2003 cr125 Bottom End engine Rebuild Part 1

In this video I reassemble this cr125 engine in detail. If you guys enjoyed this video like and subscribe! Check out the cr125 playlist for more on this build series!
Help support the channel and get your Powersport parts and tools at The D Zone. Here is a link to my favorite tools that we offer- thed.zone/prod...
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Links to products used: (If you want to help support the channel so we can continue to create new content for you to enjoy, I encourage you to shop through these links.)
Heat gun- amzn.to/2V6hhZv
Temperature Gun- amzn.to/2DJlniV
Permatex Thread Locker- amzn.to/2tpY3Cg
Permatex Anti-Seize Lubricant- amzn.to/2DTLl3B
Maxima Assembly Lube- amzn.to/2TOc9Zr
Maxima Grease- amzn.to/2EcDKhD
Small oven- amzn.to/2EcEKCp

[@adampaganelli4891]

Thanks for watching! If you are looking for a way to support the channel consider shopping for your Powersports parts at The D Zone. I also put together a list of my most commonly used tools for you guys to reference- thed.zone/product-tag/tool-collection/?count=36&orderby=popularity&ref=AP34

[@joslinnick]

How big of a deal is it if someone tries rebuild an engine like this who hasn't done so before? I owned an RMZ450 and did a lot of my own maintenance (valve adjustments, brakes, tires, etc.) but not something this involved. I always wanted to own a 125 two-stroke, and I've considered buying an older model and rebuilding it, but I was a bit intimidated by trying to do some of the more involved engine work. Watching this video gave me a lot of renewed confidence.

[@adampaganelli4891]

Glad you have more confidence on rebuilding it now! If you follow this video you should be fine just requires around 4 or 5 specialty tools. And I’m always here for questions along the way!

[@joslinnick]

@@adampaganelli4891 Thanks for the response! I'm glad to know it isn't too difficult. With all of the older two-strokes out there, these full re-builds are becoming more necessary to ensure that the bikes can keep running.

[@2DclanSnipingTeam]

@@joslinnick , And a factory service manual will walk you through it. It's a great $59 investment.

[@samdouglas1842]

IF YOU ARE USING THIS VIDEO TO REBUILD YOUR CR125R, READ THIS! Don't mean to be that guy but I just spent 3 days trying to figure out why my transmission wasn't shifting even though I followed this video exactly. The top gear on the output shaft is upside down. I only found out because I finally looked at the service manual. Split my cases 3 times haha. Other than that, this video is great.

[@wotever99ninynine]

thanks man, great video. very thorough, this is going to be very helpful soon when i start my rebuild on my 2001 cr125. i have a slipping 3rd gear, all other gears are fine and i stay out of 3rd to prevent further damage so hopefully all is well and its just a new shift drum/ forks. maybe one gear..

[@varney7]

hi, i have just encountered the same problem with 3rd, i think its slipping but theres no crunching sound or any sound when slipping just the bike jerks arround is this same for you?

[@wotever99ninynine]

@@varney7 if there's no sound it could be clutch slip but you should be able to feel that in some other gears too. Mine makes a little metal noise, the power catches and drops. On/off. I'm not really sure what my problem is until I take a look, so not sure what yours could be either.. Sorry

[@wotever99ninynine]

@@varney7 but yeah it does jerk around. When it first started happening it would only do it once about 3 quarters through the power and in 3rd, now it's on and off/jerky. Or maybe just does it each time you go off the power and back on, I havnt ridden it in 3rd for a while so my memory of it isn't brilliant

[@leahgittins7650]

wotever99ninynine Hamilton did it ever feel like the bike was slowing down reallly quick wen off throttle in 3rd almost as if you were breaking

[@wotever99ninynine]

@@leahgittins7650 yeah, but only for like 1 or 2 seconds before it grips again, then slips again etc

[@AppalachianMotors]

Is it bad that I am more comfortable rebuilding an actual car engine like the jeep 4.0 straight 6 or chevy 350 v8

[@AppalachianMotors]

They are just so little and seen so delicate

[@wasabiemans]

@@AppalachianMotors nah ur just more comfortable with cars

[@XJonAye]

That’s just because you have practice with the larger engines, I’m after you do this a few times, you’ll be doing it for fun

[@FULLTHROTTLEFILMZ]

Great video so much helpful information. I'm going to be rebuild my 2003 cr250 engine in a few weeks.

[@adampaganelli4891]

Thank you! Best of luck on your rebuild, let me know if you have any questions

[@dmitriystepanchuk9946]

I'm rebuilding my 2003 cr125 currently. I'm in the same spot you are so I'm hoping part 2 will be up soon.

[@bladez2107]

At about 20:45 the gear on the secondary shaft do you have that backwards? In my manual it shows that it is. I have a 2001 cr125 and if you spin that gear the other gear is able to slide into it if that makes sense. I just don't want to reassemble mine wrong.

[@AdamzGarage]

I know this question was from 5 months ago, but I have the same question, did you fix that or am I looking at it wrong? Thanks.

[@Dylans503]

@@AdamzGarage deffinately backwards. Don't do it like him lol. That cut outs there for a reason.

[@ethannethery2]

Adamz Garage yes they are backwards always refer to your manual

[@Bryankimsey]

Really good video. I'm about to put my '04 KX 125 back together and wanted to see the gears in operation. Got that. Lots of good information on the assembly lube, grease, and anti-seize, too. Many thanks!

[@mastmec]

instead of a sanding block, use a flat surface like glass and layout wet sandpaper and lay the case down and run figure 8's and it will be a true flat surface. great video.

[@2DclanSnipingTeam]

I was gonna say that. You beat me to it. Cheers.

[@conehead1047]

I like to use a piece of couch cushion and sand paper

[@XJonAye]

Thank you for doing this, it’s one of the better videos I’ve seen so far. I especially like how you throughly identity each part and your process.

[@jackrayner6715]

@25:15 i cant for the life of me find neutral, anyway i turn the barrel both shafts spin

[@chrisreinhardt5136]

I've done about a million CR125's, I've built them for shifter karts, high reving etc.... Very important to get the seals straight, perfectly straight, not eye ball straight. You don't need to pack grease behind the seal, it's only going foul a plug. Grease around the outside, very important, every seal gets grease on the inside to break it in...

[@socks2441]

28:10 somebody just dropped a ping pong/ table tennis ball on the ground, lol

[@wyatts485]

When you but the 2 cases together do you need to use the crank puller or can you but the bolts in to but the cases to each other

[@socks2441]

did you have the hot rods crank tested to make sure its trued? and do you know how well it has held up etc? ive heard bad things about aftermarket cranks, mostly wiseco but also hot rods. im looking at a rebuild. i found a bottom end rebuild kit that has a crankworx crankshaft though but ive never heard of that brand and cannot find anything about it on the internet. not sure whether i should stick with my current crankshaft, rebuild it, or replace it with an aftermarket one. i only split the case to fix a transmission issue, but might as well replace other things while its open.

[@Charlesgaming1000]

Hey man this video is awesome.👍🏼👍🏼. I'm doing a CR125 bottom end in the next few days. I'm just waiting on the wrench rabbit kit in the mail. I'm very glad I watched your video because I thought I was getting all the bearings in the bottom end in the bottom end kit. Can u please reply and tell me which bearings aren't in the kit that I have to order?

[@travismaniagigglebush247]

Dude ur solid epic video s perfect thank u man I'm flying thru the transmission on my 88 cr 250 after getting it all right thru ur videos

[@MrBabe1990]

Hy Have you a link for this rensh rabbit kit pleace i Have a honda cr125 bj 1988 im from germany

[@TWITCH772]

What manuals are you using to do this? They appear to be much more detailed then the service manual (comparison to my 2001 cr250 manual)

[@noone3734]

I've never done this and I've only watched a few videos about it, but putting the bearings in the freezer seems like a mistake to me. Also what if you left the bearings room temp for installation and gave them a generous coating of that assembly lube before dropping them in? I want to learn, this stuff really interests me. Great work man.

[@losantonio9049]

Give us your review on this particular rebuild kit please. Thanx!

[@losantonio9049]

I've had this kit here for one week and I am about to return it. The crank is constructed with several parts as opposed to oem wich has a solid construction. The connecting rod has one hole for oil passage to lube the connect rod bearing as opposed to oem which has two holes for oil passage on the rod. The oem piston has four oil passages to lube th wrist pin and this kit has no passage for lubrication of the wrist pin. Head gasket holes don't line up. Please share your experience with the viewers on your post build experience. Unless they sponsored you which then I could understand why you couldn't share this info

[@huntercoleman4302]

You can also get cans of air for cleaning out computers, turn it upside down and spray the bearings it will freeze them very quickly just make sure you spray the bearing after installation with wd-40 so it won’t rust

[@antoniusmilesdale6120]

Super video. Just got a cr125 to work on in a box. Luckily all the parts are there. Video helped a lot with assembly.

[@adampaganelli4891]

Glad it helped! Thanks man!

[@jaynotfound9414]

I’m doing my yz125 and can you freeze the crankshaft and it won’t rust? And the bearings?

[@5thgearpinned450]

Where can i find a cylinder with the powervalves. Ive been looking but i cannot find it online and no ones selling onee

[@chrisheath7500]

Adam what chemicals do you use in the cleaning tank? Thanks. Keep up the killer work.

[@mind.hacker9996]

Hey just wondering how the hot rods crank and main bearing are holding up would be great to get some info since I've heard hot rods crank and main bearings are trash thx

[@gabeallen7262]

Great video! What assembly manual did you use? I haven't been able to find one anywhere.

[@adampaganelli4891]

Thanks Gabe! I used the Honda one. I googled 2003 Honda CR125r service manual and printed out the pages. What bike are you looking for?

[@gabeallen7262]

Ok. I don't know why I couldn't find it then. I only need the service manual for the transmission, because I'm using it as a transmission for a 10HP Briggs and Stratton.

[@greisoncarvalho4450]

Quero comprar a caixa da CR e nao encontro

[@loganprice2197]

those 2 bearings that you had to order oem what website and part number did you order from? I'm currently rebuilding my 2004 cr125 and I am having trouble finding those 2 bearings

[@a.j.dasilva578]

Partzilla has them bearings I had bought a set from them. I know this and old comment but just wanted to let you they have them

[@samualmiller1259]

A.J. Da Silva you know the part numbers

[@a.j.dasilva578]

Samual Miller yea the part number is 91002-KA4-003. If you need anymore help just send me a reply.

[@grider9724]

is your top trans hear upside down

[@adolfoperezlobato374]

(Wiseco o hods roods) calidad?

[@joelhodge3113]

Great video thanks.

[@temisweey3358]

nice video, cant wait till its done!

[@adampaganelli4891]

Thank you very much!

[@windshieldrepair5961]

How did you split the cases"......Did you use a special tool??....Installing the bearings went very smoothly with the heating and freezing process!!

[@adampaganelli4891]

I have a video on tearing down this engine where I talk about splitting the cases

[@NotTooHasty]

Will I be able to put a 2005 cr125 engine in my 2003 cr125 frame? I'm trying to rebuild my 03 cr125 but I need a motor for it. Haven't been able to get my hands on an 03 but I have found an 05. Does anyone know if it will work? Thanks.

[@aussiehonchar3606]

hasty 765 it should

[@baldmike500]

Great job with your videos! I'm starting my 2002 cr250 project this week android am wondering which crank you would recommend (Wiseco or hot rods) I'm not ordering parts until I tear it down. It has a Hot Rods crank and a Wiseco piston now. I can see you build a lot of bikes and just thought you might have a preference. Thanks for the great videos and cheers from Alaska!

[@aaroncrain2343]

Probably too late now but I would only use OEM cranks or Pro X cranks. I’ve heard too many crank failures from wisco and hot rods cranks

[@danshealthylifestyle8443]

Hey man miss your videos when your gonna post again

[@250race]

Just a head up you should never use 7 ball bearings on your crank bearings they are made in China and do fail. Same with hot rod or Wiseco cranks, wrist pin bearing On these you should alway you stock OEM You should alway use Koya 8 ball bearings Good build bud

[@antoniusmilesdale6120]

Never had a seven fail but that's just me. On all my 250s the smaller output bearings fail first and cause chaos.

[@Buffetology]

Hey boss, where can I get the schematics you have to put the engine together?

[@korylewis7858]

HEY DID you pack all the seals with grease?

[@gabrieldoyle3352]

Rebuilt a cr 125 engine ran so good thx

[@a.j.dasilva578]

What kind of crank comes in the kit, I’m about to rebuild my bottom end on my 2005 CR125r so like the same as yours

[@adampaganelli4891]

It’s a hot rods crank!

[@bunny_six]

😊

[@XAllky]

Awesome Video!!!! Thanks for taking the time to make this happen

[@Chippyd363]

enjoying these makes me wanna go for a rip!!

[@Blocanbentlyyahu]

Would this be the same on a 4 stroke?

[@a.j.dasilva578]

Hi I’m doing a similar build and was wondering for you had put that last countershaft gear on up side down? In the manual it shows the windows down after 2001? If you can answer me back it be much appreciated thanks, great build too.

[@jaredkint1385]

Im doing the same rebuild and i noticed this as well. You even see wear on the final gear as if it was originally set the other way.

[@a.j.dasilva578]

Jay kint yea the Gear windows face down that’s how the Honda manual says to do it. I did mine the way the manual said to. My bike is fine. I’m sure Adam caught it and flipped it over before pulling the cases together. If you have any other ?’s Fell free to ask.

[@floridalottery3134]

OEM

[@PC-91]

Very informative video series, thanks a lot!

[@adampaganelli4891]

No problem, it was a ton of fun!

[@zaczito6698]

How did the hot rods crank hold up!?

[@jameiontaylor6207]

Can someone help me with locating the part 3 video on this project please.

[@Blocanbentlyyahu]

How can I tell the torque specs

[@Inc0rr3ct]

This video is so so amazing dude

[@2sikxd]

Overall would you recommend the wrench rabbit rebuild kit?

[@michaelholden8667]

End and top end kits in all 5 of my 2 strokes dirt bikes no trouble what so ever wisco is number one in my book you cant beat wisco products same way I only use boysen racing reeds they perform so well when you touch the throttle quick response it really comes alive the power band is awesome can't beat boysen racing reeds and use vhm racing head on all my dirt bikes makes more compression and horsepower

[@kirilduldurski2980]

Part 2 ? :D

[@adampaganelli4891]

Editing it right now should be up by Wednesday at the latest

[@adampaganelli4891]

Part 2 is up

[@natechilds6432]

A rude joke is put red lock tight in the engine assembly lube

[@wotever99ninynine]

that is downright horrible.. :-)

[@SOLDOZER]

You dont need assembly lube all over your transmission. Thats what you engine oil is for.

[@adampaganelli4891]

The engine oil takes about 5-10 seconds to reach everywhere in the engine after being rebuilt, trying to reduce where and cover what I can

[@nickhandcock7515]

It's called assembly lube for a reason. It eliminates dry starts and damage to seals. It's an absolute must when it comes to rebuilding things with lots of moving parts

[@antoniusmilesdale6120]

Tip the motor upside down first :)

[@occif2023]

Hi Adam, I am doing this exact motor right now and cant find the missing bearings from the Wrench rabbit kit @ 5:27. Do you have the OEM part numbers ? Both suppliers I use show these as discontinued and not listed so I cant get the correct OEM part number from their website either. Also, I cant wait to see your work on Jeff walkers engine. I appreciate what you do, Thanks...

[@samualmiller1259]

Did you ever find those part numbers

[@occif2023]

@@samualmiller1259 No. I took it to a supply house near my house and had them match it. www.bearingheadquarters.com/ . Then cracked the case while pressing it in so I bought a new complete motor and figured I would deal with it later if I ever rebuild the motor. I would recommend not even replacing them unless they are shot.

[@samualmiller1259]

Do you know the size of bearing or any part numbers or anything? I’m gonna try my local Honda shop.

[@occif2023]

@@samualmiller1259 Do you have your old bearing ?It is stamped on it in very tiny numbers. I will look when I go out to the shed later today. I think I still have the box that it came in. I do remember that there were several options in that size too. Fully enclosed, half enclosed and open on both sides.

[@occif2023]

​ SKF Single Row Ball Bearing 607 . I honestly would take the case to a Honda dealer and have them order the part. I believe this is why I cracked the case because the bearing was not correct .

[@emppuviljakainen3726]

When does the part 2 come?

[@adampaganelli4891]

Part 2 is in the works should be up within the next week. I had shoulder surgery so it has been longer then I was hoping. Thank you for you patience

[@adampaganelli4891]

Part 2 is up

[@ernestocervantes8825]

Part 2 ?

[@adampaganelli4891]

Ernesto, part 2 is in the works

[@adampaganelli4891]

Part 2 is up

[@Jan-tm7jd]

Dude you doing so well on such videos. Please keep on!

[@adampaganelli4891]

Thank you for watching 🤟🏼

[@UlisesGlez26]

Good job bro, it's going to be a sweet bike, hope you could have a ride with CN soon with your 125's Cheers from Mexico.

[@adampaganelli4891]

Appreciate it!!

[@garrettgifford9709]

WD-40 kills bearings, it’s a degreaser and will wreck a bearing

[@adampaganelli4891]

Exactly, I installed for rust prevention then added assembly lube for lubrication

[@will.134]

WD40 WATER DISPENSER drives out moisture

[@antoniusmilesdale6120]

Where did you hear this? We've been using wd since the trike days. Wd is the gentlest stuff out thete.

[@agentofenhanced2428]

Antonius Milesdale watch fortnine’s video

[@deanofakesie8153]

Can you use gearbox oil instead of assembly lube

[@adampaganelli4891]

Deano, the point of assembly lube is to stay on the parts for long periods of time as engine oil would drain off. If you were starting the engine pretty soon after a rebuild that would work just fine

[@deanofakesie8153]

Hi mate, i meant can u squirt gearbox oil on the bearings instead of assembly lube, but I guess u knew what I meant and and the Q .. Keep up the good work mate

[@ic9049]

Part 2?!;)

[@adampaganelli4891]

Editing it right now sorry for delay

[@adampaganelli4891]

Part 2 is up

[@trufi18]

Hey man, at 17:00 doesnt go another tab for the other bearing in that groove??

[@adampaganelli4891]

No there is a tab for the other case side but not on this side.