2010 CRF250R

Does anybody have any detailed instructions on putting in a new crankshaft in a '10 crf250r? I have my engine out but not sure how to put in the new crank. Please help!?ImageUploadedByThumper Talk1381472051.108470.jpg

The CRF250R engine is one of the easiest engines to disassemble and reassemble.

Crank replacement is about a 2.5hr job start to finish, once the engine is on the bench. Most of that time is spent cleaning and prepping gasket surfaces. 

 

If you've never done a crank before, you might get help from someone who knows how. And watch them.

 

But since you asked:

 

You will need left, right, and center case gaskets, cyl base, and head gaskets. 

 

0.drain all fluids

1.Remove engine from frame

2.Remove valve cover, cam cap, cam, head, cyl,piston

3.Remove right and left side engine covers, leave the water pump in place

4.Remove flywheel and cam chain

5.Remove oil pump gear, balance shaft, small gear retaining bolt,  from the drive end of the crank. leave the clutch in place

   (note the keyed index on the balance drive gear and crank drive gear).

6.Remove case screws

7.Lift the left side case from the right leaving the fully intact transmission and crank in the right. 

8.Remove the crank from the right side case half. If anything falls out (shift fork shafts, washers)  put it back in place now.

 

This is very simplified, and there are things to be aware of in each step.

I don't think you can &%$#@! up a Honda by reassembling parts in the wrong place. I think parts only fit where they belong.

The only special tools needed are a flywheel puller for a 10-13 CRF250R, or 09-14 CRF450R. the older ones are the wrong size.

You will also need a rag to jam between the drive gears to remove the flywheel nut and drive nut from the crank.

 

Go to youtube and look for videos. they're out there.

Edited by nesc103y

I don't think you can &%$#@! up a Honda by reassembling parts in the wrong place. I think parts only fit where they belong.

 

You definitely can.

Pay attention to the direction of the piston: "IN" means intake which is towards the back of the bike. Don't put it in backwards like some idiot did to my buddies bike.

Don't lose the alignment pins for the cylinder.

Be careful when removing/installing the head, small things like to fall off, like the exhaust valve shims, cam clips, head nuts, etc.

Make sure to use a torque wrench on the head bolts - 29 foot pounds, applied in an X pattern, work up slowly to it

Make sure to use a torque wrench on the cam cap bolts - 12 foot pounds, applied in an H pattern, work up slowly to it

Make sure to set the timing properly and double check it once you put the cam chain tensioner in, it is easy to misalign.

You don't need to use a pattern or step-up values on the cam bearing caps. Once the bolts are lightly snugged with the caps mounted and contacting their mating surfaces you're good to go with the torquing. There's nothing being "squished" and there's no "torque to yield" going on...

Edited by Eddie8v

*cough* I think i'll spend 30 extra seconds torquing it the way honda recommends.

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Edited by mudguy

12ft pounds seem like a lot for the cam caps. Is that whats called for in the manual?

 

 

I only use the torque wrench on the head bolts. And never had any problem.

RTFM

Lol, yeah 4, 8 then 12, that'll make a difference on divorced solid blocks of aluminum without a gasket. Whatever makes you feel better. The sharpest tools don't author those manuals and there's little Engineering to be desired...

Edited by Eddie8v

Does anybody have any detailed instructions on putting in a new crankshaft in a '10 crf250r? I have my engine out but not sure how to put in the new crank. Please help!?attachicon.gifImageUploadedByThumper Talk1381472051.108470.jpg

 

I strongly suggest you purchase the 2010 CRF250R OEM Service Manual. That will be the best money you can spend if you plan to do the job yourself, and especially if you plan to keep the bike.

 

It will save you lots of time, money, and headache. 

 

JL

12ft pounds seem like a lot for the cam caps. Is that whats called for in the manual?

I only use the torque wrench on the head bolts. And never had any problem.

I think 12lb-ft is what's called out in the SM, I run 14 on the big-lift / big-duration camshafts...

Edited by Eddie8v

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