Main Bearings Idenitification

[Thedktor]

Greetings,

If you follow the link below you will see that SH bearings are "Special Heat Treated",

http://www.koyo.com.br/upload/koyo/cat1 ... arings.pdf

Hugh.

Ah, that is very interesting thank you Hugh. Looks like the heat treated ones are not available through the usual internet sources though.

Suzuki £87 for the pair

Standard Koyo = about £20 for the pair.

I guess for normal use you would be unlucky to wear out a standard bearing, whereas the proper suzuki one would probably last 50k+ miles?

[Hugh]

Greetings again,

For my bearing supplies I use a very friendly and knowledgeable supplier here in Stockport, Emmett Enterprises, 0161 477 9020. I have spoken to one of the chaps there, Dean, and he tells me that at first checking he has found reference to KOYO 6303 SH49C4, but the available bearings are in stock in Portugal. Anyway he is going to make some further enquiries for you, so if you give him a call, perhaps later this afternoon, he will have the relevant advice, costing, etc. Mention my name when you call.

I could always pop in and post them on to you if that might help.

TTFN

Hugh.

[akendall1966]

Thanks all for the replies. i too have used Simply Bearings for many years as it happens, so I asked them the same question.

They had not seen an "SH" marking but also suggested C3 types are normally marked.

I'm sure two-strokes I've rebuilt in the past use C3 mains, maybe as they don't have a lot of oil sloshing around they get hotter?

I have seen C3 referenced for use in race engines where high revs for a long time = hot running; 2 stroke with minimal oil coiling makes sense to perhaps have more clearance to.

Good find from Hugh on the SH something new learned there for me.

[Thedktor]

Sorry for the slow reply, and thank you Hugh for your help and suggestions.

Interestingly the left bearing (stator/flywheel) has no extra markings so I ordered up another Koyo and got the same back. The right hand one marked SH is the primary drive side and takes all the load - I think to put aside any doubt it would be best just to get the OEM one....

20190524_065212.jpg (93.18 KiB) Viewed 1712 times

[mechanic]

The, special heat treated bearing really comes into its own when working in unfiltered or dirty oil, such as a sealed unit with a long service life like a gearbox. Hope this helps.,