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

PLEASE, do....

@@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!

​@@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

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

Start building your own engines!

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 .

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.

Get an older model ktm 300 or 250 exc

That’s called a 300exc

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.

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.

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

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

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

Can I ask what you did ?

@@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

What else would you run on a 2stroke?

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

Email Jay with questions! Contact info in About tab.

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

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.

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 .

Email Jay. Contact info in About tab.

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

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

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.

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 .

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.

@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

@@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.

@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.

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

Curious on the numbers for this as well !

@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

Most likely around the same price

@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

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.

@@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

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.

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.

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

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.

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

Since about 1978.

It has a carb so no lmao

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

P

@@jpesicka999 amatuer 🤣

Max a tuner have get is 4 to 5

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

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.

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 ! 😅

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

Basically, probably good for 49hp tho.

@@derek3107 yeah probably

@@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.

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.

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.

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

@@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.

@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.

@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

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.

Combustion efficiency

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

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