1979 Carb Rebuild (Pt 1)

tackelhappy wrote: Anyone one know why this spring is located here and what its function is ?

This is when I go to Partzilla.com and call up the parts diagram. Priceless.


What you're not seeing is 39184-1002 bracket throttle pulley. Maybe that will help make sense.
www.partzilla.com/catalog/kawasaki/motor...0-a4/carburetor-assy

I didn"t do a very good explanation earlier so will try again.
Thanks Kawboy for responding.
The photo's are from a functioning set of carbs. But they don't work good enough. One problem is the inconsistent idle . So the carbs are off the bike and setting the cable adjustment properly has a difficulty.
To describe this I will use the manual terminology and part # from page 51 of the manual.

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I cant get the bracket and stop to mate as is in the manual



I can only get it this close.











On the back of the cable bracket , as in the above photo are two rivets, one acts as a pivot, the other allows some back and forth motion that allows the bracket to move back and forth a small amount and so with some effort , forcing against the spring( 37), I get the bracket and stop to come together as in the photo--but it wont stay in that position while having to push against the spring.
So my question was, why is the spring there in the first place, and movement in the bracket

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and something that I cant seem to get right to begin getting the cables working properly.
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I think this is a great question as its bugged me for years I ended up adjusting the cables by feel in the end because like yourself I could never figure out how to get that gap to close the way its described in the service manual. Hopefully Scotch may have some input as the carb guru on this site.

Sorry to disappoint but can't add much other then to suggest the spring allows a small amount of additional relative movement between the two cables, depending on how they're adjusted.
I removed my secondary cable long ago and have had no issues or concerns.

I'll throw this out there to stimulate thought. That spring only comes in to effect when turning the throttle in the deaccelerate direction and I believe it's a damper spring to prevent placing too much tension on the return throttle cable. To set the throttle return cable, start with free play in both throttle cables and then tighten the return cable until you can pull that gap closed when rotating the throttle in deaccelerate direction. That sets the throttle return cable. Then adjust the throttle accelerate cable to get your 2-3 mm free play.
My personal opinion is that it's a bit of overkill. I can't see any situation where it would be needed. When the throttle plates close the throttle arm comes up against the idle adjust screw so that spring has no effect on throttle closed position.

Thank-you both for replying. I think back to all the Triumphs I've owned with no throttle return cable and don't ever recall ever hearing about the throttle jamming/staying open . But I can understand why the second cable was added for perceived safety reasons-you never know--it might happen.
This investigation on the throttle cable set-up was prompted by inconsistent idle- so with the tank off and watching the return action of the cables I could see very small variables in where the whole mechanism would stop after opening and closing the throttle many times- there would be a very small amount of extra movement in the link rods #-65- they didn't seem to return to the same place/stop every time - small things but significant nonetheless.
So I'll try what you suggest Kawboy and tighten the decelerate cable to pull the gap closed and go from there.