View Full Version : Removing and installing engine case bearings 250R Questions.
TtownJoeShow
10-10-2011, 03:42 PM
hey, i'm staring to get ready to put my new engine bearings in my 85 250R and i'm wondering what is the best route. do i need a kit like the picture below, does it have the sizes i need?
133310
El Camexican
10-10-2011, 04:00 PM
Life is a lot easier with the right tools.
Dirtcrasher
10-10-2011, 04:30 PM
That looks like a general bearing installation kit, including blind bearing puller, nice to have.
You will still need a 20 ton press, an OEM shop service manual and various thin sleeves that can be made up of pipe of many sorts.
Realize, that you may not have the tools to do it, maybe you do?
Cranks have to be pulled into position without any sideload on the crank halves. Then they have crank holders etc etc, they can be done without but you have to "get" what can be damaged if you make a wrong move. There goes that rebuild that should last 25 years.......
Half the guys rebuilding 250R lower ends don't even know why (or if the even know) that the left crank seal needs to be set 4-5mm deeper than flush.
Lots of info in the searchable stuff, propane torches and a freezer are your best buddies :D
Don't neglect the counter balancer bearings and holder and bolts, they are just as important!
TtownJoeShow
10-10-2011, 04:44 PM
dam, no press here, 4' jack all lol maybe i should give it to a shop :/
stroberts22
10-10-2011, 09:36 PM
Anytime I ever rebuilt a bottom end I put the case halves in the oven and heated them up and the bearings just fell out even the blind bearings. Then when I reinstalled the bearings I put the bearings in the freezer overnight and the next day I put the case halves back in the oven. I heat them up till when a drop of water hits the case half it steams. I then take it out and drop bearings in and they push right in with little effort. When it cools the bearings are set. I would avoid putting a open flame to your cases though. Just my opinion.
El Camexican
10-11-2011, 05:09 PM
Anytime I ever rebuilt a bottom end I put the case halves in the oven and heated them up and the bearings just fell out even the blind bearings. Then when I reinstalled the bearings I put the bearings in the freezer overnight and the next day I put the case halves back in the oven. I heat them up till when a drop of water hits the case half it steams. I then take it out and drop bearings in and they push right in with little effort. When it cools the bearings are set. I would avoid putting a open flame to your cases though. Just my opinion.
Same for me, but for some reason my last project ended up with one of the mains a little cocked. Someone here (I think it was Mosh) said that sometimes if you do the bearings like this they can squirm back out a bit as they cool. I got mine seated right after, but there were some tense moments I'd have paid to avoid. I'll still be doing my next rebuild like this, so I hope that was a fluke.
TtownJoeShow
10-12-2011, 08:55 AM
interesting, might just have to give it a try.... worst case, buy another engine lol or cases :)
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