Any know from experience if these screws could be left out?
Would the bearings move without them?

 

I always use them in customer engines, and if the old ones get mangled I order new set screws from Ray at Malloy Mazda, 888 533 3400.

Presumably Mazda had a reason for going to the trouble of using them.

 

Thanks, that's what someone else has told me as well so I am going to replace them.

 

Would you happen to know if this is the correct part number?

992220612

 

Part # NF01-10-E09, it is technically called a stopper pin

It is not a good idea to leave them out.

 

i have heard of people using loctite on the bearing instead, and I once built a motor without one because I couldnt find it and it was a crap motor anyway, never had a problem with that engine. BUT I wouldn't recommend leaving them out, there is a lot of thermal expansion in these engines and you don't want that bearing to spin and ruin your motor all because of a stupid setscrew.