OzVMX Forum

Clubroom => Tech Talk => Topic started by: Paul Jeffs on December 29, 2012, 03:26:18 pm

Title: 76 rm125a cylinder
Post by: Paul Jeffs on December 29, 2012, 03:26:18 pm
Hi
I am looking for a cylinder for my rm125 a and have been offered one that looks visually the same from a photo. Only problem is he claims the bore is 55.5 mm. As the stock bore is 56mm I'm guessing it's off a b model. I've asked him to double check his size and he still gets 55.5. Other than the bore and stroke what if any differences visually are there between the two. Thanks Paul
Title: Re: 76 rm125a cylinder
Post by: John Orchard on December 29, 2012, 04:39:08 pm
If the barrel has an un-bridged inlet port, and T shaped exhaust port it is an A barrel.  I just sold an RM100B barrel (RM100B & RM125A both have 50mm stroke so same port timing) that was a hint under 56.00mm, the 100B's still had 123cc cast into it; Suzuki must have used the same mould for both bikes but pressed in a smaller ID liner for the 100B.
Title: Re: 76 rm125a cylinder
Post by: Paul Jeffs on December 29, 2012, 04:54:16 pm
Thanks for the info John . The inlet port is bridged and exhaust ports square so it must be a B barrel. Thanks again for your help. Paul