Crank bearings on my 71 yamaha DT1?

[moturbopar]

Hi, I picked up a 71 dt1 the other day for $75. It hasnt been run in almost 18 years. I pulled the head and cylinder and it all looked like new, rebuilt the carb, and put new points condenser in and a new woodruf key. It now starts and runs great! fires every time on the first kick. The only problem I found is that it has a metalic knock in the lower end and a slight grumbling sound, I drove it around yesterday and could barely hear it, but today it is much louder. It does this with the clutch in or out, so I am pretty sure its not anything in the trans. I pulled the head and cylinder off again and the rod and piston bearings are nice and tight, no excessive play. I did find that I can move the crankshaft (on the flywheel side) up and down, not much but it makes a slight metalic sound. Does this sound like it needs crank bearings? And are the crank bearings pressed onto the crank?
Thanks for any help!
Shawn

 

[originaldirt]

Any non-radial movement of crank bearings indicates replacement is necessary.

OriginalDirt

 

[moturbopar]

Cool Thanks! thats what I figured, just wanted to check befor I pulled it apart for nothing.

 

[Ryan12833]

you probably know but you can take the bottom end apart yourself all the way down to the crank without one single special tool.

 

[Imack]

Sometimes may not be that simple, I have a 1985 Husky 250 that had the same play in the flywheel side, when inspecting found out that the bearing was bad, so...replaced the bearing and then found out that the metal insert worwe out the aluminum on the crankcase. So, I machined out the insert, placed a fabricated one, then with the new bearing things went back to normal.. Sometimes when one of the crankshaft bearings fails, it also will damage the big eye rod bearings, so check them out while yoyu are there..!

Good luck