itsascrewdriver Posted November 10, 2022 Report Share Posted November 10, 2022 Hi there, I'm currently building a 421 4 mil and I'm hoping someone can point me to a good starting point set of jets since I've never run a Keihin carb before. I'm in Utah and most riding is done around 4500-5000 ft above sea level I'll be running Keihin PWK 35mm carbs, K&N pod filters, VForce4 reeds, SLP in frame pipes, cool head with 21cc domes, and 4 degree timing advance. From the What Jets are you running sticky I found a likely seeming setup posted by Handyman that's using 155 mains with 48 pilots, I was thinking of starting a little richer and doing chops to tune it in. Any advice would be appreciated Thanks 🙂 Quote Link to comment Share on other sites More sharing options...
dano3 Posted November 11, 2022 Report Share Posted November 11, 2022 Redline serval with same mods except i run shearers and depending on temp at 1000ft above sea level I range from 148-158M and 42-48P with a CEL needle. Start rich and work your way down slowly. I followed that duncan racing jetting PDF to get pilots close when I first put it together. Also, ask your builder???? Quote Link to comment Share on other sites More sharing options...
itsascrewdriver Posted November 17, 2022 Author Report Share Posted November 17, 2022 Unfortunately I'm my builder, so asking me isn't a great option. /s Thanks for the info on what you're running though. Quote Link to comment Share on other sites More sharing options...
dano3 Posted November 18, 2022 Report Share Posted November 18, 2022 3 hours ago, itsascrewdriver said: Unfortunately I'm my builder, so asking me isn't a great option. /s Thanks for the info on what you're running though. Who is porting cylinders and cutting domes for you? Ask them Quote Link to comment Share on other sites More sharing options...
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