2003 CR250R suggestions on maintance

Related:
Create New Tag

5/18/2018 5:06 PM

Hi this is my first post. I got a 2003 CR250 when I was 14 the year it came out. I rode the bike constantly for 4 years did some Deseret races and motocross races. Long story short I have only riden the bike once in the last 10 years. The suspension has leaking forks and the rear shock bottoms out and on every bump. I live in New York and will be going back to Arizona where I grew and want to ride.

I am planning on putting new fuilds, tires, chain/sprocket topend and maybe a bottom.

I loved the stock suspension when I was 14 lol, but I am probably 30 pounds heavier. I am 220 pounds. What should I do about the suspension? I don’t want to send it out or anything like that. What should I order? Also any other suggestions would be appreciated.

Here is a pic I put new plastic on the last time I rode Photo Photo

|

5/19/2018 4:13 AM

Are you mechanically inclined? Factory service manual will help you through suspension fluid and seal changes, but you will need basic skills and tooling. The Cr eats upper shock spherical bearings , after 4 riding years it probably has some play, as likely do the shock linkage bearings. Yes you’ll need heavier springs. Race tech website has spring rate calculator. A Keihin or lectron are good replacement for the mikuni on this model. Pv cables stretch and need frequent inspection for adjustment. The shrouds rub the frame and wear grooves into the frame. Some clear protective tape can help in these areas. Mountain bike shops always have clear frame protector tape in stock, it only takes a few small pieces. The stock airboot airbox connection lets in dirt, get creative with the sealant, or do one of the many airbox mods , lots of info out there on ideas to seal it up better. Remind me if your bottom end has the tin crank covers, cr owners opt to install newer non tin cranks on rebuild just verify interchangeability first. It’s a great bike with a little help here and there.

|

5/19/2018 4:53 AM

X2 on the springs and go with the lectron carb.

|

5/19/2018 5:12 AM

Mx746 wrote:

Are you mechanically inclined? Factory service manual will help you through suspension fluid and seal changes, but you will need basic skills and tooling. The Cr eats upper shock spherical bearings , after 4 riding years it probably has some play, as likely do the shock linkage bearings. Yes you’ll need heavier springs. Race tech website has spring rate calculator. A Keihin or lectron are good replacement for the mikuni on this model. Pv cables stretch and need frequent inspection for adjustment. The shrouds rub the frame and wear grooves into the frame. Some clear protective tape can help in these areas. Mountain bike shops always have clear frame protector tape in stock, it only takes a few small pieces. The stock airboot airbox connection lets in dirt, get creative with the sealant, or do one of the many airbox mods , lots of info out there on ideas to seal it up better. Remind me if your bottom end has the tin crank covers, cr owners opt to install newer non tin cranks on rebuild just verify interchangeability first. It’s a great bike with a little help here and there.

Thanks for the reply! I will not be doing any of the work, because I have zero ability or knowledge. My friends shop who did all the work on it previously will do it. All I have to do is buy the parts. I am just doing some research on my own because its fun, and I want to learn more. I’ll check out race tech. I also heard about the air box and will look into that as well. I’ll look into the bearings too for the rear shock, and a solution for frame wear. Not sure about the crank. I have had a number or rebuilds, but not sure what was used. I have read lately people complaining about the carb. The only time i can remember having an issue is when we would go to a different city to ride (elevation). It would ruin rich, but my guys would just change the jets and it ran fine. Hearing that the carb is fussy I’ll look out for it and see about switching.


I have seen the wrench rabbit rebuild top and bottom kit. Have you had any experience with them? Looks like a great deal, but I have read it may lack quality. I remember using weisco back when I used to ride. Reading up lately and people have been drilling the piston because of the exhaust port, or somthing like that.

What brand would you rebuild with? Also what about the clucth. last time I rode 5 years ago it seemed fine, but I’m not sure what has ever been done to it, so probably time for some maintenance of some sort.


Thanks for all the advice

|

5/20/2018 6:21 AM
Edited Date/Time: 5/20/2018 6:22 AM

No need to swap the mikuni if its working for you, but there are many satisfied owners who did the keihin swap, as its just more stable overall with temperature and elevation. Its one of those mods that can go on the back burner or until you're fed up with swapping brass between motos. I have the Wrench Rabbit kit in a 90's CR, no problems yet, have run hot rods in the past with good results. I've usually used OEM cranks on my bikes for rebuilds, so Im curious to see how the WR kit holds up. Ill post a long haul thread down the road when I have some hours on her. You're correct about the piston holes, the instructions with the new piston will list the size and spacing, they allow more lubrication to the thin exhaust bridge in the cylinder. The CR is sensitive to fork height, if you raise the forks even a touch too high in the clamps, you risk some nasty headshake, the turning is fine with forks at normal height.
I always used Wiseco, I prefer forged. (Just let the bike warm up more slowly as forged expands quicker on start up.)
The clutch is good in this bike, I replaced the stocker with hinson after a few years, just check the basket and its bearing/bushing to make sure its free of grooves and play. I did burn up a lot of clutch plates, as Im a clutch abuser. Oem plates lasted longest, but I ran many Barnett kits with good results, I wasn't happy with one of the EBC kits, but who knows, probably was more my fault than the clutch kit.
If you plan to mx it the stock 48 is awful for normal mx tracks. If your riding is in wide open areas its fine. For mx it needs a 50, or 51 for really tight tracks. This also helps the soft bottom end power the CR is known for. This bike is great in the mid range, and not too shabby up top either. I currently have a YZ but I plan on putting an 02-07 back in the garage at some point, its a great bike.

|

5/20/2018 7:51 AM

Great bike. I still own mine after 15 yrs. since I haven't found a better 250 2t replacement. Re-grease all the pivot points & replace the tires as they probably have dry rot from sitting. I've been running wossner pistons for a few yrs. with great results. https://wossnerpistons.com/products/8066
On the crank I'd only suggest running oem as well as all the gaskets for the engine rebuild. As mentioned the 13/50 gear ratio seems to be the sweet spot for the 02-04 stock engines. Honda went to a 13/48 combo on the 02-03 models after using a 13/50 for many years on prior models.
Agree about holding off on the Keihin carb swap as it's not really a must have in my experience. I tested with a 2000 38mm Keihin PWK A/S about 10 yrs. ago & ended up going back to the TMX mikuni.

|

Speak softly and carry a big stick.

5/20/2018 4:27 PM

Mx746 wrote:

No need to swap the mikuni if its working for you, but there are many satisfied owners who did the keihin swap, as its just more stable overall with temperature and elevation. Its one of those mods that can go on the back burner or until you're fed up with swapping brass between motos. I have the Wrench Rabbit kit in a 90's CR, no problems yet, have run hot rods in the past with good results. I've usually used OEM cranks on my bikes for rebuilds, so Im curious to see how the WR kit holds up. Ill post a long haul thread down the road when I have some hours on her. You're correct about the piston holes, the instructions with the new piston will list the size and spacing, they allow more lubrication to the thin exhaust bridge in the cylinder. The CR is sensitive to fork height, if you raise the forks even a touch too high in the clamps, you risk some nasty headshake, the turning is fine with forks at normal height.
I always used Wiseco, I prefer forged. (Just let the bike warm up more slowly as forged expands quicker on start up.)
The clutch is good in this bike, I replaced the stocker with hinson after a few years, just check the basket and its bearing/bushing to make sure its free of grooves and play. I did burn up a lot of clutch plates, as Im a clutch abuser. Oem plates lasted longest, but I ran many Barnett kits with good results, I wasn't happy with one of the EBC kits, but who knows, probably was more my fault than the clutch kit.
If you plan to mx it the stock 48 is awful for normal mx tracks. If your riding is in wide open areas its fine. For mx it needs a 50, or 51 for really tight tracks. This also helps the soft bottom end power the CR is known for. This bike is great in the mid range, and not too shabby up top either. I currently have a YZ but I plan on putting an 02-07 back in the garage at some point, its a great bike.

Yea I’ll probably hold off on the carb for now. I will only be home for a week to ride, so I’ll just stick to the engine and suspension. I’ll do either the wrench rabbit or Oem. I looked into race tech like you suggested. I am thinking I will get the fork spring and pivot works fork rebuild kit which come with seals washers ect.. for the rear I still need to do more research, but I think I could do the shock spring from race tech, and again the pivot works rear shock rebuild hit. Pivot works also has a linkage bearing kit.

Depending how bad of shape the sprocket is on the bike I’ll just keep what ever one is on there unless its really worn. I remember using both larger and smaller depending on riding type I was doing. I will only be able to ride it for a few days while home for a family reunion, so won’t be doing mx. If needed I’ll put a 48 given I will only be doing trail type riding.


I’ll have my friend/ mechanic look into the clutch and go from there.


|

5/20/2018 4:39 PM

H4L wrote:

Great bike. I still own mine after 15 yrs. since I haven't found a better 250 2t replacement. Re-grease all the pivot points & replace the tires as they probably have dry rot from sitting. I've been running wossner pistons for a few yrs. with great results. https://wossnerpistons.com/products/8066
On the crank I'd only suggest running oem as well as all the gaskets for the engine rebuild. As mentioned the 13/50 gear ratio seems to be the sweet spot for the 02-04 stock engines. Honda went to a 13/48 combo on the 02-03 models after using a 13/50 for many years on prior models.
Agree about holding off on the Keihin carb swap as it's not really a must have in my experience. I tested with a 2000 38mm Keihin PWK A/S about 10 yrs. ago & ended up going back to the TMX mikuni.

I haven’t riden to many bikes, but I loved my 03. I started off on a used 97 Cr80 and than went to my brothers 1991 yz125. That bike was a bit of mess,but it ran. My 03 was my first and only new bike. Super dependable and it was new, so I was happy.

I’ll check out the piston recommendation. I don’t really have a preference.

|