Get more POWER out of a 2-stroke dirt bike! YZ125 build

[@64maxpower]

Tom is the only person I'd trust to work on my engines. His knowledge is only 50% of the package. He is kind,shows patients for stupid questions, meets every deadline,even early and not nit picky. He had to add parts to my job. He didn't charge me and wouldn't take payment for the extra He put into it. I'd invite Tom to Thanksgiving Dinner. I feel the 134 is perfect. I had a 144 and wished I never modified it.

[@dirtniron]

thanks for sharing, Tom is the best!

[@robyohr2619]

I have been waiting for this video! Building one of these myself, Keep up the good work!

[@Kawiboy]

I got the 144 and absolutely love my bike.. I run a PC pipe and shorty silencer. She's just a BLAST to race and ride 👊.. Enjoy your bike 👍😉.. OLD G 😃

[@dirtniron]

thanks brother! how does it feel compare to stock 125?

[@Kawiboy]

@@dirtniron I think it just had a better spread of power from 3rd on. Pretty easy to keep on the pipe which helps this Old Guy keep that smile all day long.. Been one of the best bikes I've owned. 👍

[@basedlord88]

Have much extra vibration? Does it still feel like a 125? I’m sending my engine off to get a complete package but not sure if I wanna do 134 or 144, worry that 144 is going to change the bikes profile too much and I want the bike to still ride like a 125, just one that’s really fast

[@mikebrown41182]

Would love to see dynosharts aswell. Tom Morgan has a good reputation, he is a former factory tuner aswell so he got some good stuff up his sleeve. But i was suprised that you did stick with the stock ignition, easy way to get more rpm and longer pulls out of the engine.

[@scummybraap518]

Get?vortex?hpi ?

[@ljm8673]

You should do a pipe shootout for the yz125. I couldn't help but think you should have gone old school with a Bill's pipe setup for a bike like that. I think they're still around in a limited capacity. Bill was one of the kings back in the day. Especially after yamaha was doing a blind pipe test and Damon Bradshaw chose the Bill's pipe as his favorite. Early 90's time frame.

[@twistymcslide2]

the Bill's pipe for the 2022 YZ125 is awesome . super impressive performance out of mine . they are in business still , but their site is down , and they only really interact on social media or through email these days . but they are still making pipes.

[@SouthernJeff]

pipe might not seem like a big power difference but it really opens up the bottom end of the power, i find my self not needing to clutch in corners i would ussually have to

[@aletrip642]

But it will lose power at high rpm

[@SouthernJeff]

@@aletrip642 a little bit yeah still worth it in my opinion

[@alanmonarchi1411]

Can't wait to see it ripping Rado! Braaaap! Dont forget to "stay on the pipe" my friend!

[@dirtniron]

thanks Alan, will do my best ;)

[@jasonfalcon4052]

One of the greatest bike mods ever Tom Morgan. I loved there 2000 CR 250 2 stroke.❤️

[@dirtniron]

right on, thanks for sharing!

[@Yqsw750001]

Great video, Tom Morgan does VERY nice work.

[@manko330]

In 1999.Tom Morgan built Me a YZ330 Stroker,Crank Balance,Blue Printed Motor,Mod Piston ,Hinson Clutch,Vortex Ignition,Fmf pipe ,Reeds,Custom kX500 Mod Silencer.Why ? Too race the Lake Whitney Texas Series against the 450cc 4-Stroke Bikes. I won the 250,450 cc class.Place second in the open class.and yes, the yz330 will smoke the 450cc bikes even in the deep loam at lake whitney when they ran the the track up the Mountain. Great Bottom,Crazy Midrange,Good Over rev.I like to short shift my motors,Keeps the vibration down less tiring.That motor has been one of the best i ever had.was it a fun bike to ride? No.Too race yes.The funniest bike is my 2012 yz125.

[@dirtniron]

that sounds great, thanks a lot for sharing!

[@paulmryglod4802]

Bro, there was no 450 mx bike in 99. Yz400f was there racing against 250t bikes. 426 in y2k

[@manko330]

@@paulmryglod4802 Hey Dummy.Learn what a Stroker Motor for a Two Stroke is. Learn before you speak.............

[@johngray722]

I would like to see the dyno numbers as 10 horsepower I doubt it unless it was knackered before I’ve done 144 Fmf pipe v force on a brand new yz 125 you get about 4 horsepower in my opinion dep pipe y1g felt as strong on the track as all the other mods put together and that’s on the standard bike

[@dirtniron]

did you have it ported and cut for race gas?

[@johngray722]

@@dirtniron yes and engine blue printed anybody can say this will do that the proofs on the dyno

[@EarthSurferUSA]

What is "knackered"?

[@EarthSurferUSA]

@@johngray722 Now you are saying something different than the mods you first listed. I can tell you that since there is really no calibration for dyno's (Yes, I own one), they will read differently for actual power output, so don't put a lot of faith in somebody's actual dyno numbers. I don't believe what you say with your second post, because you did not say it in the first post. But if you just forgot, (?), it is very possible who ever did the engine work,--did not do a good job and probably does not match your pipe. Have Tom Morgan do it. I can believe 4hp for your first post though. If the 125 us like the 250's (which I have), it is pretty de-tuned stock also, so I can believe 10hp more here, but that is quite a gain.

[@EarthSurferUSA]

Turns out the headline was like a dyno read out. Now he is saying 7-8hp gain with this set up. :)

[@theblishknovk]

How would you change this set up for the 125x? Keeping trail riding/enduro in mind.

[@topstar3]

Wow I bet this thing will rip! Well done Rado!

[@stephenf5707]

Great video. You will love the rekluse. I have one on all my bikes. First upgrade I buy. I put one on my kxf450 22 and wow, that upgrade alone puts so much lore torque to the rear wheel. People really don't know how much these clutches do. On the 125 it's absolute magic!!!!

[@dirtniron]

Thanks Stephen appreciate it! Do you have the same torque drive clutch? Not an autoclutch, right?

[@stephenf5707]

@@dirtniron yes I only use the manual torque drive clutches. they are excellent. definitely a performance mod and not just a durability mod like a Hinson. I had one in my gytr yz125 and it made the bikes torque feel like a 4 stroke but still had the zip of the 2 stroke.

[@alexcazares952]

@@stephenf5707 it’s $1,000 kit 😩

[@mackeymichael]

@@alexcazares952 US dollars ?That's a lot.

[@chrisvozza6530]

I would really like to see what that 155cc is like also

[@marcmarechal8621]

Can’t wait to see the track review

[@dirtniron]

thanks Marc, hope soon!

[@WestDesertRc]

Where do u find the right piston for big bore engines

[@basedlord88]

In the process of doing something similar to my old 2006 YZ 125, sending engine to EBR in Houston to get a full package, already have V-Force and a pipe, Rekluse not gunna be in the budget tho 😪 worried about special fuel with gas availability and prices into the future, also not sure if I want to bore to a 134 or 144, wanna keep the profile of the 125 but have it be much faster of course

[@dirtniron]

sounds like a sweet engine man!

[@jt-yt9yh]

Chrome plated fmf hold heat 🔥 . You'll will never see a pro racer use chome plated 2 stoke pipes. Great video great information. Thanks

[@waynesmith3712]

News flash….He’s not a pro rider!

[@jt-yt9yh]

@@waynesmith3712 my point is that the fmf pipes never tune correctly for that reason. It's a senseless bolt on.

[@waynesmith3712]

Nothing wrong with your opinion, i personally can’t judge as I haven’t tried, I hear people consider the fmf with a shorty to be the best pipe, will have to suck it and see to know.

[@keithpeterson6108]

​@@jt-yt9yh A hot pipe makes better power.

[@QSpeaks]

Good choice on 134.....let's see her run!!

[@rogermelling8941]

I had RM139 v force ported, hinson full clutch bill pipe dep pipe and pro circuit pipe used race gas got about 6 bhp increase the stock front pipe and bills silencer was the best result it had to be jetted like a mofo literally every time it went out .....thank god for 4 strokes

[@EarthSurferUSA]

The 4-strokes were forced on the industry by a dictatorship called the EPA,--no matter what the cost. And it hurt the sports market share greatly. Since 1973, there has never been fewer bikes sold. What was once free enterprise, is now run by a dictatorship. That is satan's work son.

[@HPRaceDevelopment]

10 hp not happening.

[@dirtniron]

looks like you know something about it. What can be expected compared to worn out engine in your opinion?

[@jewintheoven9442]

Was thinking the same thing. But maybe close to 10.. 7 or 8?

[@HPRaceDevelopment]

@@jewintheoven9442 maybe 3

[@marcspencer800]

@@HPRaceDevelopmentwhat you charge to build a 2024 ktm 65sx if I shipped the engine to you?? Ama legal motor

[@cxbra]

I would say 10hp could be achieved. Why? The use of "race fuel". I would say all the mods (134cc big bore, reeds, FMF Fatty and shorty silencer) on 91 octane would do about 5-6hp easily.. the addition of 110 octane should do 3-4 HP using the more aggressive timing of the port job.

[@chadweisser1636]

Hello, why didnt you post any link to all the info you talked about? Be nice to have link

[@dirtniron]

morganracingengines.com/

[@zardportugal]

Top harware.

[@brandonmitchell8846]

Awesome

[@dougl2677]

Did you have any issues using the Rekluse clutch and sleeves with the Wiseco Basket? The ProX clutch basket has a note included with the basket stating the clearance is tighter than the OEM and that only OEM clutch plates or equivalent should be used.

[@dirtniron]

no, I did not assemble it yet but I am pretty sure the clutch plates size is bit smaller to accommodate those inserts that comes with it. They make it in the way to fit stock basket as well

[@dougl2677]

@@dirtniron Some of the aftermarket baskets have tighter tolerances. ProX has a note on their instructions noting that with their clutch basket for the YZ250 I am just curious if the Wiseco basket is the same. I called Rekluse about what dimension is required and they stated their Torq Drive plate system is set up to work with OEM basket tolerances with the Torq Drive clutch plates and steel basket sleeves

[@Tizzy_p]

Hey my rm85 02 has the crank cases ported as such why would this be?? We was talking about the airscrew th other day if you remember lol

[@EarthSurferUSA]

Crank cases can be modified, but not ported. Like the "port holes" on the side of a ship, the porting is in the cylinder that defines the port shapes at the cylinder wall.

[@flipcastadventures8541]

how much would that set you back, getting the jug & head done? I'd like to send mine in to get the professional build quality, but wouldn't be afraid to build my own if that service is costing too much.

[@dirtniron]

it depends if you need to have it replated too.. I would get in touch with Tom Morgan and ask him

[@afiqsuhaimi5818]

My motorcycle i moded it from135cc to 250cc.. the block size from 54mm to 65mm.. the crankshaft im using racing.. my rod i uses a longger rod than the original (+8mm).. the engine im using full racing bearing ,, gearbox im using racing gearbox,, oilpump im using racing oilpump ,, the head im using superhead.. original head the valve size is 17mm exhaust and 19mm intake.. superhead valve size is 22 exhaust and 25mm intake..the gps speed for standard 68mph and after i moded all this the speed increase up to 125 mph.. 4stroke not 2..the biggest block size for my bike is 80mm.. onemore things the cam im using racing then the clutch standard is 4 spring i change it to racing which have 6 springs.. and the spring im using racing spring

[@fendymohd3904]

Tiber😂😅😅....org smbang pasai 2 stroke... Tiba2 ckap spec motor ko plak😂😂

[@krisberkowski5973]

Need to dyno tune lets see some numbers .

[@dirtniron]

I would love to tune it on the dyno

[@stuartatkinson3784]

Can’t wait to see the finished bike! I loved racing motocross this year on my 2022 yz 125x even with it totally stock, but I remember you suggesting a JD jetted keihin carb and FMF pipe for my 125x and I am ordering them this month. What carb are you going with on your build? # still motovated

[@dirtniron]

right on Stuart, glad you are having fun on 125x! I will be using stock Mikuni with good jetting from JD

[@joshuarudd7690]

I've got the yz125 with dep full system v force 3 reeds stock jetting bike runs spot on for 125 got really good low down power

[@frankbirger8278]

How can you get more power with a fmf pipe or any pipe they look like stock pipes

[@EarthSurferUSA]

Every section of the pipe from the header section to the stinger can be changed to get a shift in power and power increases. They do look similar, but if you measured each pipe section and tuned length, there are differences.

[@vijaykorvekar1009]

Are any gearbox replacement for more top speed

[@mruble38]

smaller rear sprocket

[@SL4US]

What most dont realize. The stock pipe usually has the best HP results. Yamaha doesn't purposely leave hp on the table, they pour millions into r&d. The only thing they'd potentially short on would be quality of materials. Those fmfs are usually come in last but have decent torque numbers. Kinda pointless for a 125 tho

[@EarthSurferUSA]

As an engine builder myself, (smaller 2-stroke engines/top end kits that I port with a cnc mill, as I port a lot of them.), you do have a pretty valid point. But, everything can be improved. I am sure a good custom pipe builder can find more power than most stock pipes for a particular cylinder/head.

[@talon0863]

Dude, you can make WAY more than 10hp by leaving it stock... rejet the carb for e85, add 30% Nitromethane and Blendzall to taste. Yummy! Very good power but you'll need to spray starting fluid in the air box to get'er lit, and rebuilds are more often. But you know what's even better?: YZ250

[@vtecmossy]

Good clutch that may be bias 😁

[@straighttimestirrups]

And? Did you ever get the engine assembled and tested?

[@dirtniron]

almost there, its a full frame up restoration and I am taking my time.. kzbin.info/www/bejne/pqaVdmyhgKqMsLc

[@yeahdark4282]

air filter?

[@Derekfl19]

Why no upgraded carb?

[@dirtniron]

Stock carb with good jetting should be good

[@chasenorman7827]

Here in South africa I could just about buy a new bike with the price of all those mods

[@tommygerlachjr.1876]

These mods are under $2,000 US Dollars... Maybe if you ride a TTR 50!

[@jrmora6443]

My local dealer sucks 😢

[@joecarlino7870]

CARB + JETTING???

[@dirtniron]

stock carb, jetting specs from Tom Morgan. Will report back after riding

[@ianarenas6469]

🎉🎉🎉🎉🎉🎉

[@danielwhiteley5941]

Not a single mention on carburettor!!!! Same /different, jetting … nothing

[@dirtniron]

stock carb, jetting accordingly.. will see what works the best

[@jakewood4329]

That's alot of HP for 2 wheels

[@rockman49er]

Oooh v force reeds im out lol

[@Briank-ef5iq]

Me personally wouldn’t spend that much sash for few horsepower, that said can’t wait to see the results!

[@dirtniron]

yea, I am super curious too ;)

[@billdeck9766]

@@dirtniron We have done a few of these with honda and yamaha. We used Eric Gore Racing and you can really feel and hear the difference.The bigger bore 144-155, need a little more maintenance than the 134. We did one of those also. TMR has done a few of our Cr250's also.

[@tripleb8819]

👍👍👍👌👏👏

[@the_Novelist]

1K👍

[@hugoseguin8040]

Just buy a bike, leave it stock and ride you'll get alot better spending your money on gas instead of useless part that 99% of the rider out there dont need.

[@jeffpaxton9172]

If you guys want to waste your money, send it to me.

[@denniswilder3014]

Its not a 125 anymore

[@christerandersson5556]

That cylinder wont fit the 2022!! That is a 2021 cylinder!!

[@robsonenduro3316]

just get 300cc 2t ;)

[@dirtniron]

I have one