I have an OS 91FX ring. I notice now there is an ABC version out, with as far as I can see the sams performance.
Is there any difference?

thanks,
Leonard

I hadn't heard that. Where did you get that info. The OS 91FX has a ABN liner I believe. OS hasn't used ABC in quite awhile. Even their ringless engines use ABN.

I have only seen it in modelling magazine ads here in the UK. The guys who put the price lists together in these ads are not always accurate, so they could well mean ABN.
However, I have seen this several times and so assume there is now a ringless 91FX.

Is this correct?

Leonard

I think you've been misled. There is no 91FX ABC or ABN version they are all ringed. Ususally engines of this size and larger are ringed otherwise the compression would make them hard to start. I think Jett is the only maker of a true (nonringed) ABC 90 size engine.