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sandman768
5/23/2017 9:36am
5/23/2017 9:36am
Edited Date/Time
6/30/2017 10:16am
1981 Suzuki RM250 restore. Found the reason why my crank shaft had so much play on the ignition side...there is a pressed in ring that makes up the bearing pocket in the case, while prepping the case for new bearings I noticed the ring is loose! I did a magnet test on the ring, appears to be aluminum as well. I"m thinking I can just "V" out around the ring & case and have a welder lay a bead around the circumference of the ring & case...any opinions or better methods? Cases are NLA... I bought a complete bottom end for the other side case that I needed, I checked the spare mag side case & the pressed ring is cracked & worn even more than my original. First photo shows my prepped case, the bearing pocket ring is loose in the case. The 2nd photo shows another case I have that the bearing pocket ring is actually cracked.
make a spud to fit seal bore
attach it to a flat steel plate
sweep in od of spud
install case half
clamp and true case surface to plate/ perpendicular to quill/ boring head
bore out old case sleeve/ true bore up
machine a new sleeve for a .002 press
and a .02-.05 undersize for the bearing
use a loctite on sleeve install
install case back on spud, same as above
bore back to size needed for bearing
I would make the case sleeve out of
bronze
The Shop
and use the quill to press in the
sleeve, and also recheck all your postions
and sufaces to make sure your case has
not moved
Harrys Machined Parts 508-366-1455
How come your local shop would not do it?
you do not need to remove any parent
material from the case, or maybe only
.01 to clean up
the cast in sleeve you are trying to remove
should have a 2-3 mm wall per side
your sleeve would have to be custom
machined to size , not a big deal
the only thing , cost issue time , materials
to make a fixture plate to hold case
and a chuck of bronze for the sleeve,
steel woul be fine
Pit Row
mount right to mill table
I had a set of RM465 cases, that had a destroyed set of swingarm pivot bore sleeves
they are cast into the case set the same way
I bored the sleeves out, made a new
bronze set, installed and machined back
to size, worked great
Same with a few rear hubs, that the bearing
bores were shot
same process
Case repaired & bearing installed...machinist stated it was a little more labor intensive than he estimated, mainly to get the old bearing sleeve out....This machinist/ bike shop restores a lot of old Japanese inline 4 engines, he stated they run across this type of repair all the time...... Figured I would include a proper ending to this thread, thanks for all who offered opinions & help....
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