Yamaha owner seeking advice

[a100man]

Hi all

Fisrt of all apologies for crashing your forum..  I'm currently working on a Yam XJ550 and seeking to put a xj600 engine in it. The engine I have though would benefit from a rebore and that's where I hope you can help..

The bore of the XJ600 is 58.5mm same as the CB550 I understand. Problem with the XJ though is a complete lack of o/s pistons. I'm looking for a 59mm or thereabouts  - the XJ uses a 15mm pin and from top of the gudgeon pin hole to the deck is 17mm and to the crown is 25mm close as dammit. Do Honda suppliers have anything close ? Even a new set of standard rings for the Yam is going to be about 150 quid.

Anyhow hope you guys might (through gritted teeth) have something to offer a beleagued Jap owner,

Cheers

James

[matthewmosse]

I wonder if yam xs250 pistons might fit? Principally as I have 7 in the shed. I'll take a look as I have severeral sets of pistons out of things lying around,  might find something.

[Bryanj]

Only other thing I can suggest is try Wiseco in the US as they do lots of big bore kits for bikes

[a100man]

I wonder if yam xs250 pistons might fit? Principally as I have 7 in the shed. I'll take a look as I have severeral sets of pistons out of things lying around,  might find something.

A quick google suggests these are 55 or 56 mm bore - thanks for the suggestion though..

[a100man]

Only other thing I can suggest is try Wiseco in the US as they do lots of big bore kits for bikes

Thanks - I looked on there site and it's not that easy to decipher - had hoped you guys had a regular source for o/s 550 pistons for rebores.

[Bryanj]

I do, my lockup! but finding, or rather the time to go look and measure is not easy mate

[paul G]

Try IMD pistons they have a web site or give him a ring very helpfull.

[a100man]

I do, my lockup! but finding, or rather the time to go look and measure is not easy mate

Understood ! As it goes I have found some NOS rings in the USA which I bought (relatively) cheaply - however if they don't do the trick and I get some low compression figures I'll be back on the case. Thanks to all for your support.

Best

James