'83 CR250 motor needs crank seals. Plan to.....

The parts came so pretty soon I'm gonna split the cases and re-new both seals. I going to use an old Can-Am motor splitting tool along with an attachment plate drilled to fasten to either the 3 mag cover bolt holes or on the opposite side at the primary gear..
Am I ok planning to pull the right side 1/2 case off first... leaving the entire trans intact in the 1/2case on the clutch side?
Then, use same tool on the pri. gear side to push the crank out of that 1/2 case? Don't plan to even disassemble the clutch, shifting mechanisms, or trans. shafts.

And last, I'm assuming when pushing motor apart the crank main bearings are going to/supposed to stay in the cases not stay on the crank?
Thanks, Dave.

Yes you can leave the transmission and clutch intact in the left centercase. I just did that on a 79 390WR engine and pushed the crank out of the left side. You may need to remove the clutch in order to remove the primary gear on left end of crank. You will need a puller for that but I got one from NAPA and ground the inside so it would slip over gear properly

If I were you I would go ahead and dis-assemble everything. Inspect the gears and shift forks/drum. Pay attention to the crank main bearings .Good enough isn't! I had a loose main bearing on the primary side-I thought it would be O.K. because there was little weight on that side of the crank. Boy was I wrong-it vibrated like mad. I had to re split the cases to replace that bearing. The moral of the story is check everything once and you won't have to go back in later.

bearings are cheap c/w the effort to get them out so just replace em all and it will be spot on

When you remove the crank, be aware there is a 2mm thick spacer on the right side - between the crank cheek and the double row main bearing!

This often sticks to the bearing and drops out when you are not looking...


You can use the crank nuts and some spacers to 'wind' the crank back into the cases in leu of the husky tool, but go gentle on the threaded crank ends.

Andy Elliott

Thanks for mention of 2mm shim/washer on ignition side. I see where it could stick to bearing then fall off when your not looking.
And so.... the main bearings are expected to stay in the cases?

Is there any particular "issues" this 1983 model year CR250 engine might inherently have that I should pay attention to?
I feel I got a gem of a motor in this bike... with a std. ring in it and .018" end gap, it might even be the original ring !
Maybe only because of shear age is the ignition side crank seal leaking. ( I hear it hissing air as soon as any slight positive air pressure is pumped into crank chamber...won't even build to 1/2 psi....leaks that fast.)
dfave

Grab hold of the Right side crank end and see if you have play up and down. One of my race bikes does let a little 2t oil pass the right side seal if you thrash it to death. I don't worry too much about this because we always fit one of our Aluminium Ignition covers and they seal up much better than the warped plastic ones - so, it won't be letting air in...

Andy

Yes. I was surprised how freely air leaks thru that seal to the Motoplat. So freely the hand pump I use would not even deliver enough positive pressure to hardly display units of PSI. Re-ranging inst. for inches/H2O better illustrated how fast it dropped off. (I could hear it hissing).
Separate note: All those years Husky used double row bearings both sides crank, wonder why they switched to two single bearings together on the primary side? Cost?

If you are going to all the trouble of splitting the cases, do yourself a favor and replace all the bearings and seals. It will probably cost you a whopping $200 but you will have a complete engine. You can purchase a case-splitting tool on Ebay for $65. Take pictures of the dis-assembly and use zip ties for the end of the transmission shafts. When assembling, keep in mind the trans has to be in 4th gear (on a six-speed gearbox) and 3rd gear (on a five-speed gearbox) and the stepfeeder gear has to have two teeth visible on the left side of the shifting barrel, and one tooth on the right side as shown below. If you don't get this right, you will be splitting the case again to correct your mistake.

That does not apply on the 83 250CR he is asking about

I would change the crank bearings for sure. But ditto above change all the bearings and seals too plus some o rings where applicable. They you'll have a trouble, problem free bottom end. What about the piston and cylinder? Since its apart change it now why wait till it goes it may damage the cylinder.

Your right Jim. My thread pertains to years that used the stepfeeder gear.

Thanks for the picture you posted as I have to assemble a 390WR engine soon

If you have any questions on assembly, my phone is 714-296-7094.

I fabricated my own tools for splitting cases and assembling cases. For splitting I took a 3/16" x 6" square steel plate and drilled a hole through it in the center. Then I welded a 1" x 4" pipe to it. I then welded a nut to the pipe and took a piece of threaded rod and welded a nut to it for the pusher. I tranfered the holes on the block on the clutch cover and ignition cover.

For assembling the cases I welded the primary crank gear to a threaded rod for the tranny side and used a ignition flywheel nut and welded a piece of threaded rod to that. I had a piece of 3/16" thick x6" square plate with a hole drilled in the center with a 1" x 4" pipe welded to the plate. I used a few flat washers on the threaded rod so the crank could be pulled in to the cases.

Thank you Puckerbrush. I actually have complete PDF shop manuals for everything I have but of course depending the resolution of the scanner that created the files the visual quality leaves something to be desired

The problem with using the 6" steel plate to screw into the mag side of the case, is the earlier models (oval case) and later models with 3 screw mag covers have different screw hole locations. With this design, it uses the same case saver flange holes that Husqvarna has used in most all air-cooled models.
http://www.ebay.com/itm/1968-1985-H...Parts_Accessories&hash=item3ce290cc4b&vxp=mtr

http://hva-factory.com/bottom-end-gearbox/husqvarna-primary-kick-2t-crank-case-shaft-separating-tool