When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey I've got a 79 80"Flh - the carb rebuild kit came with 2 needles one has a spring loaded tit the other is flat on top like the one that came out --which one is best to use-- Keihin butterfly carb
thanks
I have used both.... the spring loaded needle is a way to maintain a constant pressure on the needle tip therefore is supposedly easier on the tip and makes the tip last longer. It allows the float to bounce while riding so you have a compliant needle and seat interface. The solid is just that a solid tip that when the float drops it lets fuel in and when it presses against the seat it shuts the fuel off. You can imagine the solid needle and seat sees more frequent open close action than the spring loaded needle. You can also assume the tip of the needle is seeing more bounce time on the seat.
SOme have trouble getting the spring loaded needle float height. I usually tip the carb asm on its side and set tab to proper float height. Then to be sure I nailed it I hold the bowl asm against the bottom of the carb, turn the fuel on and of then drop bowl down to see where fuel level is in the bowl. I have also said screw it after the bike will not idle on the jiffy stand without spitting and sputtering and replaced the spring loaded needle with the solid.
My '81 FXB is currently running the spring loaded needle
The original one was superseded by the spring loaded one for reasons - the rebuild kit has more then one extra piece as they made 1/2 dozed different ones over the few years
The 4-sided spring loaded one is for a CV carb and is an upgrade in a butterfly. Setting the float level with a spring loaded needle valve requires the carburetor to be tilted to a certain angle. Follow these instructions:
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.
Float valve
