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HELP PLEASE!!!

I just replaced the crank and main bearings on a 2010 KX250F with a Hot Rods crank and bearings kit.  All went well during the rebuild thus far.  When I attempt to torque (87inlb) the case bolts the crank starts to tighten up and gets worse at the case gap closes tighter. 

The bearings are seated all of the way.  I've pulled the bearings and re-installed them to make sure that they were seated correctly.  Upon inspection i noticed that the Hot Rods crank is wider than the OEM crank by roughly 1 mm.  Total length is the same but the actual crank body is a little wider. 

I can see a very small gap between both sides of the crank and left / right case halves.  However, the gap is a little bigger on the right side.  The crank does not appear to be rubbing on the case though.  See picture below.  I can't find what the spec for this gap measurement is in the manual. 

My guess is that the crank being 1 mm wider than the stock is putting the bearings in a bind when I try to torque the 8mm case bolts.   Any help would be appreciated.  Not sure where to go from here and could use some advice.  

case left.jpg

case right.jpg

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Are you sure the bearings were seated flush? “Tap” the closer end of the crank with a rubber mallet. Don’t try to get the crank centered, just try to move it a tiny bit to see if that changes anything. 

You can search “crank binding” and find tons of post with other ideas.

Let us know what you find.

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Thanks for the reply.

I seated the bearings by heating the cases to 180F and cooling the bearings to -10F.  They dropped in perfectly and I held them in place for 1 minute to make sure they didn't work their way out.  I installed the crank using the same method (heated bearing and froze crank) on the first case half and used a Tusk puller on the other half.  I don't have oil seals installed at the moment and can see both bearings bottoming out.  I've tried three times and i get the same result.  I now feel like a bearing sweating pro 🙂 .

Gap between big end and cases are 0.027" on the tight side (R) and 0.035" on the other (L).  I beat the snot out of it with a rubber mallet from the right side and couldn't get it to budge.  Still in a bind......  Is this difference (0.008") enough to give the trouble or do you think something else is going on?

Also, do you think the 1 mm difference in width from original OEM is a defect in the HotRods crank or do you think it the OEM just wore away?  It had A LOT of hours on it.

I may just bring it to a local mechanic this week to see what they think.  I'll let you know what we come up with.

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Sounds like the bearings went like they should. Your pics looked like it was farther off than it was but I don’t think .008 would be the issue.

The 1mm in difference probably would though. When you take them apart do you see any rubbing on the cases? Call Hot Rods and take it to a mech like you said. Sorry this is happening too, always a bummer when new stuff doesn’t fit.

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