Yamaha YZ250 Big Bore Kit | YZ300 VS YZ250 Ride Review

[@rmatvmc]

Cylinder Works Big Bore Kit: rmatvmc.link/cylinder-works-big-bore-kit-yz250

[@abj5609]

I love YZ's, but if you are looking for a 2 stroke for tech, just get a European bike. Even more low end then an YZ300, e-start, counter balancer. The only reason to get the YZ was suspension, but the 23+ Austrian bikes finally have good stock suspension. Plus Beta and sherco have the same KYB as the YZ. Just my opinion after riding both.

[@MustRideMoto]

Excellent comparison, fun to watch. I never watch vids for more than 10 minutes, I actually watched the entirety of this one!

[@Zulululu4x]

Yeah. The attention span of most folks nowadays is alarmingly wild

[@rmatvmc]

Thanks for watching! This one was super fun to make

[@dustinkeim179]

Thank you for making this video, that kit will be great for serious woods riders

[@ivnepe]

Thank you for a true review. Keep going

[@rmatvmc]

You're welcome! Thanks for watching!

[@ottokirk2325]

You can save money by installing the HITLIS power-valve kit. All the users are raving about more power, but electric smooth. Ask Cody Webb, now on Yamaha.

[@ottokirk2325]

For unstoppable low end and the power of a full built race engine. I went with the STIC SuperX carb and zero engine mods required. Even 125's will lug up steep trails without xlutch input. A trail character must be specified, otherwise It's necessary to de-tune full MX power delivery.

[@CP-qx2ff]

Informative review, as the 300 is better in technical terrain it would have been interesting to see it compared against yz250x.

[@rotorhead5000]

The conclusion is about the outcome I expected, interestingly though a buddy of mine recently did this kit on a fixer upper he got, and im dead convinced his tune is a little off. Thing just doesn't seem happy until he comes into the pipe a bit, we'll see what a bit more fiddling with it does.

[@mikeking7388]

Maybe some jetting changes? I figured it would be that way to be honest

[@rotorhead5000]

@mikeking7388 That was my thought, aforementioned buddy more thinks about tuning in maximizing that 2 smoke power hit when it comes on the pipe, which is great, but for a woods bike, being able to function below that range is pretty important.

[@mikeking7388]

@@rotorhead5000 yeah for sure! I used an Mx yz250 for woods/hard enduro for just under 300 hours. If I had my time back I should have bought a 300 kit after one of the rebuilds.

[@MatthiasVermeersch]

intake spacer is in the wrong place on the 250... and fmf pipe vs pro circuit is also a difference in performance

[@dcfilms347]

Please get these back in stock I have been waiting to order one for my 03 yz250 rebuild for 2 months thanks

[@rmatvmc]

We hope to have more in-stock soon!

[@InTheDirtAgain]

I have a 99 KX250 that has a full woods conversion with the KLX gearing. Love the response and how snappy the motor is, but it will never tractor like my 96 KTM 300. Also, I'm already on the pipe at 45mph with 13/52 gearing. It really needs a 6th gear for desert or fire roads because I'll lose what little bottom end it has if I change my gearing up. Would love to try a 300 kit on that bike. Track means nothing......take it to the mountains on some gnarly single track or technical hills and see which you prefer.

[@rmatvmc]

A 300 kit will definitely get you that bottom end you're looking for. Thanks for watching!

[@brucemorrison3563]

How about a flywheel weight?Should that make it even better at lugging on steep rocky terrain?

[@rmatvmc]

Yes a flywheel weight can help with the lugging on steep rocky terrain.

[@DanielStahler-m8f]

Big bore kits work amazing with aftermarket ignitions

[@AngryyBeaverr]

A 250 is a lot more snappier and fun than a 300. A 250 2 stroke is the perfect bike that’ll keep you scared but have the most fun at the same time

[@KaneSlayer414]

Agreed. Until you hit some technical riding. Hard Enduro ish stuff. Otherwise a 250 is a blast

[@rztrzt]

Those 300 kits take the grin factor out of the YZ.

[@jacobbieler1876]

All 300s are that way. 250 for life

[@LifeWideOpen780]

That's kind of the consensus. I think the airflow of the cases and everything is designed to be a 250

[@mutt2jeff]

Lol at the KTM 300 having a cult following, it's not a cult, it's the standard of off-road 2 stroke 😂

[@vince5946]

Do you have to modify the governor with this kit? Is the big bore kit a Nicasil or cast iron bore?

[@rmatvmc]

We didn't modify the governor. The cylinder itself is made from an OEM grade aluminum casting with a nickel silicon carbide cylinder sleeve.

[@Supply_65]

How’s vibration?

[@TwistandShout257]

Just like any other YZ! You feel it through the pegs, seat and bars 😂

[@rmatvmc]

Yeah it's the same. 😂 Hope you liked this video just as much as we did! Thanks for watching!

[@CaseyFord-hd9ls]

Has anyone tried this kit on a 250x? I assume it would fit, but it is not advertised for the X. I am curious if the porting and compression would compliment the x in slow technical stuff, or is this more of a "race" kit?

[@morley3810]

So...is the piston actually off the shelf from some other application? Or are you stuck with the cylinder works piston? In other words, is the piston bespoke by them for this kit?

[@rmatvmc]

The piston is made by Cylinder Works for this kit.

[@YZ250ama]

I have videos and jetting on my yz300. mine rips hard for racing , pump gas.

[@toddsorel-pg4hr]

But the 480 kit is even better.

[@rmatvmc]

I take it you've tested out the 480 kit?

[@dustinkeim179]

I wonder if a stock head will fit on that jug

[@rmatvmc]

No, but the kit comes with everything you need. The squish and shape of the head are really important for the bike to run correctly, and the head that comes in the kit is very different. -Charles

[@dustinkeim179]

@@rmatvmc thanks for the reply

[@Slane583]

I think Yamaha has kept the YZ the same for so long because it just works. It's not the best, it's not the most powerful and it's not the most advanced thing on two wheels in the land of 2-stroke. Compared to the European bikes it's the most affordable. Probably the most reliable and there is tons of mods to make it however you want it. Plus Yamaha is the only one out of all of the Japanese brands who is still making two full size 2-stroke mx bikes. Where as the other three have moved on to making fart bikes for their full size machines. Kawasaki on the other hand has only decided to keep 2-strokes for their small displacement KX's.

[@rmatvmc]

You can't really go wrong with a YZ!

[@Slane583]

@@rmatvmc Nope, you can't go wrong. I have a non-running vintage YZ465 project I need to someday get to along with an IT400. As much as I'd love a newer YZ250 I think I'm set for bikes once they're both running. :)

[@Randy_Cox]

Back to back lap times only show any difference if the rider is so good one bike hinders his performance. I have done back to back laps times on my kx450x and my yz125x and they are no noticeable time difference and I am not faster than either bike. 😂😂 Now if you wanted to talk about ease of riding or energy management because you don't have to shift as much then maybe you can put an edge to that.

[@edsimon3754]

Rktek head , call it a day

[@mothridith9760]

First

[@sambourre9539]

You guys sell everything, put same exhaust system. Not equal