EX500 bore spacing?

bladeracer · 07-22-2009, 4:45 AM

Anybody got an EX500 engine apart or know of one?
I'm trying to find out the bore spacing as I'm looking for a barrel to use on a different engine.
I need to know the distance between the cylinders (across the camchain tunnel), then I can add the 74mm bore to give me the spacing. Even an old head or base gasket would be near enough.
Thanks :-)

Twincam · 07-22-2009, 6:08 AM

I've got a GPZ500S/EX500, but its not in bits yet - give me a few years and it might be

Good Luck

bladeracer · 07-22-2009, 7:07 AM

Quote:

Originally Posted by Twincam

I've got a GPZ500S/EX500, but its not in bits yet - give me a few years and it might be

Good Luck

I'm not familiar with them at all and don't even know if they ever came to Australia.
Do they have parallel intake and/or exhaust ports?
If they do, probably a measurement of carb and/or header spacing would tell me if it's near enough to investigate further.
I was actually hoping the thread might catch the eye of somebody that's racing one as they're very common in the US :-)
I've ruled out nearly every parallel twin, centre camchain engine.
The only two I haven't gotten bore spacing for is the EX500 and the CB-Twins (500, 450, etc).
I'm building an XS400 engine but want bigger barrels. I was told yesterday that the XS650 bores are at 118mm which is only 2mm wider than the XS250/360/400. But they're very tall so there's a fair bit of milling involved to shorten them. The CB500T looks like a good bet but I'm still chasing a measurement on those. The DOHC head would be a bonus if it fits.
I may still end up just boring the XS400 barrels and re-sleeving them with plated aluminium liners just because there's likely to be less machine work involved. A mate has a shed full of XS650 stuff which I'll go through on the weekend so I'll hopefully have it all sorted soon :-)