Bearing Question

[oldjapanesebikes]

A question for the engine experts.

On the GT550 there is a discontinued bearing used on the crankshaft with Suzuki part number 09269-25010. Its a Koyo, and the only marking I can see on it is 83563-9. I have asked Suzuki (can't help me) and Koyo who tell me its a specific Suzuki bearing which Suzuki hasn't ordered from them for at least a couple of years.

Koyo is still checking to see what is special about this bearing and may still get back to me with an alternate, but I was wondering if anyone out there had already figured out a cross to another bearing ? I don't need one right now - just planning for the future.

Thanks !

[tz375]

Crankshaft bearings are usually a looser C3 clearance than normal bearings.

One way to replace them is to measure them up and find a common bearing with the same ID and width and make up an outer sleeve to take it out to the stock crankcase size.

[Wayne Meuir]

If it is the same situation that exists on the GT750, there is one crank bearing with a locating groove ground into it. That bearing is NLA. When I did my GT750, even Paul Miller did not have one. It is the same bearing as the other three, just that it needs the locating groove. I bought 4 of the regular bearings and had the groove ground into one of them and it is working fine.

Wayne

[oldjapanesebikes]

Crankshaft bearings are usually a looser C3 clearance than normal bearings.

One way to replace them is to measure them up and find a common bearing with the same ID and width and make up an outer sleeve to take it out to the stock crankcase size.

Thanks - and also thank you Wayne - I'll do some more checking. I'm in the process of pulling apart a scrap crankshaft just to see exactly what the differences are. There are two other bearings with different part numbers also used on the crank - one of them with part number 09262-25036 has a groove and one less ball in the race, but otherwise measures the same and is still available, and I sill have to check the other one which is 09262-25034 and also still available. I suspect I may be able to use the second one as a substitute if required but will have a better idea once I have it off the crank.

I'll let you know what I find out.

[H2RICK]

Crankshaft bearings are usually a looser C3 clearance than normal bearings.

Ya know, TZ, that's a thing that has puzzled me for years. My first teardown of a totally stock, never-molested H2A engine had a C3 clearance bearing on the output end of the crank. I thought to myself "No wonder these things rattle so much!!".....but I replaced it with the same tolerance bearing because I figured Ma Kaw knew better than me. Still running with no probs so I made the right decision.
My current rebuild had a C4 tolerance bearing in the same place on the crank but this engine has an unknown history.....so all bets are off as to the originality of that bearing. I've replaced it with a bearing with the same tolerance but now I'm wondering if that was the correct decision. I wouldn't want to pound out the outer bearing fit in the cases or wreck my primary drive gear and/or clutch basket ring gear. Any thoughts on this ???

[oldjapanesebikes]

I have heard back from Koyo, and they also sent me a pdf file showing what is special about the 83563-9 supplied bearing under Suzuki part number 09269-25010. As tz375 commented, it is a C3 fit, and as per Koyo is just a standard 6305 bearing with two modifications - the addition of a rolled steel locator pin, and also the addition of a collar.

A link to the pdf file is here if anyone wishes to download the document.

I suspect that if you had access to a machine shop to bore the hole for the locator pin, this would be simple to duplicate. As I look at the other bearings used on the crankshaft, the addition of the locator pin for each one seems to be the only major change made to what is otherwise a standard 6305 bearing worth between $10 and $20 retail depending on whether it is ordered with a circlip groove. For example, the bearing on the right end of the crank, part 09262-25036 (marked as 83580) is likewise a 6305 bearing with a circlip groove, which is a standard bearing, to which a locator pin has been added.

[oldjapanesebikes]

Just wanted to give an update on this topic - I now have a quote from Koyo about supplying this Suzuki bearing part number 09269-25010 (which is a Koyo part 83563-9C3), and believe it or not, they are willing to sell me this bearing directly. Of course there is one small snag - I'd have to buy 80 of them.

Any thoughts from anyone how much demand for this bearing there would be amid the GT550 community ?

[H2RICK]

Hmmmm....apparently that bearing fits ONLY the 550 and nothing else.
You might be awhile selling 79 of them, Ian. Actually I'm surprised they were willing to sell such a small quantity. Maybe the economy in Japan is worse than reported.....
Since Koyo is willing to sell them AT ALL means they now have permission from Suzuki to release that bearing design for general sale.
Gosh....only 30 years after the last time Suzuki bought any from Koyo.....
How generous of Suzuki !!!
Pettiness like this makes me really upset with big corporations. Grrrrrr......

[oldjapanesebikes]

That's correct Rick - these only fit GT550 Suzy's.

As each crankshaft uses as many as three of them, I suppose the other way to look at it, is its 26 GT550 crankshafts globally. And they are definitely hard to find - a set of three of these bearings went for almost $400 CDN recently on fleabay.

Of course, the con rods aren't available from Suzuki any more either .............

[H2RICK]

Hmmm....I wonder if there are 26 GT550 cranks needing rebuilds out there somewhere ??? Doubtful....but one never know, do one ??!!
I wonder if SEP in the UK might have those bearings in stock ???

[redroadster]

Hi, I am looking for one of these bearings, did you get anywhere with findind an alternative supplier or bearing?

[oldjapanesebikes]

For a GT550 ? Sorry - no. I still have the quote, but of course it is out of date now and I sort of doubt prices have gone down You don't say which bearing it is, so assuming that it isn't one still available from Suzuki (which would be 09269-25010 - the others are still available), then your best option may be to have one made if you can't get one from fleabay, Reiner (his email is GTReiner1@aol.com), Marcel (I recommend both highly, but prices are in Euros and shipping will cost you) or PM (and folks have had mixed luck with him - as have I). If you do decide to have one made, and if you are in the USA, then give someone like Bill Bune a call to see what he can do. If you live elsewhere, then you will have to check around.

Good luck !

[redroadster]

Thanks, I live in the UK, Yes it is the one that is discontinued but I have had some luck though, a company called Grampian Motors in Liverpool UK, specialize in engine rebuilds, I gave them the information and they have supplied me with a Koyo 6305 c3. with the locating pin for £17 which is about $26. Apparently it is the same as fitted to a Yamaha LC350. I received it today and its now fitted. I have now had the crankcases shot blasted, I am thinking of giving them a coat of clear laquer before reassembly

[dinogt]

I just look this post, have you any pics and dimentions of this bearing ?
C4 is for a motor witch goes over 11000rpm and we must not mix C3 and C4 on the same crankshaft.... the bore between a KOYO,TNT, SKF ... can be different so a C4 made X can have the same bore than a N3 made Y, so , don't mix the mades
To stop a bearing turning on himself) we can also do with an O ring instead a pin , for 350 rz and Banshee hot rod or Wiseco have those bearings with o ring at the middle
Attention: it seam to me that on the 350rz and the 250 RS Aprilia the ring bearing is not exactly at the same place

[oldjapanesebikes]

dinogt - I had included a link to the document Koyo sent me further up the page - here it is again. I had a few other emails from Koyo in Japan as well which talked a bit about the fit (C3) and about the oil slinger collar that fits into the side.