New Owner: 2007 FS550E. Couple Questions.

Hi Billy,

there are a lot of main bearings in the NJ206 size that have nicer roller end radii than the stock SKF ones.

The problem with the mains is caused by the crank spreading with increasing RPM, the 550 crank is the heaviest of the 3 engines 04 and up and it has a little 32mm pin so it is not very rigid.

when the crank spreads it loads the bearings axially, the rollers butt up against the bearing lip, dig in and skid, then they fail due to having 2 kinds of misalignment at once and and being loaded axially at the same time. so if you ride mostly at low rpm it is likely never to be an issue. A lot of 550s ate their mains here in Aust around 50-60hrs, lots of wide open spaces.

if you do replace the mains it is worth noting that member ORANGEBERG found (when he used to be a dealer) that fitting NTN roller mains was a big improvement.

http://www.husaberg.org/forum/viewtopic ... 79&start=0
http://www.husaberg.org/forum/viewtopic.php?f=5&t=6195

I have tried the NTN and some Rollway bearings in my 628/700 and found them quite good.

there are other solutions but the nj206 rollers are the simplest to assemble

FWIW I use Delo400 15/40 though not available anymore in the US, its best equivalent is shell rotellaT.