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cr250 bottom end rebuild/ crank shaft issue?

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I recently rebuilt the bottom end of my cr. New main bearings seals and crank

after i but the crank cases back together. And tightened down the bolts to spec

The cranks spins rough. I almost have to turn it by hand to get it to rotate.

it spins smoothly but its just feels like somthing tight

should it spin super smooth or tought to turn over because its brand new???

Help i dont have much resorce

thanks

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and more importantly, are you sure when you put the case halves together that you did not disturb any of the thrust washers on the transmission main shaft, or counter shaft? That seems to be a common problem. The washers must be installed in a specific orientation, and in a specific order. If you did not remove the transmission, or any of it's components, then disregard my post. There are a lot of posts where people have had the same issue as you and it turns out they put the thrust washers back in incorrectly.

 

When you pulled the crank into the case halves did it feel like the case halves did not want to go together all the way? Was there a gap between case halves that only closed up when you tightened the bolts?

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The bearing were in flush and went in no problem.

When i installed the crank shaft it wrnt insmooth the case halves went together like bitter and no i didnt tighten up a gap with the bolts

Could ot be a seal thats pushed in to far on the main crank bearing?

Im not a complete idiot haha

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Something wrong.

 

Sounds like thrust washers - I'd pull it back apart and check everything.

 

What crank did you use? What bearings?

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Weiseco bearings and crank. The thrust washers where in the correct spot. I atleast know they are in there

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The transmission is correctly istalled and is in perfect working condition. Shifts fins ans spins freely

it cant be the trust washers

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You talk about the crank seals... They must be pressed in exactly 1mm on one side and 2mm on the other. The countershaft seal also gets pressed in 1 or 2mm. If you go to far it restricts the lubrication channels, and oil won't get to the bearings. As far as spinning smoothly there should be resistance from the transmission but it should be smooth and quiet. I hate saying it, but if it is not smooth and quiet, I would disassemble and check with the transmission missing for smooth operation. Then add the transmission and spin it with the cases still spilt and make sure the transmission spins smooth. Also if you did disassembled the transmission there are two gears that look the same one is just a hair thicker and that can cause issues. I believe the issue is with the cases not closing properly though.

Good luck,

Chris

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You talk about the crank seals... They must be pressed in exactly 1mm on one side and 2mm on the other. The countershaft seal also gets pressed in 1 or 2mm. If you go to far it restricts the lubrication channels, and oil won't get to the bearings. As far as spinning smoothly there should be resistance from the transmission but it should be smooth and quiet. I hate saying it, but if it is not smooth and quiet, I would disassemble and check with the transmission missing for smooth operation. Then add the transmission and spin it with the cases still spilt and make sure the transmission spins smooth. Also if you did disassembled the transmission there are two gears that look the same one is just a hair thicker and that can cause issues. I believe the issue is with the cases not closing properly though.

Good luck,

Chris

i agree chris. So are you saying i should put oil in it first?

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i agree chris. So are you saying i should put oil in it first?[/quote

Everythings smooth but the crank. The thrust washers are in the right place and not mixed up or anything i even followed the ware marks on it. I think i pressed i. The left side crank seal to far. Possible??

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I'm a little lost on the oil part... The oil that lubricates the crank bearings is the oil you mix into the gasoline. What is the state of your engine right now? Just the bottom end assembled? Or the whole engine? If your positive the transmission is assembled correctly and you could shift the gears correctly with the shifter then you should be fine. Also when you look at the crank make sure it is centered in between the cases. I used a feeler gauge to get the crank perfectly centered. I don't think the seals being pushed in to far would create to much resistance unless you really pounded them into the crank. But I do think it is very important to get the three seals in at the proper distance. I don't recall the measurements, this is just a guess. I think the right seal is pressed in at 1mm below the lip, and the countershaft seal, gets pushed in at 1mm below the lip. Then the left side crank seal is pushed in at 2mm below the lip. This is for a 92-01 cr250. If yours is another year look it up in the manual or online. In fact still look up the pressed in limits if your bike is 92-01. I could be wrong on which seals get pushed into what. I used a piece of pipe coupling that was the size as my seal and then put that on my crank installer and tighten my crank (which pushed my seal inward) and I was able to push the crank seal in at a controlled rate to get it exactly.

Good luck,

Chris

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Weiseco bearings and crank. The thrust washers where in the correct spot. I atleast know they are in there

 

There's your problem. The Wiseco crank and bearings are junk. 

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Ok im looking at my crank from the top its just the bottom end assembled. The crank does not look evenly spaced. What can i do about that? The transmission is great i cam shift threw all gears properly and smoothly

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So use a feeler gage record the space on left and right. The side that has more space install your crank assembler and pull the crank to fill up the gap till it looks like there is equal spacing. Then use the feeler gage to confirm. Keep adjusting till it's perfect. As far as wiseco crank and bearings I have no experience with them. I use oem honda bearings and crank. If it is not to late to return you might want to consider if it is to late just rock the crank and every time you change the piston or rebuild the top end keep an eye on it. In my opinion I don't think they are as bad as people make them out to be! You hear a lot of people use them and say they are great.

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There's your problem. The Wiseco crank and bearings are junk. 

 

 There were a few years when they had issues but they have resolved them now. 

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