Installing new crank advice?

[Will'smotobikes19]

Well I'm about ready to start putting together the motor i'm building. I noticed when I was trying to fit the crankshaft it wouldn't slide onto the bearing it had to be tapped or pressed. Is that normal? I hit the one end with a block of wood but I don't want to make it out of balance so I stopped. What is the best way to install a new crankshaft? I heard its bad to have an unbalanced crank and by hitting it it barely moved on the inside of the bearing. I don't feel like it should be that hard to install it. The crankshaft isn't connected in the middle and I feel like I could have messed it up by hitting it in the middle. I'm using Nachi 6202 bearings and a 3mm stroker crank.

 

[Will'smotobikes19]

Well I realize now I should have heated the crankcase and put the crankshaft in the freezer instead of hitting it. I don't know what I was thinking. People seem to think that I have to balance it but I don't know how. the piston is 47.79mm because its a big bore cylinder. Do I have to take it to a motorcycle shop or something? I'm sure hitting it didn't help it and its on the one side of the crankshaft should I heat the whole thing and seat it or remove it? I don't have a dial indicator.

 

[crassius]

I usually stick a chunk of steel (then a few leaves from a feeler gauge to get it snug) between the crank wheels when working on fitting it.

 

[Will'smotobikes19]

That's what I was thinking putting something in between the gap I couldn't find anything the right size. Just got the sick bike parts head studs in the mail. I might heat up the whole crank and case half then tap it on the whole way then put the crank and the half in the freezer so its easier to put the other half together.

 

[crassius]

never too late to start throwing old feeler gauges into a box when bent or rusty to have handy shim stock for spacing loose bearings and other uses