Forum

[stinkwheel]

When I used to be regularly fitting bearings/cranks in the shonky eastern european 2-strokes which were all I could afford to buy, the saying was that you needed the casings "Jesus hot".



How do you know they are "Jesus hot"? Touch them. If you say "Jesus" and suck your fingers, they are ready.



These days I take the whole lot to a man with properly fitting arbours and a hydraulic press.

[Revband]

Heat is the best way to fit bearing into alloy castings, using a press is risky.read Tim's post above it can and does damage the housing.

[stinkwheel]

I wonder how they fit them at the factory?

[Bullet Whisperer]

With a big hammer?

[gord]

Hello
When removing the timing side main bearing of my Constellation, I used a hot air gun with an assembly of made up pins and a machined support ring with a large screwed rod and nuts to gently pull it out. For reassembly of the new bearing I again used a hot air gun and the bearing in the freezer. The hot air gun can be used to keep the case hot while you work and I had no problem at all.
I could send pictures of my home made rig if of interest.3

[scotty]

Hi i also use a heat gun freeze bearings in freezer for a couple of days , had a rel who does woodturning make up a set of hardwood drifts spigot through bearing and lip to sit on outside rim of bearing lets you get bearing square the a light tap and its in. Have also similar but much longer one made so l can change the large gearbox driveside one without having to remove gearbox case from bike ,just have to support outside of box end with something heavy and solid,works a treat but spigot should only go threequarter way into bearing so as not to hit what you use to support g box end.