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Discussion Starter · #1 ·
The throttle cable (single cable) on my '82 Kawasaki KZ750H sticks when the engine is cold, and particularly when the choke is on. I have to kill the engine if I rev it up before it is warm, as jiggling the throttle won't drop it back. After it's warm enough to cut the choke, it seems better, but I don't trust it. The cable looks fine and is not kinked along it's length. I can't see why the choke setting effects this, but it does.

What is the easiest way to lube the cable? And where is the return spring (it might be weak)? Thanks!
 

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Navy Vet Search & Rescue
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I'd venture to guess your throttle isn't sticking. It's normal for the idle to go up with the choke on. With the choke on it's getting more fuel and the more the engine warms up the higher the idle becomes until the engine is so warm that the extra gas starts to flood it out. You should gradually take the choke off as the engine warms up to maintain your idle around 2k. For my bike it usually takes 2 adjustments before finally turning the choke all the way off, when going from cold to warm.

But just in case your throttle cable is sticking, the springs are located on the throttle linkage between each pair of carbs. And the easiest way to lube the cable is with one of these.

Cable Luber Tool - - - - - - - - from Z1 Enterprises, Inc.
 

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Discussion Starter · #3 ·
Yes, I understand what the choke does, but this is different. This bike won't start when cold without using the choke. Once it's started, but still cold and with the choke on, if I tweak the throttle for just an instant, say up to 4 or 5000rpm, it stays at that rpm, and no joggling of the throttle will bring it back. I have to kill the engine to stop it.

Once warm, and with the choke off, it's okay for the most part (although, while rare, it sometimes still does this).
 

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Navy Vet Search & Rescue
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You may be suffering from an air leak/crack in the carb holders. If it's a relatively new crack it will be small. When the rubber is cold it contracts allowing the crack to suck in extra air, as it warms up the rubber expands and can swell enough to close the crack off mostly. Next time you start the bike, take some carb cleaner and spray all around (top, bottom, both sides) the carb holders (the rubber that attaches the carb to the engine). If you hear the engine rpm surge when doing this, you found the crack. Don't make the mistake of thinking it's not cracked just because you can't see the crack with your eyes.
 
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