Weird, i was just talking about this. I run 28s on a 421 serval and they are dialed in with the Snipers from Cam himself. He did have trouble with these carbs air screw adjustment. I have switched to Shearers and i cant get the jetting where i want them. I just bought 33 PWK from a guy running Driveline set up who couldnt get his 28s working either. This guy eneded up going 35s.
Driveline seem to perfer 35s on their 421s, thats how id go.
Yes, you can buy just one lever, what ever the side. I bought StreamLine "Reflex" shorty levers years ago, they run great. I had to make a new "link" when i did the yfz conversion 'cause the brakes levers were not compatible. Envoyé de mon SM-N975W en utilisant Tapatalk