Author Topic: How to safely split your engine cases.  (Read 3966 times)

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Offline sandblaster

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How to safely split your engine cases.
« on: June 09, 2011, 10:09:41 AM »
Here is a problem that veteran engine guys will laugh about.
However, for the uninitiated, this can be an intimidating situation.
You need to replace your crank shaft.
So, you have removed your engine from your bike.
You have removed all the bolts, springs, snap rings, cylinder, linkage, ect from your engine.
Here is what your are left with.



In this case, I used a 93 KX500 Engine.
Some guys will grab a hammer and start beating the transmission shafts to split the cases.
While this can in some situations work, you always take the chance of damaging your shafts, cases, gears, ect.
The solution is to buy, beg, or borrow a engine case splitter.
This one is a Motion Pro but there are many on the market that work just the same.



#1 rule. DO NOT BE IN A HURRY.
Engine cases are expensive and can easily be broken.
Before you get started, take the time to clean the threaded areas carefully and even run a test bolt or chase the threads with the correct size tap if required.
Oil all the threaded rods, set nuts, and threaded holes.
Next, assemble your tool.
Slip the arms onto the main shaft.



Then hand tighten the set nut.



« Last Edit: June 09, 2011, 01:41:02 PM by sandblaster »
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: How to safely split your engine cases.
« Reply #1 on: June 09, 2011, 10:15:09 AM »
Next, slip on the centering tool on the end of the shaft.



Then run the threaded rods through the arms with the retaining washers and set nuts.
Try to spread them out as evenly as possible so that you get even pulling pressure on the cases.



Hand tighten all the set nuts so that the center axis of the pulling tool shaft is in line with the center axis of the crank.
I know it's tempting to use a ratchet or a impact gun but please resist the temptation and use a hand wrench.
Yes, it takes a bit longer but your tool will last longer and you will not be as apt to strip the threads in your cases.
Once the bolts are snug and the axis of the puller is properly aligned with the crank, start tightening the main puller shaft bolt.
Within a half to a full turn you will usually hear the cases pop.



Check the back of your case to make sure it is not pinching at the back while split in the front of the cases.
If that happens you may need to loosen all the bolts and move them around to get more pulling power on one end of the cases over the other.
Once again, do not be in a hurry.



All done  :-o
Usually it takes me about 10 minutes to pull all the tools out, split the cases and put the tools away.
Piece of cake!
« Last Edit: June 09, 2011, 10:56:21 AM by sandblaster »
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Motorrad

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Re: How to safely split your engine cases.
« Reply #2 on: June 09, 2011, 10:26:46 AM »
I like to use 2 pullers on my motors... One pushing on the crank, other pushing on the countershaft.. 

But I do recall the term "anal" used to describe me before...

Offline sandblaster

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Re: How to safely split your engine cases.
« Reply #3 on: June 09, 2011, 10:59:46 AM »
The next time you use two pullers, take some pics of your setup as I'm sure others would like to benefit from the how too :-)
I've never had the occasion to use two pullers but I'm sure sooner or later I'll need it.
« Last Edit: June 09, 2011, 01:39:27 PM by sandblaster »
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline The Flyin Hawaiian

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Re: How to safely split your engine cases.
« Reply #4 on: June 09, 2011, 11:01:18 AM »
Thats the same splitter I have, I think its a Motion Pro.
A couple of 03 and 04 KXs, a few YZs, 3 PE 400s, a DR and a TS.

Offline Friar-Tuck

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Offline sandblaster

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Re: How to safely split your engine cases.
« Reply #6 on: June 09, 2011, 01:41:36 PM »
Thanks!
I found my receipt and it is a Motion Pro...
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline 81cr450

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Re: How to safely split your engine cases.
« Reply #7 on: June 09, 2011, 01:51:39 PM »
I've been working on my own stuff & friends stuff for the last 20yrs, & just barely found this tool a year ago. This kind of wisdom is why I'm reading through all you alls posts.  Its real bear trying to pry & rubber mallet at the same time all while not gouging the sealing surface. There's a tool for every job & a right way & wrong way, Its nice to have people who share stuff like this tool
if I only had a pair, I could actually ride this thing

& to the people I like  FYYFF

Offline snoopjonnyjon

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Re: How to safely split your engine cases.
« Reply #8 on: June 10, 2011, 03:13:29 AM »
I like to use 2 pullers on my motors... One pushing on the crank, other pushing on the countershaft.. 

But I do recall the term "anal" used to describe me before...

You really are anal.

I've always just pushed on the crank, and very lightly tapped the countershaft with a small rubber hammer.

Offline gwcrim

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Re: How to safely split your engine cases.
« Reply #9 on: June 10, 2011, 10:46:21 AM »

The solution is to buy, beg, or borrow a engine case splitter.

Hey..... can I beg or borrow your case splitter and a cup of sugar???? :-D

~Crim~
You raise the blade
You make the change
You rearrange me 'til I'm sane

Offline 81cr450

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Re: How to safely split your engine cases.
« Reply #10 on: June 10, 2011, 01:29:25 PM »
The sugar probably, but the tool he makes his bread with I'd doubt it :-D
if I only had a pair, I could actually ride this thing

& to the people I like  FYYFF

Offline sandblaster

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Re: How to safely split your engine cases.
« Reply #11 on: June 11, 2011, 04:00:10 AM »

The solution is to buy, beg, or borrow a engine case splitter.

Hey..... can I beg or borrow your case splitter and a cup of sugar???? :-D



Come on over and I'll do it for you....
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.