00' YZ250 Re-build

J-man67 · January 16, 2013

Bought a 2000 250 back in March. It was in great shape and appeared to be taken care of.

3 rides later BOOM! I am not blaming this on the PO. He said he did a top-end a few months back. I put about 15 hours on it. He did sell it as an 01, but found it to be a 2000 once he FINALLY sent me the title. Oh well, 1500 for a decent bike so I was happy.

Anyway, I was trying a new trail some buddies made at our spot and the bike just bogged down. 3,000 kicks later I just got my truck and loaded her up. Got home and started tear down. At the time I only had a small storage shed. IT SUCKED to work in, but got it torn down to find out the problem.

Now, I have a MUCH BETTER area to work on and store the toys as well as riding space!!! Sorry, first home purchase so very excited!

This is what I found:

Scored cylinder, ripped/cracked ports, power valve had a bite out of it...just a mess!

Piston has seen better days.

Head too:

After getting the power valve dis-assembled, I think I found my problem. Appears that the stop broke, made its way into the cylinder and wreaked havoc. Well, thats what I thought, but I found that piece in the power valve chamber. Maybe the valve was then able to make its way a little further into the cylinder where the piston struck it. Not sure as when the motor died, it wasn't violent. Just slowly lost power and died over about a minute. Feel free to speculate. Although, just thought back to when I added a flywheel weight. With the flywheel off, I could feel a slight movement in the crank. BAD BEARINGS. I guess I did not remember this until now b/c I knew it was a bad idea to run it like that. OK, well glad I got that cleared up for my own sanity.

Nasty in there...

This is where I stopped back in April. At that time, I did order all of the parts I needed/wanted to re-build, but thats where it haulted. Just busy busy busy. 2 small kids, work, bought a new house. Just no time for extras. I ordered a new cylinder, head, top and bottom end kits, gaskets, every single bearing/seal, plastics, fasteners, clutch cable, sprockets, chain, air filter, exhaust packing, carb kit, power valve, yada yada yada.

The bike then sat in the old shed for months, then we moved, then it sat here for a few more months

Well, I finally found the time to get this thing going. Popped the bearings in the freezer, and warmed up the shop. Yes, I keep ice cream out there. The house is a good walk away and sometimes you need to take a Breyer's break!

New cylinder...NICE

Completed top-end

At this point I went over the bike to check ALL bearings and such. Appears the PO changed all of these out before I picked it up. They were all good. Cleaned and greased. I'll save all of the new ones for down the road freshness!

Split the cases and took it all apart. Everything was good. Changed the main bearings along with the tranny shaft bearings. All others were good. Trans was in great shape so I was happy about that.

J-man67 · January 16, 2013

At this point I didn't really take any more pictures. I took a day off work on Friday. Once the kids and woman were gone, I got busy and FINALLY finished her up...kinda. THE VERY LAST piece to my puzzle was no-where to be found. I could not find the tranny fluid drain bolt. It was the first bolt I took out when I started dis-assembly back in April. Luckily I labeled and stored everything else OK. What a drag though. Got that far in a day and couldn't even start her up when completed. Oh well, the bolt is on order and I'll get her running by Saturday AM. I searched and searched for the measurement of that bolt and eventually found it, but it was after I ordered it. Figured might as well just wait for the correct part...its been this long already. Until then, she is just sitting in the garage with my tank awaiting the bolt, then fluids. I CANNOT WAIT. One reason b/c I NEED TO RIDE, the other, I am curious how my build went haha. Its my first time....

AND, complete!! Minus the drain bolt of course. I need to pick up some graphics as I am not 100% happy with the final look. I may even just go back to the OEM blue. Not sure yet. Don't really care at this point...like I said, I just want to RIP!!! Build went well. I had a couple hang-ups with the bearings and seals, but that was my own fault.

kstruckcountry · January 16, 2013

I'm interested to see it run, maybe a vid once its done?

J-man67 · January 16, 2013

You and me both buddy!! I want to make sure I re-built it ok. Make sure all my tolerances are good, timing, all that jazz. Transmission shifts great. Went through that on the stand. The tranny drain bolt is sitting outside my door at home. I have been tracking it like a hawk. I planned on a first start-up vid as well. By the time I get home and get it all set-up, it might be a little too late to start it up. My garage is a nice distance from my house, but I back up to a developement...don't want to disturb them at 9PM with a loud ass 2 stroke. I will have a start-up or FAIL video tomorrow evening.

KMGZ400 · January 16, 2013

nice bike.. i would go with white number plates and the rest of the bike blue. where do you ride in DE?

Babyhauler · January 16, 2013

You were riding too fast and blew it up!!! A stock bike just was not up to your skill level! Or you missed a shift.

Looking good now.

Weird how it slowly died like it leaned out, but had broken parts. I wish I had dirt bike again. Many years of fun. I guess I could run in the senior or super senior class. 49 years old now. I rode a CR250 for an afternoon last year. I can't believe I used to want them to go faster. Hard to hang on now.

What size is your shop?

I am moving in a few weeks and I am planning on a 30 x 40 x 10 shop with a lean to on the side. I got some good tips in the Garage section here.

Good luck with your YZ!

J-man67 · January 16, 2013

nice bike.. i would go with white number plates and the rest of the bike blue. where do you ride in DE?

Thanks man. Def needs white plates. Prob just swapping the blue back. Found the black kit for a decent price so just went for it. I used to ride at the DE Canal when I had a quad (KFX400) but went back with the bike and within 25 mins had the rangers on me. He said a 1000 ticket as I guess the land is now owned by the Army. They let me go as I didn't try to run. Glad I didnt as he had 2 other rangers on quads coming up the trail I was on. Strange since I was there a few weeks prior and I yanked a MD state trooper (off-duty) and his H2 out of a hole. I ride at Blue Diamond on rt 13, and in Oxford, PA on 100 acres. Guy I know has a circle track, TONs of trails, and a drag area. Its a blast when a bunch of friends head out. Where in PA are you?

You were riding too fast and blew it up!!! A stock bike just was not up to your skill level! Or you missed a shift.

Looking good now.

Weird how it slowly died like it leaned out, but had broken parts. I wish I had dirt bike again. Many years of fun. I guess I could run in the senior or super senior class. 49 years old now. I rode a CR250 for an afternoon last year. I can't believe I used to want them to go faster. Hard to hang on now.

What size is your shop?

I am moving in a few weeks and I am planning on a 30 x 40 x 10 shop with a lean to on the side. I got some good tips in the Garage section here.

Good luck with your YZ!

Yes, it was strange. I figured I just needed a new top-end. I think with the crank bearings bad, then the piece from the power valve breaking off, it all just added up into nothing good. Oh well, motor is COMPLETELY re-built so it'll be good for a while. I am 29 now, but been thinking about racing again. They do have a bunch of 30+ classes. We will see. For now, just having fun. HAHA, I know what you mean when you talk about the 250 2-stroke. It is tough to hold on sometimes!!

The garage...not 100% on the exact dimensions. I refer to it as a 2 1/2 car. It WILL be added too sooner or later. Funny how I went from a 8x6 storage shed to this and now want more space, haha. We have only been in this house for a few months, so the garage still has a long way to go. When it warms up again, I am going to powerwash and epoxy the floor, build a new bench the whole stretch of the side wall, insulate, and start tooling it. Also want to have my buddy do a concrete slab in front that wraps around to the right, and maybe around the back. I would like to make a little shelter for the air compressor in the back as well as store the trailer. I love it as is though, trust me!

kstruckcountry · January 17, 2013

It's nice to have the air compressor in a different room, so much quieter.

KMGZ400 · January 17, 2013

in near scranton during the week but i am originally from west chester pa, i ride around there on weekends sometimes. i have a few friends who go to blue diamond, i never wanted to go until i got a 450. yeah im not too far from oxford, i go to deleware to shop sometimes.

J-man67 · January 17, 2013

It's nice to have the air compressor in a different room, so much quieter.

Def is. When I was installing my lift, I used my dads 8 gallon in his garage. I wanted to shoot a bullet through my ears. 2 days of that thing was making me crazy haha. There is some roofing and siding left over. I am going to frame a little "closet" and run the hoses through the soffit. Then side and shingle it to blend and keep the compressor protected. Need to get 220 out there now though...could of sworn I saw a 220 outlet when I was looking at the place before purchase. Oh well, neighbor is an electrician. JACKPOT!

in near scranton during the week but i am originally from west chester pa, i ride around there on weekends sometimes. i have a few friends who go to blue diamond, i never wanted to go until i got a 450. yeah im not too far from oxford, i go to deleware to shop sometimes.

Cool, I have been through West Chester a bunch of times. Well, get that 450 out there!!! They do have a quad area. haha, everyone comes to DE to shop!! Christmas time there is more out-of-state tags then in-state. Its crazy.

KMGZ400 · January 17, 2013

Def is. When I was installing my lift, I used my dads 8 gallon in his garage. I wanted to shoot a bullet through my ears. 2 days of that thing was making me crazy haha. There is some roofing and siding left over. I am going to frame a little "closet" and run the hoses through the soffit. Then side and shingle it to blend and keep the compressor protected. Need to get 220 out there now though...could of sworn I saw a 220 outlet when I was looking at the place before purchase. Oh well, neighbor is an electrician. JACKPOT!

Cool, I have been through West Chester a bunch of times. Well, get that 450 out there!!! They do have a quad area. haha, everyone comes to DE to shop!! Christmas time there is more out-of-state tags then in-state. Its crazy.

yeah im planning on going in the spring. if you see a black LTR450 with a blue helmet, thats me.

yeah a lot of people go to delewere from out of state, and theres a lot of good stores right on 202 just past the border

J-man67 · January 17, 2013

yeah im planning on going in the spring. if you see a black LTR450 with a blue helmet, thats me.

yeah a lot of people go to delewere from out of state, and theres a lot of good stores right on 202 just past the border

Nice! I will keep a look-out. Look for my truck. I will be there a lot with my 4 y/o at the pee-wee track! I think he is looking forward to my bike being resurrected more then I am! I used to live in N. Wilmingon, off 202. TONS of awesome stores. Now I am in the sticks in Smyrna haha. Oh well!!

J-man67 · January 18, 2013

I'm interested to see it run, maybe a vid once its done?

kstruckcountry · January 18, 2013

Nice! I bet it felt good to have it start that well. When I've redone small engines it's awesome to get an easy start.

J-man67 · January 18, 2013

Yeah, I was def happy/surprised it started on the 2nd full kick. I did a few prime kicks before the vid, then 1 more before a real kick. Idled perfectly, after warm it was snappy as hell. The 400 acres out front dont stand a chance on Saturday!!