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Old 04-25-2014, 08:02 PM   #1
OTMRR
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RIP Lorena..
 
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07 GSX-R750
06 CBR1000RR SF project.
TRX450r (500 hill shooter)
71 CB500
02 Ca Plated XR400r






OTM's CRF250R resurrection..

Yeh I know it's not a street bike but some people will find it interesting..

Picked this 05 CRF250r up cheap early last year, motor was apart, top end in a box along with a bunch of random parts.. The owner said it seized up but he didn't know why, started to take it apart, got a bit out his depth and stopped. He did it nicely with all parts in bags / labelled so that helped, just needed to know why it seized..

How it looked when I got it home (top end of motor / parts in blue box).



Fast forward over a year, and after I got a rid of some of my other projects.. decided it was time. I flipped a CRF450r recently and liked the way it rode so I started wondering what a decent 250R would be like..

Projects.. and the 450r I had for a few weeks..





So dragged it from the corner three weeks ago.. motor first to come out, find out what happened / what I needed.

Found my answer in the head, cooked cam, bucket seized into head, mushroomed valve stem. Basically a classic oil starved top end. Getting seats cut / guides replaced is approx $200.. for $250 I picked up a brand new head (with new seats/guides etc), it was the updated 08 head I got with the better port layout than earlier years so I was happy with that.

Old head.. see heat damage on Ex rocker. and bucket guides chewed up (had to knock stuck bucket out.. basically a trash head)





Motor torn apart, new crank, all new crank, tranny and balancer bearings. New seals, oil pump, piston, cam (HotCam Stage 2 to wake the little thing up a bit), new valves, springs, Ex V rocker/shaft, tensioner, cam chain.
Bumped the compression slightly by removing centre layer of HG.. should be around 0.8:1 bump which on these little motors is actually noticeable.





New head / valves / springs





Cam in, shimmed.



So whilst waiting for all my parts thought I'd clean it up a little.. got a little carried away, glad I did now because every nut/bolt/washer/part on the bike got taken off, inspected, put through part washer and cleaned up.





Carb sat with gas in it for who knows how long.. that's the brown goop by the AP nozzle which a to clean..(why you should clean gas out)




I was in the middle of rebuilding my mates motor (quad) for him kinda at the same time so he helped me get the big parts together after we'd sorted his bike out..



Coming together..





Together enough for a test ride.. New chain / sprockets, still waiting on some parts but nothing important..




Went to Cal City and broke in both motors together.. then went for a blast.. pretty happy with the way it runs.. !



Didn't really have trouble starting but on occasion it was more than 2-3 kicks which I'm pretty about so I modded the decomp shaft (a known fix, courtesy of Ron Hamp..the CRF guru) for less Ex V open duration when starting..

Decomp shaft before..



During..



After..



In situ..



New wheel bearings / brakes F+B. Some nice Maxxis Desert IT tires (best desert tire out there apparently), HD tubes in both. New Odi Cushion grips, and swapped out the haggard bar pad for a good one I had sat on my shelf. All cleaned up.. needs some work on suspension but that can be done in off season now..

Got a sweet little desert toy, all new internals.. actually the only original bearing left on bike are the stem bearings.

Finished this afternoon.. Off to Plaster City tomorrow to watch the Score 250 race.



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Old 04-25-2014, 08:09 PM   #2
KABIKANO
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Nice work!
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Old 04-25-2014, 08:46 PM   #3
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Cool The CR 500 two stroke motor would fit nicely where that limp CRF250r was . . .

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Nice work!
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Old 04-25-2014, 08:52 PM   #4
OTMRR
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RIP Lorena..
 
Join Date: May 2013
Location: Carlsbad, Ca
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Posts: 806

Experience: 10+ years

Bike(s):
07 GSX-R750
06 CBR1000RR SF project.
TRX450r (500 hill shooter)
71 CB500
02 Ca Plated XR400r






Lol.. too old for big 2 bangers fella.. I rode a KX500 10 years ago and shat myself..

One of Service Honda's new CR500's was for sale locally a few weeks ago..

Hey and less of the "limp" too.. it's pretty peppy for a little 'un.. All fresh with the comp bump and cam it comes close(ish) to the worn out 450 I had.

Last edited by OTMRR; 04-25-2014 at 08:56 PM.
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Old 04-25-2014, 09:16 PM   #5
Dlok750
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Stewart, you are the F*n man bro. I love your builds and your thorough explanations. You sir can build some pretty awesome . Wish I had some of your knowledge. I would like to assist you in some of your projects to learn and to see a finished project. I tend to start some and never quite see the end result. All in all you've do e some bad builds. Can't wait to see that Honda street fighter project come to life. Keep up that fine work!
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Old 04-25-2014, 09:28 PM   #6
OTMRR
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RIP Lorena..
 
Join Date: May 2013
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Posts: 806

Experience: 10+ years

Bike(s):
07 GSX-R750
06 CBR1000RR SF project.
TRX450r (500 hill shooter)
71 CB500
02 Ca Plated XR400r






Quote:
Originally Posted by Dlok750 View Post
Stewart, you are the F*n man bro. I love your builds and your thorough explanations. You sir can build some pretty awesome . Wish I had some of your knowledge. I would like to assist you in some of your projects to learn and to see a finished project. I tend to start some and never quite see the end result. All in all you've do e some bad builds. Can't wait to see that Honda street fighter project come to life. Keep up that fine work!
Thank you.

Your more than welcome to round anytime Dan.. doubt we'll get much done but it'll be a top laugh!

Got to finish / move my XR400 then the fighter project starts..
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