Removed exhaust to clean now idle is rough

Hey,

This is my first post, and just want everybody to know this site has been a god send.

I removed my stock exhaust from my 1978 KZ400B to clean almost 40 years of baked on chain lube and now the bike does not idle as smooth. The tach will fluctuate between 1200rpm to about 700rpm and occasionally dies. I did notice when removing the exhaust pipe holder and split keeper weren't tight, and the gasket looked a little worn out. When I reinstalled i tightened everything, so maybe this is my issue? Any advice would be greatly appreciated.

Welcome. Did you touch anything else? Pics?
Steve

I doubt removing and replacing the exhaust caused the issue.

Did you replace the pipe gaskets?

Have you vacuum synced the carbs lately?

Air filter clean?

No air leaks?

Thanks Steve! nope just the exhaust.

No i didn't replace the gaskets, the filter is brand new and just vacuumed synced the carbs

Sorry, but I don´t think you can vacuum synch the carbs if the bike can´t maintain a steady idle.
You might have an exhaust leak somewhere. change the exhaust copper crush gaskets and re-tight everything.

Valves and other things must be set before going to the carbs.
Steve

Is it possible that when you were removing the exhaust, you may have snagged the ignition wires below the ignition cover and perhaps loosened one or more wires from their respective connectors?
Can't think of anything else that could be related to just removing the exhaust for cleaning.
I'd re-inspect every wire connection (even under the seat or not obvious areas) as a sanity check so you don't end up chasing a ghost in the machine.

The carbs had been cleaned and synced before the exhaust was removed and idled at the factory specified 1100-1200 rpm range. I have gaskets on order (back orders until July 11). I'll check the wiring in the mean time. But I'm thinking it's the exhaust gaskets as they should be a crushed fit. Thanks for all the responses, I'll keep you updated as I progress.

So Finally received the crush gaskets for the exhaust and installed with some cooper gasket seal and still idles rough. My next move will be looking at the carb boots (holders) as they are pretty knackered and thinking i may have removed the carbs one too many times.

Any one have any experience with these after market carb boots:

CARBURETOR INTAKE BOOT - (FITS: '78 & '79 KZ400)

By markitzero: Any one have any experience with these after market carb boots:

CARBURETOR INTAKE BOOT - (FITS: '78 & '79 KZ400)

The description says OE. original equipment.

Yes you are correct, I was under the impression Kawasaki didn't make this product anymore.