Needle Size

[mcncoic]

Here is a question that I have not been able to find an answer to on the site. I am starting to rejet my stock carbs for pipes and filter mod. I have read just about every article about jetting and think I got a pretty good idea where to start at. With going from stock jetting 200 mains to say 280-350 (for example) will the factory needle still work or will I have to get a larger one?

 

The pipes I got from a friend (FMF Fatty) the silencers need to be repacked. The K&N got off ebay but no jets. I have seen jet kits come with needles so this is why I ask. I don't plan on buying a kit just the jets (mains&pilot). Any help?

[Ducman]

Custom tapered needles do make a difference on the needle jet circut, change the rate at which the needle lets fuel in the carb, usually the same as stock at 1/4 throttle but let more fuel in than stock progressively from 1/4 to 3/4. Kind of runs like it is on the stock clip at 1/4 throttle and 1 clip richer by 3/4 throttle if I understand how it works correctly. You don't need them, stock is fine.

 

Heres my jetting recommendations for your pipes and filter at sea level, 60 to 80 deg. air box lid off:

 

#30 pilot, air screws 2.0 turns out

needle in stock position (3rd clip from blunt end)

#330 mains

 

Due a plug chop to verify mains, start at #330, and tune airscrews to shees likings