ba_da_bing Posted February 5, 2015 Report Posted February 5, 2015 (edited) Hey guys! I just purchased a 421 and currently the only set of carbs I have is a set of PJ 34mm alcohol carbs. Do you think these will perform well or would it be a waste of time trying to use them? Guys around here are telling me 35 or 39 PWKs... If so, what's a good starting point for jetting at sea level with shearer sb/sf oof pipes? Thanks Edited February 5, 2015 by ba_da_bing Quote
trickedcarbine Posted February 5, 2015 Report Posted February 5, 2015 34's could suffice. I would run them and if you're not happy try the 39's. Not worth the chunk of change going from 34mm to 35mm. Plus the cost to convert to alky on another set of carbs. Quote
ba_da_bing Posted February 5, 2015 Author Report Posted February 5, 2015 That's what I was thinking but some guys live and die by the 35 and 39 over a 34 or 38. Thanks Quote
ba_da_bing Posted February 5, 2015 Author Report Posted February 5, 2015 That's what I was thinking but some guys live and die by the 35 and 39 over a 34 or 38. Thanks 1 Quote
5150banshee Posted February 5, 2015 Report Posted February 5, 2015 I have run 35 pwk on my 421 and also 39 and like the 39 by far if your gonna make the change I'd just go 39 and if running alky have them taken to 41 or 40.5 whatever it is. Quote
Nightmare Posted February 5, 2015 Report Posted February 5, 2015 I like the 39's I have on my cub. 1 Quote
ba_da_bing Posted February 5, 2015 Author Report Posted February 5, 2015 Thanks guys! I may just go ahead and get some 39s that a local guy has for sale. BTW what would be the most noticeable performance difference between 35 and 39 own alcohol? Quote
sleeper06 Posted February 5, 2015 Report Posted February 5, 2015 39 pwk ,is the 421 drag ported and what type of racing do u do, it will depend how I would set carbs up Quote
ba_da_bing Posted February 6, 2015 Author Report Posted February 6, 2015 Sleeper06, Yes it has a HJR drag port. Mainly used for 300ft drags. Quote
sleeper06 Posted February 6, 2015 Report Posted February 6, 2015 One of my drag ported Cubs dialed in at 122.5 dumps /mains,55 pilot ee series needle 2 nd clip. Modified pilot circuit , one float cut off , big ass bowls . Now this is a 1/4 mile bike I would def call hjr to see how he would set it up Quote
ba_da_bing Posted February 6, 2015 Author Report Posted February 6, 2015 Ok. I went ahead and bought the 39's last night. Is it really necessary to have aftermarket bowls when running 39s on a 421? Quote
sprinklerman Posted February 6, 2015 Report Posted February 6, 2015 On alky, yes. I wouldn't risk it. Buy the MATTOON billet bowls. I've had the best success with them ,over others Quote
n2otoofast4u Posted February 6, 2015 Report Posted February 6, 2015 Thanks guys! I may just go ahead and get some 39s that a local guy has for sale. BTW what would be the most noticeable performance difference between 35 and 39 own alcohol? Be careful buying used PWKs. If they are drilled too damn much (like most do) its a CS to get new dumps put in them. Quote
slobanshee Posted February 7, 2015 Report Posted February 7, 2015 Got two 4 mill Cubs at 900ft above sea level. .122 mains/dumps. 60 pilots. EGL needle in middle. Does well for 300ft sand drags Quote
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