AJS /Matchless 650 standard twin fitting CSR 8.5 pistons
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AJS /Matchless 650 standard twin fitting CSR 8.5 pistons
Has anyone fitted the higher compression pistons to the standard 650? Will the bottom end cope/ are the csr/ standard bottom end the same. Thanks in anticipation for any info.
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Re: AJS /Matchless 650 standard twin fitting CSR 8.5 pistons
No problem Steve. You have only to set the ignition at 34° instead of 39°according the owner's manual. You can swap the main jet 390 with a 450 one. But I don't think you want to ride your bike full throttle !
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Re: AJS /Matchless 650 standard twin fitting CSR 8.5 pistons
Thanks Jean-Noel for your reply and info, cheers Steve.
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Re: AJS /Matchless 650 standard twin fitting CSR 8.5 pistons
I thought the ignition timing is 35° (11/32) for all 650 models?
I was also told that 8.5 pistons are no longer available? I've no idea what's in mine but I intend to leave them well alone as they seem to be working well with minimum oil consumption and healthy compression.
I was also told that 8.5 pistons are no longer available? I've no idea what's in mine but I intend to leave them well alone as they seem to be working well with minimum oil consumption and healthy compression.
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Re: AJS /Matchless 650 standard twin fitting CSR 8.5 pistons
Sorry Steve ! Michael is right : the ignition timing is definitively 35° - 11/32 for all 650 (except if hi comp pistons, 10.25 ratio are fitted : 29°). 39° - 3/8° is only suitable for 500 & 600 twin. Checked in 62, 63, 64 owner's manuals, and workshop manual 57/64. And yes pistons 8.5 CR are unavailable from AMOC PARTS in Std, +0.20, +0.40, only +0.60.
Cheers. J.N.
Cheers. J.N.
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Re: AJS /Matchless 650 standard twin fitting CSR 8.5 pistons
Might just be worth checking Feked and also British Only Austria for 8.5s in the other + sizes. They seem to list them (JPs) and Feked's online shop says they have 'em (if you start to pretend to order some).
I've been running my Mod 31 with 8.5 +20 JPs - supplied in fact by T&L Engineering - for a good few years without problems on a new Club crank and some Thunder rods.
But STD 72mm, not shown anywhere I can see.
I've been running my Mod 31 with 8.5 +20 JPs - supplied in fact by T&L Engineering - for a good few years without problems on a new Club crank and some Thunder rods.
But STD 72mm, not shown anywhere I can see.
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Re: AJS /Matchless 650 standard twin fitting CSR 8.5 pistons
Thanks for your help, much appreciated .