Re: Hello & Information on Peter Green Porting

Posted by hendred on Oct 24, 2022; 1:25pm
URL: http://silk-motorcycles.221.s1.nabble.com/Hello-Information-on-Peter-Green-Porting-tp5002432p5002435.html

Hello Shaun and Nick

Peter Green porting was used on later bikes.  If you use the search function you will find reference to it but not details of what it entails.  I believe it is position and sizing of the ports in the barrel.  The pistons didn't change.  Regarding performance with the 38mm carb, check the slide is opening fully when the twist grip is wide open.  I found my mine wasn't opening fully - again you will find a topic on it in using the search function.  Another owner and I found that if you time the Lumenition system statically and then check it with a strobe it is 2-3 degrees retarded.  Probably due to wear in the advance/retard mechanism.  Setting the ignition to correct for this made a big difference to performance.  My handbook says 0.2" or 5mm static advance.
My Silk is pretty docile up to 4000rpm and then takes off from there - not quite what the literature of the time says about low speed torque!

Hope this helps.