#projecttweaker 2002 YZ 250 build (update)

HardTaco
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HardTaco
Edited Date/Time 11/30/2016 9:39am
Short but sweet build. I switched back to two strokes in December after a frustrating affair with my 14 yz250f. I bought a new yz250x, that I absolutely love. After remembering how easy it was to work on two strokes I decided to find an old smoker and build it up as a practice bike. I found a cheap and BEAT 2002 yz250 to start with:






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HardTaco
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HardTaco 3/25/2016 7:42pm
3/25/2016 7:42pm
Its called #projecttweaker because I'd bet my small pay check the dude I bought it from has enjoyed some meth in his day......heres some tear down pics



The top end was thrashed !







HardTaco
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HardTaco 3/25/2016 7:49pm
3/25/2016 7:49pm Edited Date/Time 3/25/2016 7:52pm
The piston had at one time seized in the cylinder and smoked it, the crank was still within spec and felt good. Sent the cylinder off to powerseal and put in a rekluse core exp 2.0, CR style brake line and light speed fork guards
HardTaco
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HardTaco 3/25/2016 8:00pm
3/25/2016 8:00pm
Cylinder came back and threw a new wiseco in it because I have always preferred forged pistons



Bolted on a 2016 airbox, gnarly pipe and stock 2016 silencer becasue it makes smooth power





The Shop

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HardTaco
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HardTaco 3/25/2016 8:04pm
3/25/2016 8:04pm
The 2016 plastic was a fairly simple bolt on. Had to drill the front fender and get creative with the number plate but it was all a fairly smooth process. Also put on a 2004 yz rear master cylinder to get rid of the separate reservoir that came stock on the 2002


MX4EVR
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MX4EVR 3/25/2016 8:10pm
3/25/2016 8:10pm
Powdercoat that frame
HardTaco
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HardTaco 3/25/2016 8:10pm
3/25/2016 8:10pm
All buttoned up with some ufo frame guards, full 2016 plastic and an 18 inch rear wheel because I'm one of those weird woods racer guys .....the bike is surprisingly smooth compared to the 2006+ yz250's, but no where near as smooth as the 2016 yz250x I race. I'll probably end up putting on a 9 oz. Steahly flywheel weight and backing the timing off a hair to make it more like the 250x. My grand total for the bike is right around $2200 ....not too bad for a solid two stroke that looks fairly new!

HardTaco
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HardTaco 3/25/2016 8:15pm
3/25/2016 8:15pm
And here's a pic of my 2016 250x that brought back my love for two strokes


HardTaco
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HardTaco 3/25/2016 8:32pm
3/25/2016 8:32pm
Much more. I'm a bigger guy (200-205 lbs) and was wringing the tits off of my 250f......had even big bored it to a 270 but it still just wasnt enough for my weight running Vet A woods races. At the tight coastal races the 270f was enough but in the mountains and the more open races the 250x is the perfect amount of smoothness and power.
HardTaco
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HardTaco 3/26/2016 6:16am
3/26/2016 6:16am
I do, I barely ride woods for practice, mostly MX. The stock suspension on the 250x is gonna be a little soft for peakier jumps but will do find on GP style stuff.
DoctorJD
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DoctorJD 3/26/2016 7:13am
3/26/2016 7:13am
HardTaco, was the airbox/sideplate a clean fit, or did you have to do any mods?

BTW, I have an 02' as well, and yes, that thing has some super-smooth power. Of course, I have a 11oz flywheel (with a Factory Fatty and a Powercore II) so it rides almost like a four-stroke. Thinking of going down to a 9oz to give it a little more hit.
FLmxer
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FLmxer 3/26/2016 7:37am
3/26/2016 7:37am
Great job. I have an 02 yz250 with maybe 20 original hours. As soon as i get rid of a few other bikes in the way, i will get that bad boy going.
HardTaco
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HardTaco 3/26/2016 8:27am
3/26/2016 8:27am
The airbox/sideplate/rear fender and shrouds are direct bolt on. The front fender has to be drilled. I'll take some pics of what I did for the front number plate
EmDub425
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EmDub425 3/26/2016 10:09am
3/26/2016 10:09am
What pipe did you put on your new 250X? Did it make the power more similar to a regular YZ or is it still much smoother? I would assume most of the way they made that smooth power is done with the ignition timing, compression ratio, and porting.
HardTaco
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HardTaco 3/26/2016 1:07pm
3/26/2016 1:07pm
EmDub425 wrote:
What pipe did you put on your new 250X? Did it make the power more similar to a regular YZ or is it still much smoother...
What pipe did you put on your new 250X? Did it make the power more similar to a regular YZ or is it still much smoother? I would assume most of the way they made that smooth power is done with the ignition timing, compression ratio, and porting.
I put a gnarly on my 250x with the stock long silencer. Didnt really effect power. The only reason I switched is the gnarly is made of thicker metal so it doesn't dent as easy
captain.olives 3/26/2016 3:15pm
3/26/2016 3:15pm
Nice build, great minds think alike. Built my 02 as a woods bike. Senior C, so considerably slower and less skilled then yourself I am sure. Havent gotten to ride the X yet, hope to some time later this spring. Woiuld be very curious how your project compares to the X after you have added the flywheel weight and retarded the ignition.

Thats basically where I am at with my project, added the 11oz flywheel weight and backed the ignition timing 2 degrees. Only thing else I am considering until I ride the X is lowering the compression so I can run pump gas without worries. I know my bike is smoother than than some of my riding partners YZ's.... but dont know if it is X like yet (ie is there potential to make it even smoother.) It has made a huge improvement in my riding getting off the 450.

The input and of a experienced rider like yourself with both bikes would be huge for a lot of us guys chasing a smooth YZ woods ride.

lumpy790
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lumpy790 3/26/2016 3:25pm
3/26/2016 3:25pm Edited Date/Time 3/26/2016 3:27pm
2001 ...



From this to ....

Pit Row

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Slosh 112
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Slosh 112 3/26/2016 6:11pm
3/26/2016 6:11pm
How do you like those Pro Taper foot pegs? I bought a set and they wore down flat within a few months, got pretty cranky with them and threw them over my shoulder. Yours do the same ?
HardTaco
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HardTaco 3/26/2016 10:44pm
3/26/2016 10:44pm
captain.olives wrote:
Nice build, great minds think alike. Built my 02 as a woods bike. Senior C, so considerably slower and less skilled then yourself I am sure...
Nice build, great minds think alike. Built my 02 as a woods bike. Senior C, so considerably slower and less skilled then yourself I am sure. Havent gotten to ride the X yet, hope to some time later this spring. Woiuld be very curious how your project compares to the X after you have added the flywheel weight and retarded the ignition.

Thats basically where I am at with my project, added the 11oz flywheel weight and backed the ignition timing 2 degrees. Only thing else I am considering until I ride the X is lowering the compression so I can run pump gas without worries. I know my bike is smoother than than some of my riding partners YZ's.... but dont know if it is X like yet (ie is there potential to make it even smoother.) It has made a huge improvement in my riding getting off the 450.

The input and of a experienced rider like yourself with both bikes would be huge for a lot of us guys chasing a smooth YZ woods ride.

I got a chance to take the 2002 to a local MX track today. The suspension hasn't been touched yet so it was way soft for my weight, but never got SUPER out of shape surprisingly enough. As much as I hate to say it I think the steel frame 02 hooks up a little better on hard pack slick stuff compared to the newer aluminum frame stuff. The motor is actually smoother than I thought. Running non ethanol 93 with amsoil dominator at 44/50:1 with stock jetting and the newer needle (N3ew) it was crisp but didn't have the mid range punch of the newer YZ's (06+), and no pinging. I'll put on a 9oz flywheel weight and most likely just leave it alone. It honestly seems pretty close to the 250x now and should be almost identical with a flywheel weight. The biggest mistake I see woods guys make on YZ's is go up on the rear sprocket. Stock 14-50 is perfect for almost everything, and if you must change, go down to a 49 or 48 on the rear and thank me later. Second to that is running any type of shorty silencer, the Euro spec 2011 and newer stock YZ silencer seems to be about the best in my opinion for smooth predictable power. If I'm not mistaken the YZ's didn't become absolute rocket ships until 2006 when they got a bump in compression.....once I get the suspension done by total control I'll have a better idea of just how close I can get it.
HardTaco
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HardTaco 3/26/2016 10:46pm
3/26/2016 10:46pm
Slosh 112 wrote:
How do you like those Pro Taper foot pegs? I bought a set and they wore down flat within a few months, got pretty cranky with...
How do you like those Pro Taper foot pegs? I bought a set and they wore down flat within a few months, got pretty cranky with them and threw them over my shoulder. Yours do the same ?
They suck.....lol. I got them horse trading parts one time and ran them on my 250f for a while. They are nice and wide but do wear super fast. The springs that come with them are super weak also compared to the stockers. Once I wear them completely flat ill prolly try to find an OEM take off set from a newer YZ or run the IMS ones.
HardTaco
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HardTaco 3/26/2016 10:53pm
3/26/2016 10:53pm
And I almost forgot the biggest difference......HOLY SLICK SEAT BATMAN!!! Gripper seats have made me lazier than any other modern invention. I busted my gems on the gas cap the first turn I really charged in to today. I'll be finding a newer YZ seat that isn't smooth leather like the stock 02 is very soon.
Underground 3/27/2016 3:21pm
3/27/2016 3:21pm
Cool budget build that you are modifying to suit yourself. With the range of used year model stuff out there, you can really change the stock dynamics. Have you thought much about playing with swingarms also? Great change to see also from the masses of high dollar garage queens, that while sweet to look at, go against the whole "4 strokes are too expensive" theme IMO
HardTaco
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HardTaco 3/27/2016 3:30pm
3/27/2016 3:30pm
I agree underground. I like riding bikes more than I like polishing parts.......I love trick bikes and my 2016 has all kinds of bling on it but I still put 120-140 hours a year on a bike so none of my stuff will stay pretty for long unfortunately. I have thought about a newer swingarm so I'm definitely keeping an eye out for an 08 or newer 250 smoker swingarm for the right price. The four stroke swingarm swap seems cool but Idk what all is involved with it
Underground 3/27/2016 8:19pm
3/27/2016 8:19pm
HardTaco wrote:
I agree underground. I like riding bikes more than I like polishing parts.......I love trick bikes and my 2016 has all kinds of bling on it...
I agree underground. I like riding bikes more than I like polishing parts.......I love trick bikes and my 2016 has all kinds of bling on it but I still put 120-140 hours a year on a bike so none of my stuff will stay pretty for long unfortunately. I have thought about a newer swingarm so I'm definitely keeping an eye out for an 08 or newer 250 smoker swingarm for the right price. The four stroke swingarm swap seems cool but Idk what all is involved with it
Not up on the swingarm swap logistics either as I've never done it but I'm sure someone will weigh in with some legit info. If you can pick the bits up for a good price, and you have the time, you can find out what works and what doesn't from your own seat time. One of the later swingarms and Ti springs (although I'm thinking your too heavy for the STD Yamahas) would drop some unsprung weight real cheap too.
I was trying to pick up an 02-04 YZ before Xmas after finishing a 93 CR restore to do similar but none came up in the right condition/price ratio for me. Now that window of available cash has moved on I'll just have to wait a bit.
FLmxer
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FLmxer 3/27/2016 8:23pm
3/27/2016 8:23pm
Thanks for sharing. Good times.
captain.olives 3/28/2016 10:53am
3/28/2016 10:53am
captain.olives wrote:
Nice build, great minds think alike. Built my 02 as a woods bike. Senior C, so considerably slower and less skilled then yourself I am sure...
Nice build, great minds think alike. Built my 02 as a woods bike. Senior C, so considerably slower and less skilled then yourself I am sure. Havent gotten to ride the X yet, hope to some time later this spring. Woiuld be very curious how your project compares to the X after you have added the flywheel weight and retarded the ignition.

Thats basically where I am at with my project, added the 11oz flywheel weight and backed the ignition timing 2 degrees. Only thing else I am considering until I ride the X is lowering the compression so I can run pump gas without worries. I know my bike is smoother than than some of my riding partners YZ's.... but dont know if it is X like yet (ie is there potential to make it even smoother.) It has made a huge improvement in my riding getting off the 450.

The input and of a experienced rider like yourself with both bikes would be huge for a lot of us guys chasing a smooth YZ woods ride.

HardTaco wrote:
I got a chance to take the 2002 to a local MX track today. The suspension hasn't been touched yet so it was way soft for...
I got a chance to take the 2002 to a local MX track today. The suspension hasn't been touched yet so it was way soft for my weight, but never got SUPER out of shape surprisingly enough. As much as I hate to say it I think the steel frame 02 hooks up a little better on hard pack slick stuff compared to the newer aluminum frame stuff. The motor is actually smoother than I thought. Running non ethanol 93 with amsoil dominator at 44/50:1 with stock jetting and the newer needle (N3ew) it was crisp but didn't have the mid range punch of the newer YZ's (06+), and no pinging. I'll put on a 9oz flywheel weight and most likely just leave it alone. It honestly seems pretty close to the 250x now and should be almost identical with a flywheel weight. The biggest mistake I see woods guys make on YZ's is go up on the rear sprocket. Stock 14-50 is perfect for almost everything, and if you must change, go down to a 49 or 48 on the rear and thank me later. Second to that is running any type of shorty silencer, the Euro spec 2011 and newer stock YZ silencer seems to be about the best in my opinion for smooth predictable power. If I'm not mistaken the YZ's didn't become absolute rocket ships until 2006 when they got a bump in compression.....once I get the suspension done by total control I'll have a better idea of just how close I can get it.
Thanks for the input! Running the stock pipe and FMF TC2 with sparky now. Out of curiosity, why do you suggest the higher gearing? I've run lower (ie larger rear) and found it spun up more and actually made it tougher to control/find traction for my skill level in slow technical sections (rocks/roots/steep). Use a G2 to help me control the throttle now and 50 rear. The G2 masks my less than precise throttle control when getting bounced around in the slow technical stuff.

Does the higher gearing you are running allow it to hook up better?

Thanks again for sharing your experience. Love these more realistic and useful builds than the mega bucks ones.
HardTaco
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HardTaco 3/28/2016 11:00am
3/28/2016 11:00am
captain.olives wrote:
Nice build, great minds think alike. Built my 02 as a woods bike. Senior C, so considerably slower and less skilled then yourself I am sure...
Nice build, great minds think alike. Built my 02 as a woods bike. Senior C, so considerably slower and less skilled then yourself I am sure. Havent gotten to ride the X yet, hope to some time later this spring. Woiuld be very curious how your project compares to the X after you have added the flywheel weight and retarded the ignition.

Thats basically where I am at with my project, added the 11oz flywheel weight and backed the ignition timing 2 degrees. Only thing else I am considering until I ride the X is lowering the compression so I can run pump gas without worries. I know my bike is smoother than than some of my riding partners YZ's.... but dont know if it is X like yet (ie is there potential to make it even smoother.) It has made a huge improvement in my riding getting off the 450.

The input and of a experienced rider like yourself with both bikes would be huge for a lot of us guys chasing a smooth YZ woods ride.

HardTaco wrote:
I got a chance to take the 2002 to a local MX track today. The suspension hasn't been touched yet so it was way soft for...
I got a chance to take the 2002 to a local MX track today. The suspension hasn't been touched yet so it was way soft for my weight, but never got SUPER out of shape surprisingly enough. As much as I hate to say it I think the steel frame 02 hooks up a little better on hard pack slick stuff compared to the newer aluminum frame stuff. The motor is actually smoother than I thought. Running non ethanol 93 with amsoil dominator at 44/50:1 with stock jetting and the newer needle (N3ew) it was crisp but didn't have the mid range punch of the newer YZ's (06+), and no pinging. I'll put on a 9oz flywheel weight and most likely just leave it alone. It honestly seems pretty close to the 250x now and should be almost identical with a flywheel weight. The biggest mistake I see woods guys make on YZ's is go up on the rear sprocket. Stock 14-50 is perfect for almost everything, and if you must change, go down to a 49 or 48 on the rear and thank me later. Second to that is running any type of shorty silencer, the Euro spec 2011 and newer stock YZ silencer seems to be about the best in my opinion for smooth predictable power. If I'm not mistaken the YZ's didn't become absolute rocket ships until 2006 when they got a bump in compression.....once I get the suspension done by total control I'll have a better idea of just how close I can get it.
captain.olives wrote:
Thanks for the input! Running the stock pipe and FMF TC2 with sparky now. Out of curiosity, why do you suggest the higher gearing? I've run...
Thanks for the input! Running the stock pipe and FMF TC2 with sparky now. Out of curiosity, why do you suggest the higher gearing? I've run lower (ie larger rear) and found it spun up more and actually made it tougher to control/find traction for my skill level in slow technical sections (rocks/roots/steep). Use a G2 to help me control the throttle now and 50 rear. The G2 masks my less than precise throttle control when getting bounced around in the slow technical stuff.

Does the higher gearing you are running allow it to hook up better?

Thanks again for sharing your experience. Love these more realistic and useful builds than the mega bucks ones.
That's exactly why. Back before my 250f I had a regular aluminum frame YZ smoker and ran a 14-49 occasionally, usually the 14-50. Made each gear a little longer and helped with taming the hit. A core exp rekluse also works wonders on these bikes. If you do go down to a 48-49 rear a gnarly pipe will bring some of the bottom end back without making it super snappy. I ran 14-52 once and despised it, bike was all over the place and would get you in a lot of trouble without perfect throttle control.
captain.olives 3/28/2016 11:31am
3/28/2016 11:31am
Thanks, good to know my impressions weren't off then. Easy to second guess yourself and good to have a more experienced rider confirm it. We have had a more than a few heated arguments around the campfire on gearing.

Agree on the EXP, ran them in my fourstrokes before this YZ. I have a new EXP and clutch pack sitting on my bench in the shop that I have been waiting to install. Just waiting to burn the installed clutch out before installing the new parts. Dont know if its urban myth or not, but folks have told me its better to install an EXP with new parts and not used ones. True?

I'm cheap and feel wasteful to toss the working clutch pack. Then again, its been 18 months and still havent been able to wear out the installed clutch.

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