Idle issue

I've got an 81 kawasaki 440 ltd that I was riding before winter, the bike was running well but had a small issue with what sounded like popping air leaks, probably from 30 year old carb boots. I replaced those this spring and got it started but now when I turn the choke off the idle goes way higher than on choke, so high that after a few seconds I turn the bike off because I'm afraid I'll blow the engine. Would I be wrong to suspect an air leak at the air filter? (it's old and pretty cracked) But if so why is the choke acting opposite of what it should be?

-I apologize if this issue has already been posted but I searched here and other internet sites and haven't found a similar post.

Thanks

Waldorf wrote: . . . 81 kawasaki 440 ltd . . . was running well but had a small issue with what sounded like popping air leaks, probably from 30 year old carb boots. I replaced those this spring and got it started but now when I turn the choke off the idle goes way higher than on choke, so high that after a few seconds I turn the bike off because I'm afraid I'll blow the engine. Would I be wrong to suspect an air leak at the air filter? (it's old and pretty cracked) But if so why is the choke acting opposite of what it should be? . . . .

Does carb "boots" refer to carb holders?
Or does carb "boots" refer to airbox hoses?

Possible loose clamp at carb holder, or incomplete insertion of carbs into holders?

Good Fortune!

Yes refers to the carb holders, and they are definitely tight and I'm pretty sure everything is seated correctly, but I will definitely check again.

As known, a "racing idle" often results from an air leak.

Properly installed new carb holders are likely not the air leak source.

Possibly a cracked or ill-fitted vacuum cap/plug?

Is clean air system paraphernalia fitted?

I don't suspect an air leak at the air filter.

Good Fortune!

Is the closed throttle position actually fully returning the carb to its idle position?
Possibly more slack needed in the throttle cable?
Is throttle cable frayed inside?
Does throttle cable need lubing?

Good Fortune!

I'll check the vacuum plug. What do you mean by clean air system paraphernalia fitted? If you're asking about the air box I haven't removed it or changed that at all.

Would be similar to the following clean air system on a KZ750 twin.


Many of the stock clean air systems on various Kawasaki models have already been permanently removed.

If the bike at hand came stock with a clean air system -- I don't know whether it did or not without looking it up -- it may have already been removed.

Where the stock clean air system remains fitted, its several hoses and connections are a fertile source for air leaks.

Good Fortune!