Chinese seals & bearings

[trappermike]

But if I had to put new bearings and seals into a motor,in a major overhaul would I try to save $5 on Chinese parts,not a chance . However I do buy parts from China and they can be excellent,but I would go to a bearing distributor and buy better parts for this job,cheap bearings and 13,000 rpm is not a recipe for long luck.

 

[Huskybill]

Buy them at a bearing supplier 10 at a time.

 

[Huskybill]

Buy them at a bearing supplier 10 at a time.

 

[Rennsman]

Regarding the seals.

The answers there will be revealed with time, the quality of antioxidants and plasticisers used will be crucial for long life, something easily cheaped out on, with no immediate indicators.

Obviously as things become NLA or outrageously expensive the temptation to use cheap or alternative items becomes stronger, but (important) rubber items are never something to save money on.

But realistically many of the saws here are low use, so any mechanical parts that appear up to the task when installed will probably live a long happy life (bearings withstanding), but that lovely pliable rubber/polymer part, if it's not borne of quality it's going to degarde and fail if used or not.

Would I use AM seals, in my own saws, yeah, they aren't normally hard to change, and failures will be noticed and non catastrophic, saws that run every day? something else will probably fail first.

I imagine people here would have received the occasion old stock rubber item, only to find it perished?

That said, in my real job, I will not use non branded rubber products of any kind, unlike many machinery parts, rubber items don't have the tell tale signs of quality to go off when considering if they are fit for purpose, it's just too hard to tell.

Bearings? if a standard size, I just get them cheap locally, skf, fag, ntn, nsk, any quality name should do.

 

[lone wolf]

Yea I understand this is the way to go I agree. Was just trying to get input from people that have personally tried the Chinese seals or bearings. I know of 1 guy that has used chinese seals in several saws. He says he has had no issues as long as care is taken during installation. I'm not condoning the use of Chinese parts by any means, I'm just curious

Yes I tried the bearings are junk forget it!

 

[trappermike]

Yes cheap bearings are not worth the money. But when ordering seals from a bearing supplier ALWAYS stipulate 2-lip seals,otherwise I always got single lip seals,which did not have the outer dust-seal lip,this second outer lip (like factory) does help crankcase sealing,but most important keeps dirt and sawdust from quickly wearing out the main seal lip.

 

[trappermike]

I usually order NTN bearings with the teflon cage,they do usually come with a seal on each side of the bearing,just pop out and discard these with the tip of a sharp knife,your bearings need the 2-stroke mix pouring thru them to cool and oil.

 

[trappermike]

The older type bearings are not desirable with a metal cage,it is almost always the metal cage that fails on these bearings,coming apart and twisted up,sending metal debris up the transfer ports and wrecking the piston and cylinder.
I actually found bearings that are all balls,no cage,much better strength ,capability and no cage failure issues,but not available in the smaller bearings saws use...bummer... I was shown one,they actually fracture and split the outer race,then spread it to get the balls in,really cool engineering.