7.5 k/b pro outboard sealed bearing ?

[bob miller]

is it ok to use a sealed bearing top of motor under the flywheel or should I remove the bearing seal ??? thanks....bob

 

[Alan Elzer]

I leave one side in weather it's a rubber or metal seal

 

[Arthur Apruzzese]

Here's the difference: If it has rubber or plastic it is a "sealed bearing", in which case there is actual contact as it rotates. If it has metal instead, it is a "shielded" bearing, in which case there is a miniscule amount of "clearance" and no actual contact as it rotates! For high rpm racing engines, the inner (facing the crankshaft) "shield" or "seal should always be removed for proper lubrication AND longevity.

 

[bob miller]

the bearing is the metal shielded type and the inner side faceing the internals of the motor is not shielded.....thanks for explaining the two types of bearings.....bob

 

[BradSpencer]

After doing some leak down testing on engine crankcase pressure, I have found the double rubber sealed front bearings hold much better crankcase pressure(approx. 10% more on most engines tested).

I have not experienced any premature bearing failure by leaving both rubber seals installed on the front bearing on IB and OB engines.

For me its a no brainer. Go for a rubber sealed front bearing and leave both rubber seals installed.

After testing, I now do this with all my OS, Nova and K&B engines.

My 2 cents from what I have found, contrary to common practice