Yamaha YZ250X Ultimate Street Legal Single Track Enduro Dirt Bike Build & Review

[@Gs112780]

Awesome bike!

[@SourceADV]

Thanks! Definitely one of my lifetime favorites!

[@howardwoods342]

Awsome bike. I built my 2021 250X similarly. Though o went with a lectron carb. Also I installed a Apex head with the XC insert. Bike is freaking amazing, fast as hell, single tracks amazing, and I dont care what anyone says, is much better then my friends brand new KTM 300 2 stroke trail bike. Not to mention its more reliable. Yamaha for the win

[@SourceADV]

Heck yeah man! Great bike and nice choices with the lectron and Apex, I’m sure it rips! Have fun out there!!

[@3XTS]

I own two bikes: 2018 Husqvarna TE300 (last carb Husky) and a 2017 YZ250F but you sir have my dream bike. I would switch my YZ250F for the YZ250X ANY DAY and no questions asked.

[@SourceADV]

Thanks man! It was an awesome bike for sure

[@taigops888]

Then do it man, sell the F and buy the x and have your dream bike

[@motosportadv8177]

Well looks like all my 4 stroke friends are going to grill for building bike like yours but for me I miss my old RM 250 2 stroke and you just proved to me that you can have a street legal YZ 250 that can do it all, and it looks like a perfect bike for my region up here in Northern Utah ,You have a super cool bike ! Look forward to more on and off road riding videos in the future! Cheers happy safe riding and thanks for showing us your build series of your bad ass smoker 2 stroker!

[@SourceADV]

Thanks! It’s a great bike, wish it had e start and 6 speed, but it was great!

[@motosportadv8177]

@@SourceADV yeah its nice having that extra gear, iv always wondered if you can maybe crack open the case and use a WR250F 6 speed and replace it? As for E start that after market company that makes one has to prove it self reliable be for I'd buy it ! Cheers happy riding !

[@SourceADV]

I think we'll just have to wait for Yamaha to update the bike... I bet it will happen sometime in the next 2-3 years. Could be cool!

[@elcincero321]

That thing hooked up works better than most enduro bikes out there buddy.

[@SourceADV]

For sure, cheers

[@SourceADV]

That YZ is such a good bike, I wish Yamaha would just give it a 6 speed, e start and 300 CC option.

[@adrenalinaddict8212]

Wow, amazing build! 🤩 Since I'm small and light I bought a small 85SX bw and I'm currently converting it to an enduro bike and I hesitate to buy the SmartCarb due to the price. 2t is new to me so I'd like to learn more on carburetor but I feel I could just skip this struggle with SmartCarb 🤣

[@SourceADV]

It’s pretty sweet, I’m putting another on a hard enduro build right now.

[@mt1885]

I wish Yamaha had a lighting coil stock on the 'X' model. Riding at night sometimes is the most fun.

[@SourceADV]

Agreed! That Baja designs light is sick, but it’s a lot of work to get it working

[@EarthSurferUSA]

You still might have to change the chain length with 13-49, as you are 2 teeth shy of stock. The ration is closer to 3 teeth in the rear than 2.5. I am just going to add 2 teeth in the rear, and keep the 14 tooth sprocket because more teeth is easier on the chain I believe, (one more tooth sharing the load). People who are really picky about their suspension/geometry can get picky about the axle placement. But I don't think that trumps gear choices.

[@grudgetank3127]

im at around 110 hrs on my 20 yz250x, no lack in power fast or slow, , does 130kmh with 13/50 ,lots of single track and forrest service ads, I use 80:1 options 2 ,, I weigh 235lb.. these yz'xs are awesome bikes, mine wighs 234 full of fuel stock tank., cheers.

[@SourceADV]

Heck yeah!! That’s awesome!

[@jonsainsbury8726]

Apex head with SX insert and power valve mod(removing a preload washer)drastically cleans up jetting....using Apex jetting chart...

[@SourceADV]

Yeah but it doesn’t help with how many different elevations I rode with this bike. Regularly 3000-11000 feet Not having to rejet was the major Benefit of the smart carb. Cheers

[@jonsainsbury8726]

Apex head and power valve mod work regardless and will make Smartcarb/ combustion more efficient due to improper large OEM head 100 thousandths inch squish... 5k altitude and above I use 87/88 octane non eth fuel (mixed 32:1) from murphys/Maverick stations ...as 91 not needed at altitude...(most guys mix a lot of 85 In there fuel thinking they are pumping 91...due to not purging the single hose gas pump of 85 into their truck before filling up bike/gas can...

[@SourceADV]

Smart Carb engineers recommended that I do not use a different head on the bike, so I went with their wisdom and the bike ran great at all elevations.

[@jonsainsbury8726]

Weird, because YZ250 has a higher comp and tighter sqwish than the YZ250X... Maybe because smartcarb/lectron tend to run lean either on top or in the bottom depending on tune, and can't really be tuned out...Keihin has a pilot circuit (never change my #45)for tuning bottom while allowing tuning for top end...

[@jonsainsbury8726]

kzbin.info/www/bejne/e3isgnyQoJ2Se8k

[@paulygood6665]

I thinking of racing that bike in the San Felipe 250 in 2022. Great reviews man🏁

[@SourceADV]

Its a great all round bike! I had a tiny tiny bit of fine dust get by the air filter once in super silty conditions like down in Baja. I put on a PC Racing Neoprene dust seal and it fixed it. Take care man!

[@paulygood6665]

@@SourceADV I live near knocksville BLM in Napa county. That’s about 30,000 sq acres of land. I need to ride more of that silt shit .

[@SourceADV]

Heck yeah! It’s fun!!

[@chadrides914]

I had an opposite experience with the Magura clutch in my yz250x. I felt it did not modulate nearly as well as the cable and I did not like the feel nor did I like the bite point. Went back to cable clutch.

[@SourceADV]

I could see that with the stock plates. This bike was switched to an EBC HD clutch with stiffer springs. The bike felt much better with the hydraulic clutch. It was really hard to pull and grabby with the cable. But, every bike is different! Take care!

[@lhurst9550]

Dude, I'm copying your build. Great job!

[@SourceADV]

Thanks man! Definitely a fun bike!

[@craigwilson6108]

Hi. Thanks for these great videos and related product information. I am converting my YZX to street legal dual sport, using many of your suggestions. Did you ever compare the Smart Carb to Lectron? I am trying to validate the cost differential. Thanks!

[@SourceADV]

No problem! Glad it helped. I did not every do a direct comparison, but the smart carb is adjustable externally which really came in handy a bunch

[@chrisschoeny6734]

What graphics kit is on the bike? I love how simple and clean it is.

[@SourceADV]

Thanks Chris!! It’s decalMX T-11 kit with colors I picked to work with the Nardo Gray plastic. www.decalmx.com/designinator/5156?source=button

[@nicolaspugliano3303]

Great video - so much interesting and relevant info in here. Thanks! Also, how would you compare the SmartCarb vs a Lectron?

[@SourceADV]

Thanks man! The Lectron and SmartCarb have lineage to the same origin. Both are metering rod carburetors and do effectively the same thing. For me, the Smart Carb edges out the Lectron because it has a tool-less externally adjustable metering rod (meaning you can make mixture changes with the carb on the bike with it stopped), its fully sealed (it can't leak fuel), the slide design is more advanced for better fuel atomization and can't beat that blinged out looked! If I get another carbed 2T ever, a smart carb will be the first thing I put on it.

[@ValonYaWallin]

Just got a 2022 250x, what premix and ratio do you recommend

[@SourceADV]

For single track riding I had good luck with 40:1 with Maxima K2

[@SourceADV]

Once the bike was properly jetted

[@carlatamanczyk3891]

Klotz Techniplate at 40 to 1. I've used Klotz since 1972 and it's the best 2 stroke oil there is.

[@turcottewill3]

After all the upgrades and what not would you say it's almost comparible to a beta 300rr? Price wise I'd think they would be pretty similar after all said and done

[@SourceADV]

Yeah probably man, I got lucky and bought that bike for $5K with 2 hours on it so that’s why it made sense to build it up.

[@dezracr]

I ride an older yz250x it’s a 1996 WR haha I’ve been looking for a decent headlight so I can street legal it

[@SourceADV]

Nice! Does that one already have a decent Stator or would you have to get a bigger one? The light is pretty darn sweet! Cheers!

[@dezracr]

@@SourceADV it has a factory lighting coil I just need a rectifier . Moose racing has one but I haven’t found one for sale in awhile

[@SourceADV]

Got it, I don’t know much about non battery systems, best of luck!

[@michaelglenn2468]

Why Acerbis over IMS for the tank?

[@SourceADV]

Came with the bike when I bought it :)

[@bartman376]

Nice video! I just got done with building a YZ 250 and was going to sell it but I'm really liking riding it. It's not as good as my KTM 300 but your right its got something about it that's just fun to ride.

[@SourceADV]

It’s true! Just a great bike and you can’t quite put your finger on it, but it just works in so many ways

[@josephfelice601]

Have you experienced any swing arm wear near the counter shaft sprocket with the new gearing? Thanks

[@SourceADV]

The swing arm or the plastic slider?

[@josephfelice601]

@@SourceADV Plastic slider wearing through into the swing arm. Thanks

[@SourceADV]

Got it, I didn’t notice any excess wear

[@dezracr]

Where in AZ is that?

[@SourceADV]

Kelly Canyon trail system in flagstaff and Hayfield in Cottonwood. Cheers!

[@LUCKY.CLIPZ1]

How well can this bike "cruise" at 45-50mph. Want to make a street legal 2 stroke (to get to local trails) but have about a 15 minute ride to them. My KTM 500 is great in that aspect but is not great in the tight stuff. Would love if the X worked out. Any input?

[@SourceADV]

All depends on gearing, mine had +3 teeth in the rear and is pretty wrung out at 65, but fine at 45. Cheers

[@LUCKY.CLIPZ1]

@SourceADV thanks man!

[@SourceADV]

No prob

[@TheKitchenTechnician]

I’m surprised, no Rekluse?

[@SourceADV]

No sir, the rekluse won’t hold the bike on steep hills if the bike stalls, you have to shut it off and adjust manually or you can’t grab some throttle. This bike sees way too much steep technical stuff and I don’t like going backwards downhill and don’t want to add a rear handbrake. Cheers!

[@carlatamanczyk3891]

How much does the FMF pipe help. I've heard both schools of thought. Some say it helps. Some say it doesn't.

[@SourceADV]

Not too sure actually, the bike had it from the day I bought it. All I can say is that the smart carb (once tuned properly) and that pipe work great together. The bike had so much usable low end.

[@JoshThomas-b8d]

I like the Gnarly. It seems to have a better bottom end. The real blessing is that it's STRONG. I smashed two stock pipes. I even put the e-line pipe guard on the second one. That just pushed the whole pipe into the frame. So far the Gnarly barely even has any scratches without a guard. My bike is very similar to this one except for the street legal. The 13t countershaft sprocket is the best mod.👍

[@SourceADV]

@JoshThomas-b8d yeah, definitely thicker steel, good stuff!

[@easternyellowjacket276]

Commenting on the street legalness. Each state has different requirements. Looking at your bike, there is no way you'd pass inspection from the RMV or state inspection requirements in my state, which is Massachusetts.

[@SourceADV]

That’s why I don’t live in New England anymore (from CT) too many rules and no space to ride. I live in AZ now, you can put a plate on a dirtbike that doesn’t even have a horn or brake light… just can’t ride it on the highway. In MA/CT/etc, just buy a KTM 350 EXC-f and call it a day.

[@easternyellowjacket276]

@@SourceADV Yeah, I get that. The problem with CT and MA is they are tiny states with high population levels and lots of rich people, hence the laws. Now, that AZ heat......

[@SourceADV]

For sure man, and no public land in CT anymore. We live in Northern Arizona, not by Phoenix. We live in Verde Valley, where we are it’s year round riding, and the highs in our town is max 98, but dry. You just drive up to flagstaff (40min) if it’s too hot and ride/hike/hang up there.

[@SourceADV]

I'm dead serious about those 350 EXC's though, they are awesome bikes. I have a 350 XCF that is my race bike and it's my favorite bike ever.

[@easternyellowjacket276]

@@SourceADVI heard they were really nice bikes, but somewhat neutered. Is this true? Did you do anything to get more power out of it? Thx!

[@johnmclaughlin4802]

👍

[@MVHS937]

Howdy. Looks like a great balanced build as you said. Seems to have most mods possible. What is the estimate of $$$ needed to go from bone stock to this? 3k, 5k?

[@SourceADV]

Roughly 4K yeah -- so if you can find a used one with low hours for a deal, you can have something that puts you at like 9K for race ready compared to a KTM that would probably be about $13K for the same.

[@MVHS937]

@@SourceADV Thank you. I just bought a brand new one. May have to wait a couple years before starting upgrades lol

[@SourceADV]

Ah got it!! The smart carb is definitely my favorite mod on that bike, but I change elevation a ton.

[@kel4545]

Do you like Tubliss on the front? A lot of people say there is no benefit.

[@SourceADV]

I do like adjusting the tire pressure on the front depending on the terrain. Also, it seems that I always get puncture flats in the front, so it's way easier to fix those with automotive tire plugs versus pulling a tube. I have not had an issue with a plug leaking in the front yet either.

[@willmcgregor7184]

I just got a 2016 Yz250 I’m going to do “enduro conversion mods” What do you think are the 3-5 most important? Thanks

[@SourceADV]

@@willmcgregor7184 I think you will need to regear the chain/sprocket to make first/second gear more usable for enduro riding. Doing tubliss or mousses with some enduro tires would be huge and then getting the suspension softer from EnduroSpec is amazing for rough stuff. Then you can throw the flywheel weight on to mellow out the YZ powerband a little bit. That would be a good start!

[@jt1573]

Light 2 strokes get bucked around by rocks and roots at speed. Having Tubliss in the front softens initial impact and helps the bike keep a straighter line.

[@SourceADV]

Agreed! And the steering stabilizer with a very tiny amount of low speed damping helps a lot!

[@ExploringCabinsandMines]

Those rims are pretty........

[@SourceADV]

Stock 2019 rims! Definitely pretty beat up from the rocks when you get close, but still good from 5-10 feet 🤣

[@PA-Tammy]

That Yam top end will out last a KTM buy far even the 4t Yams go forever I have a 08 with over 900 hrs and it's a stock motor less clutch pack and that is in rocky ST and open 2T.

[@liviosinibaldi3632]

Tons of more money.

[@SourceADV]

Got bike for $5k with one hour on it, sold it for $9600.

[@jonsmith9708]

you ask too much out a carb 2 stroke.if u wanted more predictable then get a fuel injected 4 stroke

[@SourceADV]

Honestly man, once that smart carb is dialed, I prefer it over my Fuel Injected KTM 4T. It is so simple and lightweight and it runs great everywhere. There is almost nothing that can fail that you couldn’t at least tweak or limp back on the trail.

[@whitetrashgarage8110]

Apex head with the XC dome, governor mod and a quick jetting adjustment and the thing feels like a 4 stroke but still sings... I wasn't a huge fan of mine until I did these things, now I friggin love it.

[@SourceADV]

@@whitetrashgarage8110 I have a few buddies that run that setup too and love it! The challenge in Northern Arizona is that we ride at 7-10K and at 2k feet, so that's why I went SmartCarb. Cheers!

[@whitetrashgarage8110]

@@SourceADV If I wasn't at a static elevation, I'd probably do that as well.

[@SourceADV]

@@whitetrashgarage8110 I wish i was at static elevation, would make things far simpler LOL! Take care!