Topic: CB400F carb adjuster springs

[MetricMotowerks]

Hello,

I'm working on a 75' 400F and am having an sync issue when returning to idle. The issue is that the carbs return out of sync, but a few taps around the adjusters bring them back to pretty close. As a test I've synced them at 2k rpm and things are good once on throttle so I'm thinking that the springs under the caps on the adjusters aren't doing the job anymore. I was wondering if anyone 1. has dealth with this issue 2. has found a reliable replacement option.

Any help is always appreciated! Thanks everyone.

[Alaxy Galaxy]

There are no individual return springs on the stock CB400F carbs. The only return spring is the big one with a plastic sleeve on the exterior of the carb bodies. The springs that are on the pivots under the caps only help to locate the rod in the center of the slides.

Syncing these carbs is generally done at idle.

[MetricMotowerks]

There are no individual return springs on the stock CB400F carbs. The only return spring is the big one with a plastic sleeve on the exterior of the carb bodies. The springs that are on the pivots under the caps only help to locate the rod in the center of the slides.

Syncing these carbs is generally done at idle.

Yep, that is the issue. The adjusters became a little "twisted" when closing, after blipping the throttle, and they hung up on the edge of the pivot ball. It was causing the slde to stay open a few mm's. They would settle if I tapped on them so I stretched the springs in order to help keep them in place. I just couldn't figure out what was causing it to happen in the first place.

[Flyin900]

Pictures please of the whole carb setup? Do you have the two shaped metal discs that join the syncing screw sets together installed on the top towers between 1-2 and 3-4 carb sets?