Carburetor replacement upgrade suggestions desired

Stock 1982 KZ1100...considering to replace the BS34's with a Mikuni Flatslide or Roundslide carb set.
Which would be the best choice (and size) for my application? I want to retain the use of the carb boots/stock air box.

I've devised a method which replaces the stock air box snorkel/cover, and significantly increases air flow through the stock (or K&N air filter), with minimal sacrifice of engine protection offered by the original air box design. This simple change-over has provided a significant improvement (see pic) in the performance (and smoothness) of my engine, so I might like to go another step further.

The answer to that question depends in part on your goals and your budget. What are you trying to gain by changing the carbs?

You say that the airbox mod has increased power and smoothness. Have you actually tested this (dyno or timing lights) or is this just a seat-of-the-pants assessment? The mod should have no affect on smoothness, that is usually a function of balance and tuning. The increased noise can be deceiving.

Increasing air intake capacity and adding larger carbs can be steps toward increased power, but very little will be gained without changes to the exhaust system and ultimately cams and ports. The effect of such mods will be limited by the weakest link, the most restrictive part of the system. Getting the combination right is what leads to nirvana, and the right combo is dictated by the ultimate goal - fuel mileage - drag racing - road racing - touring - hot rod street bike - et cetera.

Thanks TexasKZ,

I'm aiming high, with interest in attaining the most performance without modifying the engine.
No cams, exhaust header, porting, etc.
The bike runs (and handles) awesome at this point, but would not a refined carburetor choice be better than the stock supplied BS34's, if available?

I did have one dyno-test run with (and without) the modified intake. The test did not show any horsepower change, either way. It did indicate the bike needed carb tuning though.

But, regarding the seat of the pants feel...It is smoother, perhaps because more air is available (making it easier for the engine to breathe), by removing the flow restriction before the air filter. Isn't that the purpose for using pod-filters?

Nirvana, YES!!!

"by removing the flow restriction before the air filter. Isn't that the purpose for using pod-filters?"


Yes it is and if you want to read several hundred (maybe thousand) posts, you will see that getting the carbs set up properly with pod filters can be a real pain. A stock or slightly modded air box is the way to go. With stock everything else, I'd be surprised if there was any measurable difference between properly set up BS34s and a set (pretty expensive) of more modern carbs. Seriously, there are a bunch of threads on this subject. You might want to use the search function on the forum to get an idea of what folks here have encountered.

I would consider this air box modification a slight one, tackling the two bird/stone thing.
Add the value of utilizing the plenum-type design incorporated into the stock air box, and the inherent protection of the intake system from the elements.

Here's two pictures of the production-unit I've had on my bike since September. The prototype pic. was prior to slight design modifications and laser graphic.

I don't have much tied up in development, and figure less than $20 retail, as long as my small first batch lasts.

Thanks for the suggestion on the carburetors, which I will heed...for now.