I'm about to start my build so it'll be ready for next summer, but I'm trying to cheat and not have to change the jets a couple times. I live at about 2000 ft in elevation, and I'm also installing velocity stacks and exhaust. Any recommendations on jet sizes for all circuits? Thanks, brothers and sisters!😁
P.S. - And does anyone have dyno numbers on an 1100 with TJ's Max Performance set-up?
@KSquared you can't cheat dude. Thats bullshit. This is part of tuning. if you dont want to do it, take it to a shop to do it for you. There are no shortcuts. dyno ghraphs will be available on the site when we are done testing.
You can’t cheat carb work. @TJ is right about that. If you rush it or cut corners, the bike will let you know. You can get close, but you still have to ride it and make changes. It will lie to you unless that bitch is all hot-n-bothered. Only then will it be truthful about what it really needs. And don’t start tearing it down and tossing jets into a Cool Whip container like it's just a bunch of loose nuts and bolts that you will never use, but will keep for decades in the garage. That’s how parts get mixed up and headaches start.
Pull one jet at a time. Clean it. Read the size stamped on it or measure it if you have to. Then put it in a small bag and label it — front main, rear pilot, whatever it is. Keep everything separate and organized. Damnit Cinderella clean that muthafuka!
Inspect the new needles in your kit before you install them. Look for part numbers. Measure them if you can. Write that information down. That gives you a solid comparison point between what came out and what’s going in. When you you make these changes, you’re changing how the engine breathes. Knowing your old needle and your new needle helps you understand what the kit is trying to accomplish and what those intake and exhaust changes should be doing to your mixture.
At 2,000 feet you’ve got a little less air than sea level (about 6% less). That usually means you’ll end up one size smaller on the main jet compared to a sea-level setup. The needle may need to be lowered a touch (clip up) to lean the midrange (25-75% of the throttle range). The pilot jet usually stays close to stock. But pipes, air filter, baffles, and whether someone’s drilled the slides all change the outcome. There’s no universal magic number.
Before you even start the rebuild, measure the new jets and write down the sizes. Order two additional sizes up (+1 and +2) and two sizes down (-1 and -2). Kindergarden math finally pays off here. Grab a set of .020 inch needle shims while you’re at it (I usually grab 2-3 sets cause I have big...hands). That way when you test ride and feel how it responds, you’ve got options sitting in your toolbox instead of waiting on more brass.
Carb tuning isn’t black magic. It’s clean parts, good notes, and micro adjustments. Take your time, pay attention, and let the bike tell you what it wants.
@NotChuckNorris outstanding post my man!!! thank you!
