Another '02 CR250 rebuild *PIC HEAVY*

[duncdivedeep]

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: 

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

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.

 

Naked!

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

Pesky little springs!

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

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

Can't forget this o-ring.

This tool......ROCKS!

New bearings going in.

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.

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!

Bottom end getting buttoned up with a new 2005 OEM crank =)

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!  

[Piney Woods]

Fix the squish?

[duncdivedeep]

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.

[duncdivedeep]

Here's the fubar reed petal which I think is the culprit for the gouge in the cylinder.

[Egdt]

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?also do you think this could be the reason I'm running rich?

[duncdivedeep]

Here's what my Reed cage looks like:


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?

[Egdt]

Here's what my Reed cage looks like:


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

[duncdivedeep]

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?

[Egdt]

Crank seal is new. I purchased some boyesen dual stager reeds and reed stoppers. Why should I replace the cage?

[duncdivedeep]

I would replace it, but I'm OCD like that. If the tweaked cage isn't affecting performance, then let her rip!

[duncdivedeep]

FYI I stumbled upon a whole used Reed cage assembly on ebay for around 30 bucks.

[duncdivedeep]

Rebuild complete for theTMX. Someday I'll get a Keihn, but I'm on a budget and Daddy needs a new clutch basket!

[Egdt]

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

[Keith72]

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. 

[frdbtr]

Nice work.  I love these build threads. 

[duncdivedeep]

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.

[Piney Woods]

Suspension?

[duncdivedeep]

4 hours ago, YHGEORGE said:

Suspension?

I have new springs for my weight and fresh oil.  Just gotta do the work.

[mxsteve1968]

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 March 23, 2017 by mxsteve1968

[duncdivedeep]

New clutch basket and reeds on order, hopefully they should be here tomorrow.
Meanwhile..........