I press bearings out and in now, but you can also use a oven. The aluminum cases expand faster than the steel bearing (thermal expansion of differing materials), so if you put them in a 350 deg F. oven for about 10 m minutes (I remove the seals and replace them with new ones later), the bearings fall right out (or lightly taped if needed). You can also drop new bearings in the hot cases, and even hear if hit bottom if you drop it straight enough, (but can get suck half way down, crooked, if you don't, requiring re-heating to remove them safely; but I have returned to pressing them in and out to avoid burnt fingers. Doug @ ESP
The ultimately best way to remove and install bearing is to heat the metal up to about 130-140F and they will both drop in seated properly and fall right out.
This vid is all well and good, but to remove the crank bearings the best method is heat. Remove the snap ring if you want, put the case in the oven for 10 mins on full power. Then if the bearing on the upside down side has not already fallen out just tap it very soft and it will come out, turn it over and tap it and the other will fall out. Now put it back in the oven for just a few mins, have your new bearings in the fridge for half hr before hand, or 5 mins in the freezer after you have had the case in the oven for 5 mins. Then once the bearings are cold the crank is warm the 2 just fall right in, hitting bearings your way will slightly oval the bore. The reason this works is alloy conducts heat faster than steel, so the alloy expands quicker than the bearings. Simples
i have a cy motor and i changed the crank seals and bearings but i see on one half of ur crank u put two bearings but on mine it comes both with a rubber seal is it better to use two bearings than a rubber seal on the side u had two bearings?
