What size are the main crank bearings??

GoldenMotor.com

UVsaturated

New Member
May 15, 2008
140
4
0
Dayton, Ohio
Anyone know what the physical size of the main bearings are? I don't have any mics handy and want to know if anyone has the dimensions off hand. Are they metric or english? I need the internal and outside dia. I'm looking to see if I can find a US supplier locally that sells the same size.

Inside the case the side with the magneto has a sealed ball bearing, yet the opposite side has an open ball bearing but it then has a rubber shaft seal to hold in the crankcase pressure.

I had the magneto side bearing shield disintegrate and caused a huge vacuum leak.
 

supercub

New Member
Nov 1, 2012
56
0
0
New London, CT
Try bearing distributors. They have outlets everywhere. Just give them the ID,OD, and width and specify only non-chinese roller open bearings. Also buy your single lip seals from them. Tell them the seals need to be gasoline compatible. Install with both lips facing the clutch side. I use their bearings for all of my moped rebuilds.