Hey guys had a quick question for yall. I am looking online at the various engine bearings for a trx 3.3 engine that I believe the front bearing may have a leak. Anyway I have looked a few different places and notice that the front bearing is a 7x17x5 and the rear bearing is a 12x21x5. I understand the sizing and the differences between a normal and ceramic bearing as well as the different shield types on bearings. What I don't understand is why is there a regular rubber sealed 7x17x5 and then an engine specific 7x17x5 that costs $5 instead of $1 like the regular bearing? The same thing with the 12x21x5 bearing. The regular one is $1 and the engine specific one is $8.
Could the shields be pulled off that bearing and used inside the engine? I do not mind paying the $13 dollars for the new bearings if needed, but if I can buy sets for 5 engines for $10 total I would rather do it. What gives here?