Jump to content

Another '02 CR250 rebuild *PIC HEAVY*

Recommended Posts

Hello there!  Long time lurker, first post.  Anywhew, I picked up this bike about 3 years ago, and I've since then pout own about 20 hours.  She had about 225 PSIG on the compression tester when I first picked her up.  Lately I noticed her power lacking; time for the rebuild.  So hopefully I can figure out this photo posting deal cause there's some good photos: 20170306_150246_resized.jpg

Cylinder head removed, cylinder exhaust bridge not looking too great.

20170306_155224_resized.jpg
Nice gouge in the cylinder wall, I am presuming from the huge chuck of reed petal that broke off and got sucked into the cylinder.

 

20170307_150252_resized.jpg

Naked!

20170312_162945_resized.jpg

Clutch basket removed, main drive shaft bearing was shot, A LOT of movement!  

20170312_171142_resized.jpg

Pesky little springs!

20170312_173037_resized.jpg

Left side removal.  Having the right tools makes things a lot easier.

20170312_175426_resized.jpg

I'm wondering if this could be the original crank.  If you look at that clutch basket you can see those notches!  She done!

20170312_175542_resized.jpg

Can't forget this o-ring.

20170313_130304_resized.jpg

This tool......ROCKS!

20170314_115901_resized.jpg20170314_115901_resized.jpg

New bearings going in.

20170314_115912_resized.jpg

Tranny out.  I used the rag to hold everything together; no huge zip-tie available.  Worked great.  Of course that all went out the door during reassembly.

20170314_173904_resized.jpg

When you live in Michigan (AKA Ice Planet Hoth), you don't need dry ice, just leave your bearings outside overnight in the crappy cold weather!

20170315_154042_resized (1).jpgBottom end getting buttoned up with a new 2005 OEM crank =)

20170316_090420_resized.jpg

New studs going into the new (if my wife new how much....) cylinder.  The old cylinder will ultimately be sent off for some porting work and a re-plate.

More pics to follow!  I am waiting on a few more parts such as a clutch basket and reeds.  She should be back together in the next couple of weeks.  

Thanks for checking out my first huge post!  BRAAAAAAAAP!  

20170315_154042_resized.jpg

20170306_150545_resized.jpg

20170306_155216_resized.jpg

20170307_150359_resized.jpg

20170311_072534_resized.jpg

20170312_163000_resized.jpg

  • Like 3

Share this post


Link to post
Share on other sites

Not this round.  I did however use a base gasket from the '05-07 motor.  I read mixed reviews about the thinner base gasket though.  We'll see how it goes.

  • Like 1

Share this post


Link to post
Share on other sites

Is one of your reed stoppers bent? I pulled my reeds out last week and one was bent. Got any idea how that could happen?IMG_0329.PNGIMG_0328.PNGalso do you think this could be the reason I'm running rich?

Share this post


Link to post
Share on other sites

Here's what my Reed cage looks like:
1490213465503.jpeg

As far as the bend, who knows? I'm sure the worn reed petal is contributing to your rich mixture. Check your packing. Also, when's the last time you re-built your carb?

Share this post


Link to post
Share on other sites
Here's what my Reed cage looks like:
1490213465503.jpeg

As far as the bend, who knows? I'm sure the worn reed petal is contributing to your rich mixture. Check your packing. Also, when's the last time you re-built your carb?

I haven't re-built my carb in 40hrs but I have rejetted it to my area as the manual says

Share this post


Link to post
Share on other sites

I haven't re-built my carb in 40hrs but I have rejetted it to my area as the manual says

I suggest replacing the reeds and and the cage. Then get some fresh plugs and do a chop test to see where your jetting is. Go from there. How's your right side crank seal?

Share this post


Link to post
Share on other sites
FYI I stumbled upon a whole used Reed cage assembly on ebay for around 30 bucks.

There's nothing wrong with the cage just the stoppers
  • Like 2

Share this post


Link to post
Share on other sites
7 hours ago, duncdivedeep said:

Not this round.  I did however use a base gasket from the '05-07 motor.  I read mixed reviews about the thinner base gasket though.  We'll see how it goes.

If you send the head out to get fixed (RB Designs) use the stock 02 base gasket. 

  • Like 2

Share this post


Link to post
Share on other sites
8 hours ago, Keith72 said:

If you send the head out to get fixed (RB Designs) use the stock 02 base gasket. 

Thanks for the recommendation Keith!  I have plans for the old cylinder...hehehehe.  Thats why I love thumper talk, so much collective knowledge and experience!

7 hours ago, frdbtr said:

Nice work.  I love these build threads. 

Thank you!  I'll post up more photos as I continue with the re-build.

Share this post


Link to post
Share on other sites
On ‎3‎/‎22‎/‎2017 at 0:17 PM, duncdivedeep said:

Not this round.  I did however use a base gasket from the '05-07 motor.  I read mixed reviews about the thinner base gasket though.  We'll see how it goes.

I currently run the 07 base gasket. you should notice a slight power gain at low rpm. I put calipers on both gaskets 02 and the 07.... The 07 gasket was .012 thinner. Nice work on the engine.... Your doing rite. Don't forget to put a little dab of yama/Honda bond under the metal base gasket where the cases meet

Edited by mxsteve1968
  • Like 2

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×