Last year my flywheel side crank bearing seized with around 4000 miles on it. Tore the motor down last year and replaced all the outside crank bearings. Put the sled back together and ran good. 100 miles later the same thing has occurred. Any ideas.
Yamaha SX 700 Crank Bearings Problems
- Thread starter SRXLance
- Start date
thefindian
New member
Are you sure you had the oil journals lined up on the bearing or you got a bottom oil line problem maybe.
mbarryracing
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- Aug 30, 2007
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Call Justin at FPP (sponsor), he is a wizard with those 700's and could tell you what caused that.
As thefinian said, make sure those holes in the case and bearing were lined up. Also check the passage in the case to make sure its clear
nytrodave
New member
I just re-assembled my 700sx, the crank bearings have small roll pins (anti rotation) that sit in little pockets that are cast into the case half, there arnt any oil holes in the bearing. The bearing is lubed by little grooves in the top of the case half that have holes up thru the top half of the case to the bottom of the cylinder. As the piston comes thru bottom dead center the fuel air and oil mixture is compressed in the base and some of it passes thru the bearing and up thru the oiling groove to the top end, this allows a small amount of oil to stay in the bearing. Not sure why you are having problems? Perhaps the crank is out of true causing stress/vibration in the bearing? Is the oil pump bled, adjusted and working properly?