The air screw is actually a volume control screw on the CV carb. Clockwise leans it; counterclockwise enriches. I'm still on a 15 pilot with partial free flow exhaust. It takes just a little bit turning the VC screw to get the idle to change. Not much at all. Starting from 2 to 3 full turns out is a good start point. Make sure the bike is warmed up. Search on in the general gallery for a few data sheets on the BS29 I found. I like the one below
Agreed about your air screw. Better to run a little richer than leaner - Screw that baby all the way in and back it out 2 full turns.Your carb may have a lot more thread than mine, but I don't believe there is even enough room to wind it out 4 turns on a PWK.
Even I faced similar issues with BS29 when I had it in my bike. 17.5 pilot was good but it was a bit too rich. I did put the needle back in 2nd notch with the 17,5 pilot and it worked pretty well.. better than 17.5 in lowest notch.
Not real familiar with that carb, but screwing the air screw in should make it richer. I'd try two or three turns out from the stop and see wht that does. You're too lean as it is. Bare
Happy new year to all bull riders out there!Despite different combinations of pilot jet/main jet/needle positions(UCAL BS29 carb), my bike seems to pop horrendously. Right now the main jet s 120, pilot is 15 and needle raised one notch.Air screw is about 4 turns out - the bike doesnt pull well at all.Its a goldstar exhaust and a DU100 K&N air filter in the stock air box.No air leaks in the intake or exhaust routes.I had tried a 17.5 pilot before this but then the plug goes sooty.Another question is: During tuning the air screw, I try to open up the air screw to get to the point where the RPM reaches the peak and then drops, this point never seem to show up at all!Any ideas why this is so? Perplexed, annoyed and fingers crossed Thanks guys!Sudhir
Are you on the stock air filter?
I have the stock air box on an Electra, but am using a k&n filter. I just moved the needle one notch, and sometimes I get a little popping when downshifting. But it pulls nicely and starts fine. I'm still dialing things in. With that said, I've been thinking about the 30mm performance carb from our hosts.... Good luck on your freeway run. I remember reading somewhere that our stock carb has a lot of potential to perform well.While it might be true, its definitely a test of patience!
After much back & forth (I probably had the carb off & on a dozen times dialing it in) I'm back to the stock 15 Pilot & the stock 110 Main with the needle lifted two shims. My needle has the permanent plastic collar on it over the notches so I can't talk notches with you. My mixture screw is about 1 1/2 turns out. The bike runs perfectly set up this way & now has 600 miles. It kick starts under all conditions with one or two kicks (I never use the ES) & never dies at stop signs or pops or sputters or any other bad stuff. It pulls well in the first 4 gears up to my break-in speeds. I've only even been in 5th a couple times on flat stretches. PS: Did your needle have the plastic collar on it when you first took the carb apart?I wish now I had broken it off Day One & dialed it in using the notches.Geo
Thanks Geo. Mine does have a plastic ring below the notches but i can adjust the circlip position(3 notches).I would love to hear if you all have this same throttle response or does it mean i need to fine tune the carb?
I put on a 17.5 pilot, put the needle on its leanest notch(first from the top) and set out to check the bike.There seems to be good improvement throughout the range. Popping still present but at least the bike runs good. However, there isn't the crispness i am looking for. Usually I would expect the bike to surge ahead with a good twist of throttle in the 3rd gear. It gets there but in a very gradual manner.