Checking NC engine bearings...

[ecurbruce]

B.Bob,
So, are you saying you like your RARE parts more towards MEDIUM-WELL?
In the south, we prefer baked beans and iced-tea

[blaat!]

Anybody have experience with Nachi or VXB bearings?

[joe46ho]

Nachi Cant be beat for the price... I use them exclusively, unless I need a specialty bearing that I cant get from them... And I also exclusively use VXB/Nationskander as my supplier for them, there prices cant be beat on Nachi... If I just need one bearing and Im in a hurry I get it at my local dealer (BDI) and it usually costs twice as much. VXB offers several shipping options but even if you select the economy (take your time) shipping option on there site. they still ship ups ground, and very cheap too... The only 2 bearings that you cant get from them in the nachi brand are the 1202 upper bevel shaft bearing, and the clutch basket/primary gear bearings... but they do offer them in another brand. I have placed 4 large orders with them over the past 6 months with zero problems...

Joe

[blaat!]

Thanks Joe. Glad to hear positive stuff about them. I'm thinking of buying through VXB for my NC rebuild.
-Jim

[blaat!]

Does this look about right for a 250 Narrow Case? I think this covers every ball bearing in the engine. Anybody see any errors or ommisions? Thanks!






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[joe46ho]

Thats pretty much it, with a couple exceptions... I would not buy the 7202b vxb bearings they are junk, for about $2 more you can get a pair of nachi 7202 from the same place...

Also there is a set of 15, 7mm rollers in the gearbox, Sometimes you can re-use them though. If not I get those from lacey engineering.

Also there is 3/16", 1/4", and 11/32 " loose bearing balls used throughout. These are very cheap from vxb you might want to get those there too, (3/16" also used at the frame head)

If you have lost your 5mm clutch rollers, these are also very cheap from lacey engineering...

And if you are reconditioning your wheels and hubs, its also a good time to buy those bearings... 6202-2nse qty. 4, and 6004-2nse qty 1, (some late hubs like my brothers 450scr i noticed have 2 6004's so you should probably check 1st)

[blaat!]

Thanks Joe. I'm not at home right now to check, but I don't reacall any of the bearings having seals when I did the tear-down. I noticed that several people have reccomended using sealed bearings (with the seal on one side pryed out) for the two shaft bearings on the chain side. Is adding sealed bearings a non-oem improvement, or did I just overlook the sealed bearings? Is it easy to pry out the seals without damaging the bearings? Just go at it with a sharp instrument and a pair of needle nose?
-Jim

[joe46ho]

If you havent removed the case bearings on the chain side, then you wouldnt have seen any seals or shields yet anyway, but thats the only place you will see them...

The bearings I took out of my engine had sort of a hybrid shielded/sealed bearing (steel shield, with a sealing lip that rode against the inner race) . I really doubt you would be able to find the exact ones anymore. You could probably also use shielded bearings, I have just been told to use sealed bearings, and I dont see any reason not too. The only spot it really matters is at the output shaft where the sprocket slides over, you will notice there is a shim/slinger there that is below the bearing, I think this will help keep the new bearing seal from getting damaged by debris/dirt from the chain... if you used a fully open bearing here it would surely leak oil, maybe not a lot, maybe a ton, I have no idea... I know I prefer to lube my chain myself, the only thing I want a chain oiler on is my chainsaw... the other bearing on that side of the case still has the clutch pushrod or "peg" seal to stop the oil, but there again, I dont see any reason not to use a sealed bearing. In any case, yes you just pop one seal out, it takes 2 seconds, just use a small flat blade. If you have steel shields they are a little harder to remove, but still no big deal... If your ordering bearings and you really want to, you can order a "rs" or "nse"instead of a 2rs, or 2nse, and it will only have one seal, but that is pointless because A: vxb and others usually dont stock them, because everyone just buys the double sealed bearings, and pops one out, and B: they are usually the exact same price.

joe