Main Drive Bearing

[davej]

Fitted a FAG main Bearing in a 150 small block with a Mugello 198 Top End and have just done just under a 1000 miles, However have found that the Bearing is knackered, Has anyone else experienced the Bearing failing in a short space of time ?

[al pushpak]

Hi, I've never had much luck with FAG bearings , I always install them correctly with loads of heat to the casing yet whenever I've done any maintenance on the flywheel or engine casing sides I've found that they have developed "excessive play" after I've done a few hundred miles ! I've always bought them from reputable dealers & not used eBay knock off's & my engine isn't a highly tuned ts1 , I'm running KOYO mag & main bearings at the moment & on a recent check they seemed ok , I know others don't rate them highly but I just got fed up of fitting "high quality" FAG bearings only for them to fail once again afterall its not a 5 minute job to change them is it ? maybe worth trying something different , hope you get it sorted cheers

[HxPaul]

Fitted a FAG main Bearing in a 150 small block with a Mugello 198 Top End and have just done just under a 1000 miles, However have found that the Bearing is knackered, Has anyone else experienced the Bearing failing in a short space of time ?

Dont forget that drive side bearings are C3 meaning that they have more clearance(play)than other bearings.

[davej]

Thanks Al. I have always used the FAG bearings, This is the first time I have experienced a problem. Is there an alternative make you would recommend ?

[al pushpak]

No problem Dave, I'm currently running KOYO bearings (main & flywheel) which I mentioned in my reply, bought them from buzz solomoto , so far they seem ok, & as I stated I know others don't rate KOYO bearings but as with most things lambretta it's all about personal preference & whatever works for you good luck

[davej]

Finally removed offending bearing from Casing, Never have I seen so much movement between the Inner and Outer races however on inspection of the bearing I noticed that although it is marked FAG it is also marked Korea, Has FAG had these bearings manufactured in Korea for sometime or is this recent, On speaking to the Scooter suppliers they say they have not changed the people who supply them, Could these be replica's that has made thier way into the market place ? or do FAG as other suppliers do have them made in a different country ?

[davej]

On a foot note to this I have checked a FAG NU2205 which I keep as a spare, This bearing has India marked on it. Would FAG use two contries to make thier bearings ?

[rossclark]

Yes - in theory they're made to the same standards. Pays your money and tales your chance.

[Scooterdude]

I would suggest you have picked up some debris from inside the chain case if the bearing has lasted less than a thousand miles, or your chain is rediculously tight.

On several recent builds ive used the Koyo “M” speck bearing instead of the c3, the tolerance is tighter than the c3 and ive not had a problem.

Ive seen identical FAG bearings in identical boxes, some marked made in india and some marked made elsewhere (cant remember were now haha).