New to me 2003ish YZ250

[4xFord]

So I picked up this beat up old boy last weekend.
Stripped it all out this weekend and will be trying to build it into some sort of enduro machine.
Bought it as a non runner, opened the top to see the piston broke a piece off, which then promptly found its way into the bottom section and wedged in between the crank and the casing.
Stange enough I found quite a bit of metal in the gearbox as well.
Was told it is a 2004 but I believe it to be a 2002-2003 as the front forks are 46mm at the bottom end. From what I found on the net the 2004 should have a 48mm fork setup.
Steel frame, alu subframe. Doesn't look to bad until you start taking it apart.
Will need a front fork rebuild, linkage rebuild, wheel bearings front and back, new sprockets, chain, complete rebuild kit top and bottom including all the bearings and seals, new clutch, new water pump and some fresh, hopefully restyle to 2016ish, plastic kit.
It looks to be a weighted flywheel already.
Does someone have any info on how the stock gears should be? I want to change it to a WR gear set for enduro, I just need to make sure it doesn't already have it in.

Anyone have a website or shop in the Durban area that I can order spares at? I usually use Perry's but haven't seen the aftermarket stuff I want there.

Anyway, here are some pictures.


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[miks]

Nice project! I'm currently looking for a similar bike to build into a lightweight enduro machine.

The WR gearset is a different  3,4, 5 - search online for the parts fiche and compare to what you have once the motor is open.

Send me a message for plastics etc, I can help with aftermarket options.

[mulmi]

I am looking to. Want to try and build an enduro machine for my son.

One of those learn as you go projects


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[macker]

Startline in Pinetown/ New Germany area have a good amount of aftermarket parts. There website has a handy Catalogue which is pretty comprehensive.

There is also a current ad on the Facebook marketplace for WR/YZ spares - looks like they are in Pmb.

https://www.facebook.com/marketplace/item/545418646292248/?ref=search&referral_code=marketplace_search&referral_story_type=post&tracking=browse_serp%3Ab9b88a3c-4251-4c3c-b32f-280990f57ff6

[4xFord]

Nice project! I'm currently looking for a similar bike to build into a lightweight enduro machine.

The WR gearset is a different  3,4, 5 - search online for the parts fiche and compare to what you have once the motor is open.

Send me a message for plastics etc, I can help with aftermarket options.

Thanks Miks, I did just this and found i have the stock gearing. This specific bike has so many problems that need to be repaired/replaced I don't think I'll get to put WR gears in.
Thanks a lot, I'll pop you a PM for the plastics. I am looking at putting on a Polisport restyle kit at a later stage.

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[4xFord]

Startline in Pinetown/ New Germany area have a good amount of aftermarket parts. There website has a handy Catalogue which is pretty comprehensive.

There is also a current ad on the Facebook marketplace for WR/YZ spares - looks like they are in Pmb.

https://www.facebook.com/marketplace/item/545418646292248/?ref=search&referral_code=marketplace_search&referral_story_type=post&tracking=browse_serp%3Ab9b88a3c-4251-4c3c-b32f-280990f57ff6

Thank you Macker, I PMed the lady with the spares.
I visited Startline today and they do have some of the things I want to replace, will certainly get the stuff from them as they are a lot cheaper then the other bike shops.

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[4xFord]

I am looking to. Want to try and build an enduro machine for my son.

One of those learn as you go projects


Sent from my iPhone using Tapatalk

Some advice I'm sure you already know, try look for a Alu frame as they have the much sought after SSS Suspension from 2006 and up.
Other then that, I hope you find a better example then I did.
This bike needed basically everything replaced.
Some good news is the guy I'm using for the engineering work says he is able to save the casings with some Alu welding.
He is also rebuilding my crank with a new conrod kit that I ordered today, fixing the head and resleeving the barrel.

All in I ordered new:
Wossner conrod kit
Wossner piston in size A which is stock as far as I have read. (66.35mm)
New crank bearings and seals
Complete gasket set
Complete oil seal kit
New Reeds
Carb Rebuild Kit
Some new MSD radiators
All the other bearings in the gearbox/engine

What I still need now is the following:
Clutch basket and whatever the other parts inside are called?
I'm not sure if mine can still be filed down as it looks pretty worn.
New friction and steel plates.
The smaller Magnesium clutch cover as mine is cracked. (I'll try get it repaired, but I doubt it's possible)
New waterpump wheel, I broke mine when stripping
New radiator hoses

I'm also looking for a metal ignition cover.
I spoke with the guys at Perrys today and they said I should call HMW Engineering in PMB as they make a billet one from Alu.

When the engine is complete I'll start with the outside where I need:
Gear lever
Rear brake lever
Rebuild kit for the front and back brake master cylinders
Rebuild kit for the front and back calipers
New discs and pads
New wheel bearings front and back
New bearing for the swingarm and linkages
New bearings for the back shock
Rebuild the front forks, I've never done this before but I'll strip it and have a look.
New grips
I'll have a look at some nice levers as well
Polisport restyle kit

I'll then also check the triple clamp bearings to see if they need replacing, they probably do

I have a set of Cycra hand guards, I need to finish cleaning them up then I can fit them.
I'll also have a look at replacing the handlebars, I would like a set of fat bars if the budget allows.

The app is being difficult again and doesn't want me uploading fotos. I'll try again over the weekend.

Haven't done much but I cleaned the cases with the dremel as I wanted to see how it would look. Didn't come out half bad. Will finish is up after the engineering is done.

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[4xFord]

1 - top cleaned case vs bottom dirty one
2 - clutch basket, cover and waterpump I need
3 - wear on the clutch basket
4 - water pump
5 - magnesium clutch cover where the crack is

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[big oil]

 

[Bappas]

I have most of a WR gearbox for you! There was one gear broken can not remember witch one! I can also help with that dent in the exhaust!

[v0lstruis]

Looking great, look at the UFO plastics kits as well, I found them in some cases to be 20% cheaper than the Polisport. But yes FB marketplace is an awesome tool to find bike parts.

[mulmi]

I am looking to. Want to try and build an enduro machine for my son.

One of those learn as you go projects


Sent from my iPhone using Tapatalk

Some advice I'm sure you already know, try look for a Alu frame as they have the much sought after SSS Suspension from 2006 and up.
Other then that, I hope you find a better example then I did.
This bike needed basically everything replaced.
Some good news is the guy I'm using for the engineering work says he is able to save the casings with some Alu welding.
He is also rebuilding my crank with a new conrod kit that I ordered today, fixing the head and resleeving the barrel.

All in I ordered new:
Wossner conrod kit
Wossner piston in size A which is stock as far as I have read. (66.35mm)
New crank bearings and seals
Complete gasket set
Complete oil seal kit
New Reeds
Carb Rebuild Kit
Some new MSD radiators
All the other bearings in the gearbox/engine

What I still need now is the following:
Clutch basket and whatever the other parts inside are called?
I'm not sure if mine can still be filed down as it looks pretty worn.
New friction and steel plates.
The smaller Magnesium clutch cover as mine is cracked. (I'll try get it repaired, but I doubt it's possible)
New waterpump wheel, I broke mine when stripping
New radiator hoses

I'm also looking for a metal ignition cover.
I spoke with the guys at Perrys today and they said I should call HMW Engineering in PMB as they make a billet one from Alu.

When the engine is complete I'll start with the outside where I need:
Gear lever
Rear brake lever
Rebuild kit for the front and back brake master cylinders
Rebuild kit for the front and back calipers
New discs and pads
New wheel bearings front and back
New bearing for the swingarm and linkages
New bearings for the back shock
Rebuild the front forks, I've never done this before but I'll strip it and have a look.
New grips
I'll have a look at some nice levers as well
Polisport restyle kit

I'll then also check the triple clamp bearings to see if they need replacing, they probably do

I have a set of Cycra hand guards, I need to finish cleaning them up then I can fit them.
I'll also have a look at replacing the handlebars, I would like a set of fat bars if the budget allows.

The app is being difficult again and doesn't want me uploading fotos. I'll try again over the weekend.

Haven't done much but I cleaned the cases with the dremel as I wanted to see how it would look. Didn't come out half bad. Will finish is up after the engineering is done.

Sent from my SM-G973F using Tapatalk

If my “first try” bike has this many issues I would not know where to start and where to run to.

Good luck


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[4xFord]

I have most of a WR gearbox for you! There was one gear broken can not remember witch one! I can also help with that dent in the exhaust!

Thanks Bappas, will PM you.

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[4xFord]

Looking great, look at the UFO plastics kits as well, I found them in some cases to be 20% cheaper than the Polisport. But yes FB marketplace is an awesome tool to find bike parts.

Thanks Volstruis, do you know how the fitment is? I watched a lot of videos where they say the Polisport has the best fitment, and I really want to restyle it to the newer model plastics.
Another benefit with the Polisport restyle kit is that you get a new shape air box as well.

Sent from my SM-G973F using Tapatalk

[4xFord]

I am looking to. Want to try and build an enduro machine for my son.

One of those learn as you go projects


Sent from my iPhone using Tapatalk

Some advice I'm sure you already know, try look for a Alu frame as they have the much sought after SSS Suspension from 2006 and up.
Other then that, I hope you find a better example then I did.
This bike needed basically everything replaced.
Some good news is the guy I'm using for the engineering work says he is able to save the casings with some Alu welding.
He is also rebuilding my crank with a new conrod kit that I ordered today, fixing the head and resleeving the barrel.

All in I ordered new:
Wossner conrod kit
Wossner piston in size A which is stock as far as I have read. (66.35mm)
New crank bearings and seals
Complete gasket set
Complete oil seal kit
New Reeds
Carb Rebuild Kit
Some new MSD radiators
All the other bearings in the gearbox/engine

What I still need now is the following:
Clutch basket and whatever the other parts inside are called?
I'm not sure if mine can still be filed down as it looks pretty worn.
New friction and steel plates.
The smaller Magnesium clutch cover as mine is cracked. (I'll try get it repaired, but I doubt it's possible)
New waterpump wheel, I broke mine when stripping
New radiator hoses

I'm also looking for a metal ignition cover.
I spoke with the guys at Perrys today and they said I should call HMW Engineering in PMB as they make a billet one from Alu.

When the engine is complete I'll start with the outside where I need:
Gear lever
Rear brake lever
Rebuild kit for the front and back brake master cylinders
Rebuild kit for the front and back calipers
New discs and pads
New wheel bearings front and back
New bearing for the swingarm and linkages
New bearings for the back shock
Rebuild the front forks, I've never done this before but I'll strip it and have a look.
New grips
I'll have a look at some nice levers as well
Polisport restyle kit

I'll then also check the triple clamp bearings to see if they need replacing, they probably do

I have a set of Cycra hand guards, I need to finish cleaning them up then I can fit them.
I'll also have a look at replacing the handlebars, I would like a set of fat bars if the budget allows.

The app is being difficult again and doesn't want me uploading fotos. I'll try again over the weekend.

Haven't done much but I cleaned the cases with the dremel as I wanted to see how it would look. Didn't come out half bad. Will finish is up after the engineering is done.

Sent from my SM-G973F using Tapatalk

If my “first try” bike has this many issues I would not know where to start and where to run to.

Good luck


Sent from my iPhone using Tapatalk

Thanks Mulmi, luckily this isn't my first rodeo haha.
My first rebuild attempt was a Honda CB400. I resprayed the frame and the tank and cleaned all the shiny bits up real nice. When it came to the engine I was completely lost but my dad assisted with the assembly. Then he realised the CDI was broken and we ended up selling it uncompleted. I'm still sad about that, will try and get one to rebuild at a later stage.

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[miks]

Looking great, look at the UFO plastics kits as well, I found them in some cases to be 20% cheaper than the Polisport. But yes FB marketplace is an awesome tool to find bike parts.

Thanks Volstruis, do you know how the fitment is? I watched a lot of videos where they say the Polisport has the best fitment, and I really want to restyle it to the newer model plastics.
Another benefit with the Polisport restyle kit is that you get a new shape air box as well.

Sent from my SM-G973F using Tapatalk

The Polisport kit is complete with the updated airbox. The UFO plastic bits and full kits are cheaper and fitment is good as well.
To make the bike feel like a 2021, Polisport is the way to go.

[4xFord]

Looking great, look at the UFO plastics kits as well, I found them in some cases to be 20% cheaper than the Polisport. But yes FB marketplace is an awesome tool to find bike parts.

Thanks Volstruis, do you know how the fitment is? I watched a lot of videos where they say the Polisport has the best fitment, and I really want to restyle it to the newer model plastics.
Another benefit with the Polisport restyle kit is that you get a new shape air box as well.

Sent from my SM-G973F using Tapatalk

The Polisport kit is complete with the updated airbox. The UFO plastic bits and full kits are cheaper and fitment is good as well.
To make the bike feel like a 2021, Polisport is the way to go.

That's the direction I'm leaning towards, thanks for the advice.

I picked up my piston this morning.
Nothing quite like getting new parts, it builds the anticipation and excitement to complete the process.
I'm still waiting for one shipment to arrive then I'll take all the necessary bits to the engineering shop so they can start the machining.

Here is a photo of the piston so long.

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[4xFord]

And the rest of the parts. Still need a few odds and ends but for now it's on to engineering. Will update again when I get the casings back and start building.
Super excited to see it coming together like this.

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[Bappas]

I have most of a WR gearbox for you! There was one gear broken can not remember witch one! I can also help with that dent in the exhaust!

Thanks Bappas, will PM you.

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Just wondering  did you find a box?

[4xFord]

I have most of a WR gearbox for you! There was one gear broken can not remember witch one! I can also help with that dent in the exhaust!

Thanks Bappas, will PM you.

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Just wondering  did you find a box?

Hi Bappas, no I haven't. I was thinking of running the stock gearing for now. Will PM you shortly

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