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

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

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

Great video, Tom Morgan does VERY nice work.

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

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.

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

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.

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.

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 😃

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

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!!!!

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.

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

Can’t wait to see the track review

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

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

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

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

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

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

Are any gearbox replacement for more top speed

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

Awesome

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

Good clutch that may be bias 😁

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.

Top harware.

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

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.

air filter?

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

What about a STIC mod for the carb?

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

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

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

Need to dyno tune lets see some numbers .

Why no upgraded carb?

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

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

My local dealer sucks 😢

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

Oooh v force reeds im out lol

CARB + JETTING???

👍👍👍👌👏👏

That's alot of HP for 2 wheels

1K👍

10 hp not happening.

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

Hey Bubba, here in California its illegal to not have the full four bolts on youre vise. Im going to have to report this unfortunately.

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

just get 300cc 2t ;)

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.

10 horse 🐎 powers😂