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main bearing thickness

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95 xr600r

I hadpurchased a set of wiseco mains and they went in the cases fine. Upon case assembly, i noticed a gap that would not close. I removed and checked everything. But all was good. I then measured the thickness of the mains and compared to the stock. The one that came out was thinner. I forgot the numbers through the course of waiting for the new bearing. And was pissed enough to just slam it together without remeasuring and noting.

Anyways. Motors together.

I emailed wiseco and they said it mustave been a sellers error shipping me the wrong item. So id like to know, what is the thickness of the right side main bearing?

And has anyone experienced this as well?

Im gonna send a pic of the bearing to wiseco with my digi calipers in it so they can see. Id ship it to them physically,but emails free!

Thanks all!

EZ

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Interesting..I've just checked there website and they have no main bearings listed..Is the bike still together with this thinner bearing in place??..That R/H bearing needs to come from Honda ,, it'll always be wrong if it simply comes from a bearing shop..It's marked as a 6307 from bearing shops but it isn't a real 6307 unless it's a Honda 6307..The L/H main which is a 6308 is fine from a bearing shop,,right is not..Anyway..Can't get the measurements today as the bearings I have are in storage..I'll collect them tomorrow and have a gander with some calipers if no one gives you a measure first..

 

XL/XR600 use the same p/n's for left and right mains from 83-2k so if someone has  RH XL bearing it'll be the same measure as the RH XR..Just checked at ServiceHonda..all the same numbers..

Edited by Horri

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Thank you sir. It was a 6307 but a 6307C3...?? The wiseco guy said it should be a 6307. Its the same brand (koyo, i think) as stocks...buuuuttt...

So now Horri its a honda right side main and a wiseco left. Motors been together. Im just slow. Its not a priority. I dont expect a refind or anything. Just wanted to inform them so no one else goes through it. I mean if it was for a customer and i had to make them wait three more days itd be bad.

Ill post pics tomorrow of it...i may have one...

Thanks horri

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mmm..Well I'll be honest with you..I have 3 main bearings and none of the numbers really compute to me unless you maybe read them backwards :devil:

 

They are::

 

1,,TM-SCO736CS19..Numbers are as close as I can ascertain on that one,,It's an NTN bearing

 

2,,TM-SCO736..Also an NTN.

 

3,,,,Same as #2 so no point me adding it

 

Strange numbering..not sure what to make of it really..Yell if you want a measure of them..Pretty sure they're both the same ..

 

Odd really as those numbers sort of blow my 6307/6308 business..They're all original Honda bearings..I appear to have no supposed 6308s..or I suppose whatever they are in Honda OEM numbering...backwards,, :devil: ,,No idea really what it'd be,,836 maybe

 

What's the outside measurement on that one you posted above???,,just trying to make sure I actually have the correct bearings myself..Mine measure 80mm across the center..

Edited by Horri

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I had exactly the same issue, as per usual I went straight to a bearing shop to buy mine (much cheaper than honda) and like you the 6307 R/H bearing was too thick. So I bought some "XR600 main bearings" off ebay, when they arrived... the R/H was too thick. At this point I realised the honda one was actually special (well duh...).

 

So instead of spending a fortune on Honda ones I just bought SKF (the best IMO) and got it surface ground to the correct thickness at work. (yes I had the same amount off each side, yes I cleaned it ultrasonicly afterwards, and yes, the engine has been running fine for 2 years with no problems!) TBH it's prob just easier to buy the Honda one, but I'm a proper cheapskate (but a cheapskate with access to a precision machine shop!).

 

FYI the C3 is an industry specification for running clearence, C3 is quite loose for high speed/high temperature running, it has nothing to do with the special size.

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Just to be pedantic, C3 or other larger than normal clearances has nothing to do with bearing speeds. (a regular vs c3 with have the same max rpm spec)
C3 or more has to temperature difference between the inner ring and the outer. Usually a steel axle thru the inner ring and an aluminium house on the outer. 

Also certain sizes of bearings the clearance specs can overlap.  One can have a C3 that is in fact tighter than a CN (normal clearance) 

Anyway, Honda engineers are strange for making a special narrow 6307... 

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I learned a long time ago when rebuilding a Honda engine and replacing main bearings, ALWAYS use Honda bearings.  Honda does not use normal main bearings in their engines.  The numbers will be the same as a standard bearing but the Honda bearing will be slightly different.

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I learned a long time ago when rebuilding a Honda engine and replacing main bearings, ALWAYS use Honda bearings.  Honda does not use normal main bearings in their engines.  The numbers will be the same as a standard bearing but the Honda bearing will be slightly different.

 

Yes, Honda do often draw up a lot of their own bearings, Special cleances, groove geometry, ball size, cage material and type. Special heat treating and steel.. Usuall made by NTN or NSK.

However, on the XR600, the 6308C3 is nothing special and everyone has had no problem using off the shelf brands. 

On my 125 gp racer, the 6306 mains were special. You could not use over the counter C3 or even C4, the bearings would seize. A friend found this out in a painfull way at 150 km/h....

The only reasonable substitute were FAG 6306 TBP63 at $ 130 a piece! These were good as they acually gave up to 1 HP more on the dyno.

I think CW had some special ceramic bearing made up for that money unlimited bike....

 

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Whats the outside measurement on the one you posted above???,,just trying to make sure I actually have the correct bearings myself..Mine measure 80mm across the center..

Sorry Horri that ones the L/H one its inside now...

Heres the right side one i got from wiseco that was too thick

OD:80mm

ID:35mm

Thickness:21mm

Im betting the stocks like 18mm

Does nobody have an old Right side case main bearing to measure its thickness for me?

Id appreciate it greatly.

CAM00626.jpg

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mmm,,well those NTN::: TM-SCO736CS19 which I read as being the 6307s if you take 736 and go backwards and chuck a zero at it are

 

OD:80MM

ID; 35MM

Thickness 18mm..or close to it.

 

Dunno if that's any good to you but there it is..and gawd knows if that's the correct reading of the numbers,,Honda are plainly influenced by the :devil:  when it comes to bearing numbers..

Edited by Horri

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