A few years ago a customer's carburetors had a problem with the choke rods having too much friction and thus the choke plates were hanging partly deployed. On 80s Keihin carbs this is critical because their choke system plays a huge role in cold starting. I systematically chased down the problem. Bent choke rods? I see that often enough and can usually straighten them. Nope. Not it. After a few other checks I discovered by process of elimination that the problem was the lower steady plate. When I loosened the plate's screws, the choke system freed up and functioned normally. I confirmed it as a sure thing by installing a steady plate from another set of carbs. Success! The choke worked as it should, freely and without undue friction.

I am sure what caused the steady plates to bend is someone in the past damaged them when they diassembled or reassembled these carburetors. Like anything potentially delicate, the order in which parts are removed and replaced is important, and sometimes only experience keeps you out of trouble. Possibly even unusually rough removal from the engine could bend them, but I think it is mostly due to improper disassembly.

There still was a problem however. The customer would not believe that the choke system was so vulnerable that a misalignment in the carb bodies that was so small it couldn't be seen in the assembled carburetors would keep the chokes from working properly. But it did. It was confirmed real. And though it is rare, I have seen it a few times since. The day on which I write this in fact. On today's carbs, both the upper and lower steady plates are bent on these CB900F carburetors, and not just a little! Check it out.