KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: BLACKBEARD on March 30, 2016, 05:51:11 AM
-
I just put new bearings and new seals in.
After I put the seals in and tightened the cases, the crank didn't move as freely as I thought it should.
Could this be because I didn't grease the seals??
As always anything helps, and thanks in advance.
-
Is it a 250 or 125? What year is it? What did you use as far as replacement parts?
-
there should be next to no resistance when you try to spin the crank....if you feel resistance, or hear anything scraping or dragging, chances are, you'll have to open it back up and find out where things went wrong.
with new bearings, that thing should turn smoothly, and easily with the cylinder off.
you can try to post a vid, but without actually being there and feeling it for ourselves, it's kinda hard to give an accurate answer.
-
It's an 03 with new rod bearings crank bearings and new seals.
-
It's a 125.
I don't hear or feel anything throughout the whole rotation, just really really stiff. I don't know how to post a video, I'll try to figure that out later.
For now I will be tearing it back apart tonight to figure this out.
-
Easiest way to post video is through YouTube
-
Is the crank centered in the cases? If you are off one side or the other there will be resistance and will not turn easlily.
-
Ok this might help...
When I tighten the case screws, the crank has more resistance.
When screws are loosened the crank turns freely.
-
I'd check the crank to case clearance on both sides.
If it is centered I would split the cases and take a good look at how well my bearings are pressed in.
If they are not completely pressed in then you could be rubbing and not see it.
-
Ok... so the RH crank seal was pressed all the way against the bearing.
When I pulled the crank back out, I tried turning the bearing with my finger and it was seized. As soon as I pulled the seal off it was free.
-
Easy fix :lol:
-
I've never had a seal do that to me....yet!(knock on wood).
-
Put it back together without the seals...
Same thing, tighten the screws and it gets stiff.
-
I always use a soft hammer and hit both ends of the crank back and forth when the cases are still hot it centers the crank and almost always frees it up. if you dont use a wedge or the proper tool to keep the crank true I have seen the cranks get in a bind and whacking the ends will usually straighten that out use a soft hammer though
-
I use to do it the same way.
Now I measure before I assemble so I know the total clearance between the crank and the cases.
Then I divide it in half and get out a feeler gauge and put the feeler gauge on the bottom case so when I drop in the crank it is automatically centered. 8-)
-
I do believe that the crank is not seated in the bearings.
I will use the technique that Tobys two strokes referred to.
I'm hoping this is the solution (crank not seated). I am really getting frustrated and bothered by it. If it wasn't my first bottom end I'd be a little more at ease.
Thanks for ALL the support.
-
I would almost guarantee, almost guarantee, this is the problem, the crank is not seated and it has a load on the bearings. Any time you are going to tap on the crank you need to support the halves opposite the pin, it takes a pretty good hit to move it and without support you could cause a mis alignment. any misalignment will cause vibration, the amount of vibration is proportional to the mis alignment. I use the heat cold method and usually do not have any binding issues.
-
So I'm gonna take the crank out, put it in the freezer. At which point am I gonna hit it with the hammer? When both cases are on, or one at a time?