KX65... Problem Splitting Cases

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mxracer2000

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Jan 6, 2000
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This is the first time Ive split the cases on this or any bike and I'm having some trouble. According to the service manual, I have everything removed that Im supposed to but the case is not separating evenly. Ive enclosed a couple of pics and hopefully someone who has done this might spot my problem. I've tried a rubber mallet as well with no luck.
 

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IndyMX

Crash Test Dummy
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Jul 18, 2006
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Amo, IN
It looks like it's binding at the back.. So, carefully use something like a large flat screwdriver to help it along at the back on the part where the cases meet at the swing arm mount..

Keep the screw driver out toward the edge though, so you don't ruin a sealing surface..

Best bet is to move it in small increments all the way around, so you may want to close the gap at the front.

They'll bind on the dowels, and once you get those clear it should fall apart.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
8,129
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Merrillville,Indiana
You seem to be too crooked between the front and back, it is bound up. Close the front till its even, then resume separation more evenly. No screwdrivers please, a dead blow or similar hammer. This is when the fancy separator really comes in handy, and better to have 2 of them, 1 on the crank, and 1 on the counter shaft. At any rate, keep it even, and drive the counter shaft and crank end to separate. Vintage Bob
 

Ol'89r

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Jan 27, 2000
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Remove the flat plate on the right side case with the two screw holes from around the shift drum. That is what is holding the cases together. The shift drum has to slide through the case along with the gear shafts.

Either that or remove the counter shaft sprocket and remove the left side case. Keep all screwdrivers away from the cases. They are not pry bars and they will damage the sealing surface no mater how careful you are. :coocoo: If the main bearings are binding, use a small torch to heat the cases. On the KX65 and many two strokes, it's easier to remove the left case and leave everything undisturbed in the right case. Tap on the shaft with a soft hammer as you push on the crank with your seperator tool to keep the two cases parallel to oneanother.

Good luck. :cool:
 
M

mxracer2000

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Jan 6, 2000
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I left the retainer plate and that allen head bolt in place because there is no mention of removing them in the service manual that I could find for splitting the cases. I saw a KX60 case splitting video on youtube and they were both left in place. I do have the countershaft sprocket on and I'll see if it makes a difference taking it off.
The reason Im splitting the cases is the bike developed a weird noise in the bottom end on our last ride of the season. I thought for sure it was the crank but looking at it now Im not so sure.
 

Ol'89r

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Jan 27, 2000
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That plate has to be removed. It is holding the shift drum in the case. The shift drum is attached to the gears through the shift forks. It all comes out as an assembly. If you remove the C/S sprocket, you will find it much easier to remove the left case. Then remove the gearshafts, shift drum and shift forks as an assembly from the right side case. With that retaining plate removed, they will slide right out. Reverse that proceedure to put it back together.
 

Patman

Pantless Wonder
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Dec 26, 1999
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The way I see it ya' got two choices. You can either listen to the youtube video and just crank and pry on things until they bust

OR

Follow 89'ers advice.

The choice is yours.
 
M

mxracer2000

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Jan 6, 2000
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Thanks guys for the info. I'll be attempting to re-tackle this tomorrow and hopefully with better luck.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
8,129
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Merrillville,Indiana
Pfft! I totally missed the countershaft sprocket! Both cases need to be stripped, in order to remove the main bearings and seals. The clutch bearing and the other 3 are begging to get changed, with the other few seals. Junior has a completely fresh engine. The angle in that pic, I sure hope that did not bend a fork! Never get that out of alignment. The more you can keep the cases even the better. Is that the motion pro case splitter?
 
M

mxracer2000

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Jan 6, 2000
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Turns out the countershaft sprocket was the answer. The cases are split but unfortunately no clear answer as to why the bike was dying and was making a strange noise from the bottom end. The crank bearings look good and everything else seems fine to my novice eye. Might have to take it to a shop for an assessment. Thanks again for the help.
 

Patman

Pantless Wonder
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Dec 26, 1999
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Spend the money on new parts and you won't have to worry about the noises. A few hours of shop time would cover most everything needed for the bottom end. If you don't see any obvious damage chances are it's the crank assy anyway. Worst case you know how to do the job now.
 
M

mxracer2000

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Jan 6, 2000
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Are you suggesting I go with something like a Wiseco complete bottom end rebuild kit that would include complete crankshaft, gasket kit, main bearings, and seals. Do you think I would need anything else?
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
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Merrillville,Indiana
mxracer2000 said:
Are you suggesting I go with something like a Wiseco complete bottom end rebuild kit that would include complete crankshaft, gasket kit, main bearings, and seals. Do you think I would need anything else?
Click to expand...
A Wiseco complete engine kit.
 
P

pesky nz

Member
Sep 13, 2010
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looking at your second picture old 89r is correct. If you remove the plate and even up the cases they will come apart with a tap from a rubber or plastic hammer. At reassembly time most KX cases are a very tight fit around the main bearings and need to be heated with hair dryer/ paint stripper type hot air gun. A simple way to know how hot is just right is spray wd40 on your bearing and heat until wd40 emits the first whisp of smoke move the hot air in a circular motion and dont point the heat at the main seals.
 
M

mxracer2000

Member
Jan 6, 2000
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Is a Wiseco complete engine kit different than there bottom end rebuild kit. I don't think Ive ever seen a complete engine kit. Do you have a link for one?
 
M

mxracer2000

Member
Jan 6, 2000
100
0
Not sure how i missed it initially but it looks like a couple rollers on the big end bearing were toast. Problem solved.
 
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