Yamaha YZ250 & YZ250X Bottom End Rebuild | Part 2: Engine Assembly

Yamaha YZ250 Engine Rebuild: www.rockymountainatvmc.com/Sa...
This is part two in our series where we go through a complete bottom end engine rebuild on a Yamaha YZ250. The second part of this process includes reassembly of the engine, 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 1: Engine Disassembly
• Yamaha YZ250 & YZ250X ...
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[@dericnichols6804]

Charles, I know I speak for many when I say "THANK YOU" for making this and your other videos. Without this video I wouldn't have done my own rebuild, You have a way of explaining the little details and the quality of your video is by far the best.

[@rmatvmc]

Thanks Deric! We try hard to make these videos good, so I'm glad it helped! -Charles

[@redtobertshateshandles]

Pretty cool channel. Free how to videos. Amazing 👏.

[@GearinSuper]

This is one of the best step by step rebuilds I have seen. It will be my go too. TY

[@zbyh1980]

This is gold. Thanks for taking the time to make this video.

[@rmatvmc]

It's our pleasure. Glad it was helpful!

[@phillsmith5100]

I’ve just done the gears today for the first time and you made it look easy, took about 10 times for me 😅

[@shakiejake]

I have ordered everything to rebuild my engine , I do have many car engines and top ends on 2 smokers , but not much bottom end , tho video has took all the worry’s away thank you

[@vince5946]

great content, this will come in very handy on my 04 YZ250 winter build.

[@loganflorida462]

Keep them bottom end videos coming! I think we’d like to see some yfz content 💯

[@carsnails]

Great video. Thank you.

[@ellenpicardi6767]

After assembling the shift shaft we cycled through the gears. Sometimes didnt feel right. What are we doing wrong?

[@morley3810]

I watched it with the sound turned down and I appreciate that you showed that it's important to put red loc-tite on all the bearings before final assembly lol (yes, sarcasm for those not sharp enough to pick up on that).

[@rmatvmc]

LOL

[@jimberry742]

Outstanding...Thanks.

[@gasi9613]

Nice skills !

[@johnnymoe1989]

Did you put the water pump gear in? I’m doing this for the first time and feel like I’m left with spare parts and am confused. Thanks for the help.

[@jimbob12382]

Brilliant videos

[@benjaminsanabria5212]

Hey Rocky Mountain I just did a full rebuild on my 2007 yz bike is running nice but noticed antifreeze is coming out of radiator cap never saw this before please help

[@rdgsupafli]

What type of grease are you using for this? I have lithium grease at home is that ok? Or is it specific bearing grease?

[@AlexB-ts8oo]

What did you guys use to clean the crank cases? Those came out looking fresh, almost looked like that new top end lol.

[@Logoskates24]

Need help finding all the bearings for the cases . how do I know the size and how many I need ?

[@tim5618]

The left part of my case won't go in with the puller but the right will when I pull it wirh the puller and at first I thought it was the transmission but I don't know now. What is my problem?

[@ethanhering1309]

Will red locktight work instead of blue?

[@joebauer6752]

he mentioned pin on shift drum is positioned top /right but he rotates in hand and installed it on bottom side...what is right??

[@mattbandarra9574]

Did you use locktite on every bolt and screw or just the ones you mentioned? Not sure if you used it off camera on some

[@Seryoga_77_]

After the two halves of the motor are pulled together, it is actually necessary to check whether the shafts are spinning. There was a case that all the bolts of the halves were tightened, and the shafts did not rotate. With a full screed of the halves, it is necessary to control their ability to rotate all the time.

[@PERTHSCOOTER07]

Can the engine be fitted into the frame with the cylinder installed.

[@primerecording2337]

Yes

[@MrJeffharper47]

When did Fox Molder leave the X-files and start building dirt bikes?

[@William51115]

Why is the torque in inch pounds sometimes and foot pounds other times? Is it a big deal that I torqued everything in inch pounds by accident?

[@Joe-wy2bn]

I've got a feeling I might be doing this soon. I bought a yz250x with 120 hrs on it and it sounds a little "tappity tappy" from the bottom. Sounds like it makes a little crack or snap sound when I apply throttle with the clutch out. The foot pegs vibrate a little, but the bars don't, so I don't know...

[@SolePompano]

Do it. Last thing you want is a blow up which will cost you more and complicate the rebuild. 120 hours is in the range where you’d want to do the rebuild anyway.

[@newwavepressure6478]

Is this the same for 2001

[@bramvanhautte5112]

How long do you have to keep the bearings in the freezer? I see you laid them out and then started heating the cases. Don't the bearings become bigger again which makes is a snugger fit?

[@rmatvmc]

Many people will leave them in the freezer overnight but a few fours should do the trick!

[@redtobertshateshandles]

No, they're freezing cold. They don't warm up that quickly.

[@95jersey]

how can I hire this guy to rebuild my YZ this summer...

[@luistenas6321]

I have a Question. So i just put my cases together and I didn’t have a crank puller, the guy I bought the bike from had already pulled the crank into the left side of the case and when I put the right side on it just went in together without any force and I put yamabond, the bolts and it came together. Would that be a problem?

[@luistenas6321]

Flywheel and stator were already on the left side so when I put the right side just went in very easy, please help idk if I did it wrong.

[@rmatvmc]

@@luistenas6321 Hmm.. it should be a slight interference fit so there is no play in there. Do you mean you pulled it together with the bolts? Or did it seal up against the other case half before you installed the bolts? Was it a new bearing? -Charles

[@luistenas6321]

@@rmatvmc hello, yes it sealed up against the other case half without the bolts. Then I put the bolts on and it sealed up perfectly. all bearings were new. Do you think this might be a problem? Also I got a question my power valve is getting stuck, what would cause this problem? I took it out and cleaned it, but now it’s gettin stuck. What should i do?

[@TroNPopz209]

@@luistenas6321 I would make sure all your parts fit your bike, and are properly moving.

[@MountainManKm]

If I have case gasket I just put it on and torque it down right?

[@jesseleonard1429]

no , you have to spit on it first

[@MountainManKm]

@@jesseleonard1429 😂 thank you

[@redtobertshateshandles]

I'd file the grooves out of the clutch basket. They can give you a weird intermittent clutch slip problem if they're bad enough.. Great video though.

[@premiumdetail5349]

Hello my bike stopped running , when I started back up (literally one kick no issue) it sound like something jumping inside and turned off 😞 carb was rebuilt and adjusted then this happened when I rode one day for about 45 mins

[@jesseleonard1429]

bottom end connecting rod bearing

[@GodlyGreek5]

Hey mate hope you see this your video was awesome appeciate the effort to do it. there was a bearing with seal I didnt have it right spot lucky i could use your video for reference im a mechanic by trade but for a guide i enjoyed the video very well done. by anychance was this a yz250x? because i found minor differences on certian parts on my engine which is from a 2010 yz250.

[@rmatvmc]

Awesome, we're glad this video was useful in your rebuild! This bike is actually a 2009 YZ250 so that's funny there were differences. What did you notice?

[@GodlyGreek5]

Stopper lever assembly the roller on mine was smaller and on my photos I took I noticed a collar like a U shape that went around the roller and my roller was smaller then yours. your one was big and you didnt put anything around it or behind it. the roller hits on the cam shift segment. thats all i can remember off the top of my head I think their was one more difference but ive forgotten stressfull day for me truck mechanic life.

[@AREA-51moto]

A couple those torques numbers are way to high... better double check your manual for torque values , before you possibly strip out a of thread. Other than that, AWESOME video! Thank you so Much!

[@chadkartchner581]

What is that blue spray lubricant you’re using

[@chadrides914]

Looks like fogging oil for outboards or jestskis.

[@matthewlidel4324]

Is it normal for oil to drip out of the power valve vent hose.?

[@rmatvmc]

That is pretty common and that is what the vent hose is there for, but you may want to clean your power valve more often and/or find an premix that produces less buildup.

[@matthewlidel4324]

@@rmatvmc what premix do you Recommend I have a 2023 yz250x using yamalube now at 32:1

[@gabegunter7675]

Do you have to remove the tranny assembly to replace the crank ?

[@jesseleonard1429]

yes

[@mapiewsutisna4774]

👍👍👍👍

[@Jamie-Dean-007]

Can we use fluid film for assembly lube or is it different than the Yamaha stuff

[@lozadazx14]

And a ktm too please !!!

[@rmatvmc]

A bottom end? Which KTM? We have some Husky 450 stuff that will be coming out soon! -Charles

[@lozadazx14]

@@rmatvmc 300 xc

[@coloradodirtbike5930]

@@rmatvmc how about a kx500 or a cr250 👍💯. Great video by the way.

[@coloradodirtbike5930]

@Jaedon Humphrey 👍 right on

[@cheto2952]

You know if you don't talk so much after you pull the bearings and crank out of the freezer they will just drop in the case.

[@aleksanderdang6899]

Forgot case gasket??

[@omarvillegas7161]

You guys sell tools cheaper then Amazon on some stuff then the case puller is over priced. There’s se real company’s same exact tool with their brand on it or blank same colors exact thing. But half the price.you should keep the cheaper ones in stock instead of the tusk version.

[@jackl3384]

Is there any other way to install the crank? I can't afford a 200 dollar puller that I am only going to use once

[@chadrides914]

Then likely you can’t afford to ride a dirtbike either. Too expensive of a hobby for you. Good luck in your endeavors.

[@omarvillegas7161]

The same one tusk sells , 10+ company’s sell also. Lots of these companies are using all the same stuff for bikes, go on Amazon and they have some for 80$ a kit with the case splitter and crank puller same exact colors and designs

[@chadrides914]

@@omarvillegas7161 F’ Amazon and the people who encourage its use.

[@omarvillegas7161]

@@chadrides914 GOOOO AMAZON DEALS

[@omarvillegas7161]

@@chadrides914 the besttttt

[@Briank-ef5iq]

Weisco cranks any good?

[@rmatvmc]

Yes, Wiseco makes solid cranks and other engine components. We have reviews on our website where you can see what other customers think of the Wiseco Crank/Bottom End Rebuild Kit. www.rockymountainatvmc.com/parts/wiseco-bottom-end-rebuild-kit-p

[@jayr320]

Oem is same price you just don’t get free bearings or gaskets. Don’t bother. Everyone said they blew up quick

[@MTnumber11]

At 22:52 the pushrod is installed deep enough to be at least flush or slightly below the lip. Mine is sticking out a half inch and won't go in. Any ideas?

[@djfrankieflowers]

Whoch permanent loctite is that?

[@easternyellowjacket276]

Blue.

[@ivanstravels1109]

I'm the only one who noticed that you forgot to put a case gasket?

[@mc9304]

Yamaha don’t have one

[@Martinkeaton_07]

You put that spacer on for the primary drive gear... you didn't install it correct.. you must put your primary drive gear then the spacer then the water pump gear

[@user-si6ov8ui8w]

I checked the schematic, the video is correct. Almost gave me a heart attack.

[@aaronsaenz5370]

Bruh

[@noduh736]

How much would this cost at a shop if I brought it disassembled and cleaned

[@DisruptiveUnicorn98k]

i see you forget some haha

[@mikeking7388]

Im the sudden spike in views 😆

[@rmatvmc]

At least you'll admit it ha ha ha! Thanks for watching! - Wes

[@ankrapek12]

i give that crank about 13 hours before it fails like all wiseco cranks! trash products

[@yamaha4902]

Why not put the top end on then install the engine?