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Main Area => General GS500 Discussion => Topic started by: ausgixxerpilot on July 19, 2009, 06:46:30 AM

Title: GS500 Bore Spacing?
Post by: ausgixxerpilot on July 19, 2009, 06:46:30 AM
Hi,
I'm trying to find out the bore spacing of the GS500 engine.
Would anybody happen to have a head or base gasket handy they could measure or scan for me?
I really just need the distance between the bores so I can add the 74mm bore to give me the bore spacing.
Thanks :-)
Title: Re: GS500 Bore Spacing?
Post by: cboling on July 19, 2009, 07:46:50 AM
I measured my old gasket and it came out at 1.03" or 26.162mm

Title: Re: GS500 Bore Spacing?
Post by: ausgixxerpilot on July 21, 2009, 03:49:37 AM
Quote from: cboling on July 19, 2009, 07:46:50 AM
I measured my old gasket and it came out at 1.03" or 26.162mm

Thanks heaps for that.
Are the holes of the gasket 74mm or bigger?
Either way it's not much more than 100mm bore centres which isn't going to work for me unfortunately.
Thanks again.
Title: Re: GS500 Bore Spacing?
Post by: Dr.Sparkie on July 21, 2009, 08:34:51 AM
the bore holes arent much larger than 74mm
Title: Re: GS500 Bore Spacing?
Post by: ausgixxerpilot on July 21, 2009, 08:47:25 AM
Quote from: Dr.Sparkie on July 21, 2009, 08:34:51 AM
the bore holes arent much larger than 74mm

Cool. So for future reference I guess it's 100mm.
Unfortunately I'm chasing barrels at around 116mm centres to put on an XS400 bottom end.
I've found out that the XS650 is around 118mm which is usable (I can bore it off-centre anyway before sleeving it) but I'm still trying to find a measurement for the GS450.
Thanks again :-)
Title: Re: GS500 Bore Spacing?
Post by: dgyver on July 21, 2009, 09:54:04 AM
The GS500 and GS450 have the same cylinder center spacing. The crank shafts are interchangeable.
Title: Re: GS500 Bore Spacing?
Post by: ausgixxerpilot on July 21, 2009, 10:31:34 AM
Quote from: dgyver on July 21, 2009, 09:54:04 AM
The GS500 and GS450 have the same cylinder center spacing. The crank shafts are interchangeable.

Thanks heaps for that, very good to know.
It hadn't occured to me that the GS500 uses the same bottom end as the original GS twins :-)
Looks like the XS650 barrel is the way to go then. It's near enough that it's definately worth grabbing one off Ebay for a closer look at least.
Only other ones left that might work are the EX500 and the CB500 now.
The KZ440 is another one I'm chasing a measurement on but it's only viable if it's got a fair bit of meat in the barrels for re-sleeving.
Thanks again.
Title: Re: GS500 Bore Spacing?
Post by: ausgixxerpilot on July 28, 2009, 04:18:40 AM
Quote from: ausgixxerpilot on July 21, 2009, 03:49:37 AM
Quote from: cboling on July 19, 2009, 07:46:50 AM
I measured my old gasket and it came out at 1.03" or 26.162mm

Thanks heaps for that.
Are the holes of the gasket 74mm or bigger?
Either way it's not much more than 100mm bore centres which isn't going to work for me unfortunately.
Thanks again.

Damn.
I've just been advised the GS500 bore spacing is 120mm so now I don't know who to believe :-)
I've also discovered the XS650 and CB500T are also 120mm so maybe a GS500 head on an XS650 is a future project :-)
Title: Re: GS500 Bore Spacing?
Post by: dgyver on July 28, 2009, 08:04:30 AM
If I remember, I will measure it later this week for you.
Title: Re: GS500 Bore Spacing?
Post by: ausgixxerpilot on July 28, 2009, 08:34:05 AM
Quote from: dgyver on July 28, 2009, 08:04:30 AM
If I remember, I will measure it later this week for you.

That would be very much appreciated :-)
Title: Re: GS500 Bore Spacing?
Post by: dgyver on July 30, 2009, 04:28:37 PM
Just measured a crank shaft... 120mm centers.
Title: Re: GS500 Bore Spacing?
Post by: ausgixxerpilot on July 30, 2009, 09:19:04 PM
Quote from: dgyver on July 30, 2009, 04:28:37 PM
Just measured a crank shaft... 120mm centers.


Very much appreciated :-)
I am still confused about the first figure from cboling though since he actually measured his gasket.
Are old and new GS500's the same?
Title: Re: GS500 Bore Spacing?
Post by: cboling on July 30, 2009, 09:38:32 PM
do you want the spacing between each cylinder (wall to wall) or the center spacing of the gasket. My mistake. I took the measurement of the space between. I can re-do in the morning.
Title: Re: GS500 Bore Spacing?
Post by: ausgixxerpilot on July 30, 2009, 09:47:05 PM
Quote from: cboling on July 30, 2009, 09:38:32 PM
do you want the spacing between each cylinder (wall to wall) or the center spacing of the gasket. My mistake. I took the measurement of the space between. I can re-do in the morning.

I want the bore centres but measuring the distance between the bores is fine as you just add a bore diameter to it to give you the bore centres.