Yamaha YZ250 & YZ250X Bottom End Rebuild | Part 1: Engine Disassembly

Yamaha YZ250 Engine Rebuild: www.rockymount...
This is part one in our series where we go through a complete bottom end engine rebuild on a Yamaha YZ250. The first part of this process includes the engine disassembly process, which is detailed here in this video. The steps shown here will be very similar for other late model Yamaha YZ250 and YZ250X bikes. Stay tuned for this series to see the complete engine disassembly and rebuild process.
Watch Next:
Yamaha YZ250 & YZ250X Bottom End Rebuild | Part 2: Engine Assembly
• Yamaha YZ250 & YZ250X ...
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[@crf450xripper]

Thank you so much for this video as well as the whole yz250 rebuild series! I purchased a used yz250 and brought it home and drove it less than 3 miles and the crank assembly seized. This series allowed me to rebuild it completely. I have about 15 hours on the bike since full rebuild and everything runs like a charm. Rocky mountain atv/mc fan for life!

[@SolePompano]

I did the exact same thing and I know shit about dirt bikes but I’m decent with my hands and decided to give this a go. Wish me luck! (I have the engine all taken apart just waiting on rebuild kit to arrive so I can build it all back up again!)

[@tayloreverett1265]

I'm literally watching the one from a decade ago thinking "man I wish they would do an updated one" as this dropped into my sub box. yall are the best!

[@evemiller3946]

This is the ost detailed video I've ever seen

[@rileyhers8670]

Videos like this is what KZbin is made for, these are lifesavers

[@meganbiaggi509]

In my dads garage he always map'd the fact that when putting parts away before putting them back together. that way you dont get lost going back to putting it back together and anybody trying to use your bike that you trust, your bike wont be totaled if not insured right. Your doing a good job other than all that.

[@JETZcorp]

I think this is the only video on the entire internet that shows how to clean mating surfaces, that doesn't involve someone wire-wheeling an iron Chevy block.

[@rdgsupafli]

The only thing you didn’t mention that was critical was removing or loosing up the tabs holding in the shift drum. That was the only thing holding me back at first and still worried about putting the transmission back in. Other than that great video without this video I wouldn’t even attempt rebuilding my motor.

[@rdgsupafli]

Nvm I figured it out my bearings were stuck on the shift drum that’s why it was harder for me to remove.

[@lip_rip_skijoshualipinski6306]

Funny coming across this now. I just split my cases lastnight. Not seized up but piston grenaded

[@thewanderingelliotts140]

Thank you so much for a great video. just tore my bottom end apart and your videos gave me the confidence to do it! Keep up the amazing videos!!!

[@rmatvmc]

That's what we like to hear! Glad the videos helped and thanks for the feedback!

[@bymat518]

Thanks for the video , this is why I shop at RMATV. Just got my bottom end kit , motor’s out, ready to continue to follow along.

[@rmatvmc]

Right on!

[@YouCantSawSawdust]

Just a tip on removing dowels without marking them. You can run a thread tap into the dowel and then use a pin punch to tap it out from the other side. The outside surface of the dowel will be unmarked and can be used again.

[@danielkeene-lopez3527]

Im totally not rewatching this and pt 2 everyday until my engine rebuild kit arrives in 2 days......

[@rmatvmc]

Probably a good idea! 😉 - Wes

[@danielkeene-lopez3527]

@@rmatvmc it worked for the truck, I have high hopes!!!

[@danielkeene-lopez3527]

@@rmatvmc great video btw!!!

[@peekingtom8337]

If the grooves are deep, you can file the basket down works like a charm

[@sendingit2601]

Just did a new top end on mine and I started hearing a knock from it. Time to drop anything 750 on it.

[@carsnails]

Great video. Thank you.

[@igorochakovski3124]

Thanks!

if you do not have clutch holding tool good thing that you can do is to take old clutch plate and just weld holder to it if you do not have case splitter tool you can screw a nut on crank and using hammer hit it slowly and cases will seperate and nut will protect thread you can do this from either side this methods work on any motorcycle kind regards

[@jondoe7901]

Damn, that flywheel is in need of some TLC. 😂

[@kyleburgess9175]

Thankyou!! Helped me heaps

[@shaidrencarter8719]

What can I use if I don’t have a crank case splitter?

[@Sustrii]

2009 and the stopper lever bearing was still plaguing us

[@shakiejake]

13:00 after you remove that little spine washer of the crank , is there anything else’s behind that? or just the seal ?

[@cbr600rrturbo]

Wheres Steve did he bounce?

[@marlattmotos]

Can't find parts for my 96 yz250. I had a hell of a time sourcing a cylinder sleeve and cylinder head for it.

[@Ls-rv6tl]

How compatible is this information for the 250f?

[@kirbylee57]

He said, replace the clutch basket if the grooves are very deep. How deep is "very" deep?

[@rmatvmc]

Any noticeable grooves are going to affect performance and action of the clutch. I'd say it comes down to your budget and how severe the grooves are. Any noticeable grooves should be repaired/ replaced, but if your budget doesn't allow it and the grooves are just beginning then you could decide to run it a little longer. - Wes

[@andrewmasaberg1116]

I have a 94 yz 250. Is the bottom end the same bottom end thats on the recent yz 250s ? I know the top end has a diffrent power valve re design.

[@premiumdetail5349]

My bike died on me yesterday while I was out ripping , and it just hiccuped or choked and slowed down . I thought gas ran out turned reserve on started right up , something sounded like it was jumping around. I’m not sure , but it died immediately. And I left it alone brought it home… now tryna figure what it is ..

[@LimaTangoZulu]

Something made it past my air filter and ripped the reeds, beat up the cylinder and piston, and seized the con-rod bearings.

[@utahenduro4808]

Forgot the clutch actuator arm bearings

[@argunzed]

Need help do you have videos of removing the stuck swing arm axle?

[@waynehalozan7124]

Get some dry ice on both sides of the axle - shrinks the bolt. Works on stuck bolts also.

[@eschrader]

That bike was ridden hard and put away wet more than once

[@HigherXFPV]

Is there a video of this being done to the yz450? Or is it similar enough

[@rmatvmc]

We have other bottom end rebuild videos on four strokes that will be similar. kzbin.info/www/bejne/oF7QfoCBgLKor9k kzbin.info/www/bejne/oYq7XpWFfJ6piJY

[@jdoggriffo3171]

That crank case spliter what brand is it and where can I buy it online

[@rmatvmc]

That is the Tusk Crankcase Splitter. The first link in the description will take you to a page with all of the parts and tools used in this video.

[@wanmuhammadfakhrullahwan8078]

👍👍

[@team2sick850]

Can you guys do an 07 cr250r

[@rmatvmc]

No promis, but I'll see what I can find. -Charles

[@team2sick850]

@@rmatvmc Thank you. I'd donate my bike for the video of you guys wanna give me that factory discount 🤣. Great Video regardless. This company is amazing.

[@Nebula1214]

I have a 2005 yz250 and the 5th wouldn’t normal like the other. When i gas it its stop and goes. Really hard to explain can you tell me what that is

[@joebauer6752]

shift dogs maybe rounded causing it to pop out of gear.

[@andreamorgades3988]

Preciso semi carter yz 250 año 96 soy de Uruguay preciso

[@johnmullins1034]

Mine has a oil pump and some kind of timing grar

[@Gooselessponds]

Not if it’s a two stroke

[@mikeS0162]

Where can I find the service manual for this bike?

[@rmatvmc]

What year is your bike? It looks like we don't have many service manuals for YZ models but you should be able to find an online version pretty easily with quick search. If you're looking for a physical manual, a good place to look would be eBay.

[@mikeS0162]

@@rmatvmc yes that's where I found one, thank you!

[@JohnBoyDeere]

I have to ask, why gloves when working on a clean engine? Might chip a nail??

[@rmatvmc]

Lol yes! We wear gloves whenever we do things with oil or chemicals. Do what you want. -Charles

[@JJM-f3h]

@@rmatvmc i took a couple hydraulics classes and the instructor said to wear gloves. He said finger prints will create rust on clean steel shafts. I dont recall further details.

[@billyizquierdo5707]

What mm is the flywheel puller?

[@rmatvmc]

This bike used the 27mm flywheel puller. You can click the link below, enter your bike's year make and model to see the size flywheel puller. www.rockymountainatvmc.com/parts/tusk-flywheel-puller-p

[@chadkartchner581]

what blind bearing puller did you use. I cant seem to find one that works

[@danielalbertoarechigaperaz7776]

Me encararía verlos pero no entiendo lo que dise 🥲

[@nastysoda9212]

I'm scared

[@YouCantSawSawdust]

Again with the nitrile gloves!!!! I swear KZbin won't allow mechanics to post videos unless you are wearing nitrile gloves. God gifted us with us with five basic senses. A good technician will rely heavily on his sense of touch to evaluate component condition,as you tried to do with the clutch hub fingers,as an example. Anything that reduces this sensitivity is detrimental to good analysis of components.

[@Distracted_driving_kills]

Do you have a video on replacing just the drive(countershaft)?