head also. In think in 2011 or 12 Yamaha lowered the compression, so get the old one for the stock head IMO.

Love the videos. I’ve learned a lot from your instructional information and for the first time ever in a video, think I’ve found exactly what I’ve often wondered. In the road test you turned around and started heading back and stated “Right there.” It sounded like the motor was “sputtering” and I believe that is the rich sputter that would need to be leaned out. Is that correct? Is that what you were commenting about? Again, thanks for the info and love the videos.

@dirtbiketv1

Жыл бұрын

Email Jay with questions! Contact info in About tab.

Nice job. Question - why isn't he taper boring the carb verses straight bore? Also I noticed the head squish area is very large percentage - not revving much higher then stock? I built a high HP 250 2 stroke of another brand, with all the same mods you've shown, plus I taper bore carb (no straight bore). Big difference. Good choice of pipe too with the FMF Fatty. My engine is 15:1 CR with 0.050 squish and I run AV100LL and love that fuel! I've also tried VP C14 (C-12 is not high enough) and there is no difference from the 100LL except the 100LL is more consistent on the dyno then the race fuels. Just thought to share.

6-8! hmm might have to buy and youtube that

@walthendr104

Жыл бұрын

Yes please I’d love to see it on a dyno

@Motoinc

Жыл бұрын

PLEASE, do....

@HPRaceDevelopment

Жыл бұрын

@@Motoinc I think 6-7 with jetting, fuel, pipe, reeds and port and head vs a mediocre/poorly tuned stock bike is reasonable. But just porting and head work worth that much would be amazing!

@Motoinc

Жыл бұрын

​@@HPRaceDevelopment . Yeah it could be with a bad tuned bike BEFORE ...but anyway when making this big of claims it should be woth a Dyno sheet. I follow your channel and hope you test it.....and the beef would give you viewer for sure haha you been here before 😂if the claim wont show on your dyno. Cheers from Sweden

@michaelkritter1694

Жыл бұрын

Thought he did carb, reeds, head for race gas only, port work etc. think the only thing he left off was ecu and matched cases. ​@@HPRaceDevelopment

Like to see dyno chart should be impressive with plus 8 that's around 55 hp not bad.

@EarthSurferUSA

Жыл бұрын

Yamaha claims 45hp stock, and I am sure that is with better jetting then what is sold. There is probably 2 hp to be gained with the jetting alone, and he should be between 51 and 53hp. Damn good.

I had a pretty gnarly high compression build yz125 back in the day when we use to race. Early to late 2000 and I remember having to rebuild it like every 15 hours lol not that it blew up but we were ringing that thing out. My buddy Dayton beavers had a rm125 making lie 41hp it was sick

@kruse1105

Жыл бұрын

Lol ! Your buddies name Dayton Beavers ? Reminds me of my glory days , I can't stop laughing 😂

@COYOTE_N8

Жыл бұрын

@@kruse1105 lol I'm guessing you know the name. But yea he's a friend haha

@Stealth164

Жыл бұрын

Can I ask what you did ?

@COYOTE_N8

Жыл бұрын

@@Stealth164 it was just a really high compression build. Obviously all supporting mods like hinson clutch an stuff. Yours asking about what I did to the bike right. We did a ton I can't remember alot I mean this is 15 years ago lol

Nice sweatshirt man 👍🏼

When are you engine builders going to realize a big bunch of us out here want a 2 stroke that makes a great woods that has smooth power from bottom to top with no big hit anywhere let's face it 90 % of us aren't moto-crossers we're woods an trail riders we want bikes that's controllable an pulls good right off idle an smooth to the top build that 2 stroke seems no one does anymore oh yeah forgot about the European bikes no body can afford

@Cultofpersonality09129

2 ай бұрын

Start building your own engines!

@michaelheiss4456

Ай бұрын

Get a Yamaha WR250 or WR450 that's exactly what they are made for . They make bikes for all types of rides and riding styles . 2-Strokes and 4-Strokes ; I'm betting they are working on a 2-Stroke 300cc bike probably with electric start . I wouldn't put nothing past Yamaha R&D Department .

@mitchalmaines1104

Ай бұрын

Get a YZ250X model that already has slighlty lower compression than a regulay YZ250 then throw a flywheel weight on it and its a woods machine. Handles bogging as good if not better than a 300 ktm/husqy.

@nick2230devs

28 күн бұрын

Get an older model ktm 300 or 250 exc

@zook_291

7 күн бұрын

That’s called a 300exc

Great job

What about if you only would install a that aftermarket pipe? How much hp increase ''alone'' would it do? And maybe some richer tuning on the carb on top of that. Cheers.

8! Over stock that’s crazy fast

I'd like to fuel that with my new STIC Super X2 38/40mm carb. Would be more power than Jared Lesher's SX/National HP tune, bc he only uses the original STIC metering block. My stock 200SX is now mixing it up with faster riders. Pilot jet stawk is a 45, now it's at an 80 with a 200 main combo! The pilot at intermediate idle crosses over to just above the main jet, under hi speed from the vapor filled intake bell...YAT No Choice!

sounds sweet

What’s the $$ on the port job on the head and carb

Awesome, I wish Yamaha would get back into 2 stroke modern engine development. It would be a fantastic motor and bike.

@michaelheiss4456

Ай бұрын

I'll bet they are working on it , in secret . 😊

In the first ride video when midrange was spluttering a tad, what jetting change did you do there, just the air screw or needle clip? Running to rich or to lean? Sweet bike , i have the 22 model, still getting used to jetting changes.

@dirtbiketv1

Жыл бұрын

Email Jay. Contact info in About tab.

Qual a taxa de compressão não corrigida para yz 250 ?

Would be nice to go more in depth with tmr. Biggest performance enhancers would be more peg time, maybe hydraulic clutch or yzx springs to ease the pull in technical shit.

@EarthSurferUSA

Жыл бұрын

I have never had such an easy clutch lever to pull than my stock YZ250 2-stroke. More power will probably mean stiffer springs.

What was pilot jet ? 2nd clip ?

So this more for moto it seems, hows the low end after? Does Tom Morgan do yz250s for woods racing/cross country?

@jimbo4203

Жыл бұрын

I always put on the heaviest flywheel weight I can get , it's great for off-road and still plenty fast if you want to take it on the track

AWESOME

Why not run a Lectron or Smart carb?

You should try the Stic in your pwk

Gotta love the good ol yz,

Cool. I’m partial to ProCircuit exhaust. Better power and sound.

Looks close to Schleisman or pine st

I just picked up a 2024 yz 250 what’s a good website to order pipe silencer and other parts seems like bto and a few other sites don’t have anything for the 2024 in stock

@cadillachernandez2271

3 ай бұрын

You can put a pipe on it as its been the same since 06' i think?? Lol

crispy

I need see a dyno chart before I'll believe it

Maybe it can keep up with the ktm’s now

Is it normal for oil to drip out of the power valve vent line on a 2023 yz 250X

@EarthSurferUSA

Жыл бұрын

Yes, when running rich, as they come stock. I like to drop the needle one notch, but that can be a pretty big jump. In that case, I make a little spacer about half the distance of the drop, and add it to go only half way. Then I tune the main jet, and pilot of needed.

Who does the work and where?

What a nice bike sounds mean

How much did the mods cost?

So is this going to be a trail bike Or motocross? Seems like that build going to be strong off bottom and fall off on top??

@EarthSurferUSA

Жыл бұрын

Nope IMO. It's biggest gains are probably from the mid range to the top end. It is easier to get big gains with higher rpm. Part of the HP equation.

No dyno?

Any idea on price to do something like that for a 2021 yz250 ? Love the show

@azkrie5246

Жыл бұрын

Most likely around the same price

He did say “between” to be fair

Hey you guys could you please tell us a good Main and pilot jet number’s for Southern California ❓🙏🏼❓🙏🏼 I live in Redondo Beach California. PS. I have a stock 2003 RM 250, Pro circuit fatty pipe, VForce 3 reed’s .. I just had a stock rebuild and I can’t figure out the Jetting for shit ‼️😤 please help 🙏🏼🙏🏼🙏🏼

@michaelheiss4456

Ай бұрын

Stock is usually about 2 sizes rich at sea level . Check what the pipe and reed manufacturer recommends . Make a couple of high speed full throttle passes and ; Chop the throttle . Pull in the clutch and come to a stop . Take out the spark plug and see what color it is . Should be a light brown or tan color . Black is too rich and white color too lean . That's sea level . Up in Gorman ; Hungry Valley you will need a jet approximately 2 sizes smaller . 1 clip groove up on the needle jet and adjust the air screw . Altimeter and Air Density meters will be a big help . Friends always wondered how my bikes ran better than theirs . 😊 Write down the Jets you put in and how it affects the way the bike runs . Don't forget to change them back at a lower altitude . Better to err on the rich side than lean . That's why the chop test .

All the money put into that bike anyways why wouldnt put in a smart carb sc2 or a billetron pro 38

The 2-stroke YZ250 may be the tallest bike made, and that is insane. I corner so much easier with my lowered bike and the bars pulled back for riding. Much harder to control the front end with the ape hanger set up.

What would all this cost?

What spring rates are you using front and rear ? Great video

@EarthSurferUSA

Жыл бұрын

Depends on rider weight and skill. If you are over 180 (approx), and using stock springs with the rear sag set,---the front will hang too low, and the handling will be terrible.

@EarthSurferUSA

Жыл бұрын

For suspension work/advise, I think it is hard to beat Race Tech or Enzo. They can both set you up for your riding and weight.

wxyz... nice

8hp h mmm and testing on the tar

I was going to say "No way 8 more HP!!", (would be about 53hp), but this is Tom Morgan, and there is a lot of work done that I am sure matches up (the work done compatible, not mix matched), it is probably right up there with the works Honda's of their 2-stroke hay day.

@michaelheiss4456

Ай бұрын

That's why Dyno tuning is a great help in making sure all the components work together .

2.3 people worked on it lol is a miget the .3?

"I'm the 0.3"

8 over ..wheres the dyno tests😢

Beautiful but it’s a lot easier to buy a 300 which will make the same power for less money and then if want more power you can get a pipe and aftermarket to go hunting 450 ‘s

@michaelheiss4456

Ай бұрын

500's have a hard time with the new 450's ! Most guys can't handle the power of the 450's hanging on for dear life trying to control them . 😊 It like one cylinder off a NASCAR these days . Some are going to the 350's that can make the same horsepower , but easier to handle .

🤙✌

That would put that 250 2 stroke in 450 hp territory. Probably torque as well. As a 450 only lays down around 3 to 5 more ft lb of peak torque than the yz 250. It's just a much flater torque curve... on the pipe the yz 250 peak power isnt durasticaly lower than a 450. have you tried the eddie sanders ceo cylinder and 325 kit? Crank works also offers Atomization Surface Treatment (AST) Roughens the surface of the crank to better atomize the fuel, making for a cleaner and more efficient burn, which leads to more horsepower (2-strokes only).. I would love to see some results from

@denniswilder3014

Жыл бұрын

You can get peak h.p close to a 450.but you can never get it close on peak tourque of a 450.the pipe on a 2 stroke can't do it.

@dormantmenace

Жыл бұрын

@Dennis Wilder bud pull up a dyno chart. It's already there . 2 strokes put down more peak torque than 4 stroke. What your feeling isn't peak torque its torque curve. 4 strokes make torque everywere relatively consistently rather than all at once like a mx ported 2 stroke. That linear power delivery or torque available throughout the rpm range equals traction. Rather than a narrow power window spitting it all out at once. Pnd for pnd.. 2 strokes annihilate 4 strokes on peak tq. Worse than peak hp most the time. But power delivery is what wins races not peak numbers. So given the stock power differences between the 450 and 250 2 stroke. It's not hard to imagine a gain in 8hp isn't going to net improved torque of some value. Not like a 4 stroke were your trading one for the other based on cam profile The 2023 450 motocross bikes were dyno tested at Pro Circuit. KTM 450SX-F: 59.94 hp @ 9360 rpm HUSQVARNA FC450: 59.30 hp @ 9810 rpm YAMAHA YZ450F: 58.95 hp @ 9840 rpm GASGAS MC450F: 57.07 hp @ 9050 rpm KAWASAKI KX450: 56.37 hp @ 9540 rpm HONDA CRF450R: 56.31 hp @ 8960 rpm SUZUKI RM-Z450: 54.87 hp @ 8780 rpm HONDA CRF450R: 37.30 lb-ft @ 6980 rpm YAMAHA YZ450F: 35.37 lb-ft @ 7250 rpm GASGAS MC450F: 36.73 lb-ft @ 7560 rpm KTM 450SX-F: 36.51 lb-ft @ 7190 rpm HUSQVARNA FC450: 36.33 lb-ft @ 7220 rpm KAWASAKI KX450: 35.48 lb-ft @ 6800 rpm SUZUKI RM-Z450: 35.19 lb-ft @ 7670 rpm Yz 250 as consistently rated throughout the web ..The engine produces a peak 48.8 horsepower (36.4 kW) at 8,800 rpm and 30.6 foot-pounds force (41.5 N⋅m) of torque at 7,500 rpm, Although I have seen yz 250 torque listed at 32 to 33 in previous years. But every dyno is different they say.. And I've blown up more 450 4 strokes than any other bike I've ridden. So I understand why you might make that assumption off of the old butt dyno. But it's wrong

@denniswilder3014

Жыл бұрын

@@dormantmenace just did from dirt rider 2022 yz250 37.9 h.p 18.3 ft lb tourque.kaplin cycles dynoed a cr 500 fully built and only produced 57 h.p and 42 ftlb of tourque.

@dormantmenace

Жыл бұрын

@Dennis Wilder that's a yz250f genius. You know the 4 stroke! what are you 17 lmao... oh man.. hey maybe read the article before you go siting it as reference little buddy. And no that's not a fully built cr 500. It layed down more than than stock.. even with the cr 500 having no power valve. I've owned a 89 and 90... cr 500 was also detuned in 86 as the 85 was to powerfull according to the pros racing it.

@dormantmenace

Жыл бұрын

Oh man best part is.. I already gave you all the numbers.. and your out here like your gonna disprove FACT. Cause a 450 feels like it makes way more torque.. it does make way more torque!! All across the rpm range.. just not much more at peak.. despite twice the displacement.. But hey you posting the yz250f dyno chart making 18.3 ftlp vz the yz250 stroke at 30.6 ft lb... just proved what I said. A pnd for pnd... 250 4 stroke vs 250 2 stroke.. of mx pedigree.. 2 stroke layed down almost twice the peak torque... how embarrassing

How would this compare to a 300sx stock?

@Backyard.bandits

Жыл бұрын

Curious on the numbers for this as well !

@ghostrt1608

Жыл бұрын

@Backyard Bandits ... I think it would be real close... Yamaha really needs to just go ahead and offer a 300cc version anyway & maybe do a 300 X model too... I would have bought that instead of the YZ250 2-STROKE that I bought new in 2018

New rider here, how do I mod to have LESS power? 😂

Ktm has already did all that just buy a sx 300 and that will rip !

i just bought this bike and it wont even hold a idle no matter what i do to the air or idle screw nothing changes

@ghostrt1608

Жыл бұрын

@Maximuzz ... u may need to check the throttle cable adjustment.. when I bought my 2018 new from the dealership, my YZ250 2-stroke throttle cable definitely wasn't adjusted right at all... when I would twist the throttle open and let it go, it wouldn't even close and snap back in the closed position and I said something about it to the mechanics in the shop... read the owner's manual for your bike and u might have to re-jet the carb for your altitude and air temperature

@EarthSurferUSA

Жыл бұрын

I had the same issue with my 2019, (same engine). I ended up pretty much cranking the idle screw all the way in, and setting the air screw to spec. I like a slightly high idle so it does not stall as easily when braking for a corner, and it is pretty much where I need it now. It is the least responsive idle screw I have ever used. I think it opens the slid a bit, so I opened the throttle when turning it in.

@oGxMaXiiMuMZz

Жыл бұрын

@@EarthSurferUSA I fixed it I just took the idle screw completely out and put it back and I was able to screw it in more then before

CDI standard?

@EarthSurferUSA

Жыл бұрын

Since about 1978.

The turbine core makes more power

@johnlastname2895

Жыл бұрын

Yea sure that's why all the pro's run a turbine core lol

@MotoFish45

11 ай бұрын

Turbine core adds “back pressure” because of the spark arrestor. Usually makes the bike feel like it has a little more on the bottom end, but in my opinion, then cuts some off the top end. Just my 2 cents.

Factory tuning, factory ecu Map and factory rubber will give you more than 8

@jpesicka999

Жыл бұрын

It has a carb so no lmao

@barkeep25

Жыл бұрын

Factory tuning? You gonna have to crack open Chad Reeds old yz to see any of that.. also the stock cdi (not ecu) is pretty much the best one for the yz. I'm sure spec tires are great, never rode any so idk

@barkeep25

Жыл бұрын

P

@promxrippa

Жыл бұрын

@@jpesicka999 amatuer 🤣

@frankbirger8278

Жыл бұрын

Max a tuner have get is 4 to 5

Would rather just buy a ktm sx which already has the extra 6-8hp stock

@michaelheiss4456

Ай бұрын

Then you have the maintenance issues , KTM'S take more time and money to maintain .

Twin turbo diesel it and call it a day

i think this high compresson stuff destroy the durability and the crank bearings.i use low compression on my 250 best durability lowert temp.

Why not go with a Lectron or Smartcarb? When you want to build the ultimate racing machine you basically have to get one

@jannep6772

Жыл бұрын

Not in my opinion. You can use Keihin PWK Airstryker or even Mikuni TM if you know how to modify them correctly.

Why are you engine braking the bike in break-in so much? At 7:45-> just alot of MMWWWWOOOOOOOOOOO and no pulling the clutch. I wouldnt dare to try that on a fresh piston :D I know its not that excessive but I'd be afraid of doing it.

@EarthSurferUSA

Жыл бұрын

Actually, you don't have to worry about the piston. It is the rings that you seat to the cylinder wall as fast as possible, to reduce blow by and tarnish build up on the cylinder walls.. The combustion pressure actually goes over the ring and behind it and pushes the ring against the cylinder wall for the fastest seating. You can see that when you take off the old ring, it will be dirtier on top than on the bottom. And that means you want to break it in where the torque is highest, (highest cylinder pressure). Some builders when refreshing a engine at the track, would even put the piston and ring in dry (no oil on it), to help seat the rings in faster in practice, and ready to race that day. As long as your jetting and gas mix is good, run it.

Homie can work on bikes but i dont think he really knows how to make a 2stroke sing

@michaelheiss4456

Ай бұрын

You also want reliability . I built one that screamed and would pass everyone but it wouldn't finish a race without something breaking or blowing the head gasket . But it was fun ! 😅

@loadthebowl

Ай бұрын

@michaelheiss4456 dude just can't ride a bike that good get him off the bike... get that man off a the bike

So many claims...no DATA

@derek3107

Жыл бұрын

Basically, probably good for 49hp tho.

@Motoinc

Жыл бұрын

@@derek3107 yeah probably

@EarthSurferUSA

Жыл бұрын

@@Motoinc Don't worry about what Tom Morgan claims. He is one of the best 2-stroke tuners on the planet today. It is also a fairly slow bike stock, (even compared to my 250's from the 80's), so it is easier to get the gains he claims. I would bet it is over 50hp,--at the crank.

Come on guys, the title to this video is "YZ250 Mod with 8 More Horsepower"... and yet not only did you neglect to show the YZ getting DYNO"ed pre and post mods, you avoided even mentioning any numbers. WTF

@EarthSurferUSA

Жыл бұрын

Believe it or not, there is really no calibration for dyno's. Take the same set up to every dyno across the nation, and you will probably see an 8hp difference. Yamaha claims about 45hp stock,--and that is jetted better than what we buy.

@EarthSurferUSA

Жыл бұрын

Tom Morgan is one of the best 2-stroke tuners on the planet, and the stock YZ250 is probably the slowest 250 I ever had, so pretty easy for him to improve really.

Almost performs like a 250f 😆

@chrisvids1820

Жыл бұрын

Way more torque on the 2 stroke, and a couple more hp. I owned a brand new 21yz250f and 96 Kx250 and rode them both for a year. Sold the 250f because it doesn't have enough torque. Is the 250f fast? Yes, for a skinny guy on flat ground on a wide open area. Torque wins everywhere else

@EarthSurferUSA

Жыл бұрын

@@chrisvids1820 I had the KX250 97, and if your engine was like mine, it was a mid range monster. Gave me arm pump bad on the track, (but I was coming back for a few year break and probably no riding very smoothly.), but I totally loved in on 3rd,4th gear sand whooped trails.

@chrisvids1820

Жыл бұрын

@EarthSurferUSA yes! My 96 has alot of mid and bottom end. Sandy whoops are fun on it! I ride it pretty much everywhere from single track to MX, dunes, and desert. I've got the suspension dialed in and it's amazing how good of a bike it is being so old. I used to think that bikes from this era kinda sucked until I learned about suspension. A little history. Jeff Emig won MX on the 1996, and both SX and MX in 1997.

@chrisvids1820

Жыл бұрын

@EarthSurferUSA my next bike is either going to be a yz250 or 2018+ 250sx. I test rode the yz for a short while but never a ktm

4 stroke suck 2 stroke for good time.... comments coming soon when they get off their phones

There's no way you can add 8bhp without a big bore kit

@denniswilder3014

Жыл бұрын

Of course you can.and it's not that hard a good head and fuel package can add 2-3 h.p porting can add another 4-5 h.p tweaking the pipe you can add 2-3 h.p.bigger carb adds a few h.p.all of this can be done and have a reliable bike.now stuff the cases shim the cyl open up the exhaust port timing add a programmable ecu you could realistically add another 15 to 18 h.p to a 250 2 stroke.it all depends how often you want to rering it.i have built some drag sleds and have had some motors built.a stock 800 triple snowmobile with almost the same bore and stroke of a 250 makes 150 h.p.porting pipes bigger carbs and ignition they are adding another 100 to 120 h.p.

@1176hambone

Жыл бұрын

Combustion efficiency

@a_drewski

Жыл бұрын

Look at banshee’s. You can add almost 30 horsepower without increasing displacement.

@skyhawk409

Жыл бұрын

You can add 10+hp to 249cc no need to slow it down with a heavy piston.

Don't you have any dirt to ride on? Stay off the streets.

How much for this package ? @DirtBikeTV ?

Throw it on a dyno