Obsolete Spring

Hi, All. So, I'm rebuilding the carbs from a 1980 KZ440B1. They basically came to me in a box along with the rest of the bike. I found that it was missing a couple of parts, which I have managed to replace (bless eBay). But there is one that is apparently not to be found. It is the "linkage mechanism spring." The part is pictured in the attachments. It is labeled 40 in the line drawing and A in the picture. It appears to me that what it is supposed to do is space the two carbs correctly during assembly. No other function seems obvious. Anyway, it is an "obsolete" part and no vendor who has it in their catalog can actually supply it.

Any ideas here? Beg KZ riders to look in their parts bin? Measure the space as best I can and go hunt a hardware store part? Skip it and hope that the carbs line up correctly? I'll feel better about whatever I do with advice from the list.

Thanks.

Honestly I don't know what that spring does. I am curious for other replies. I was cleaning my carbs and one of those springs fell off. It's just squished in there with hardly any effort.

Might find an answer through one of these links:

www.armbell.com/forum/index.php?c=6&sid=...571a51a&mforum=kz400

www.kz400.com/

Good Fortune!

I wrote to an eBay vendor who has been selling Keihin carb parts to inquire about this mystery spring. He didn't have one on hand, but here is his response:

"...the spring you are looking for is very common to almost all keihin carburetors try cb750 and kz750 or 750 spectre you actually dont even really need it.and you should have no problem finding one in Germany.you may even be able to find something close to it at a hardware store,its not very strong and only puts a little pressure on the two shafts if any at all."

So, I still don't know what this thing's function is, but it appears that it may not be a particularly critical one.

Of course, I'm now driven to replace the damn thing, whether or not it matters.

www.mcmaster.com/#compression-and-die-springs/=f6dcc2

Kidkawie wrote: www.mcmaster.com/#compression-and-die-springs/=f6dcc2

I would never have guessed (although I should have) that there was that much variation in simple springs. So, that kind of precludes running down to the local Ace and picking up whatever seems close.

It looks like knowing the compressed length and diameter is enough to come up with something that would be better than the hardware store route.

Thanks.

cfaherty wrote: Honestly I don't know what that spring does. I am curious for other replies. I was cleaning my carbs and one of those springs fell off. It's just squished in there with hardly any effort.

Thanks to Kidkawie (and that pretty much awesome Web site), I now know how to replace this thing. If I measure the diameter and compressed length it gets narrowed down to two available choices, and I'd just pick the weakest of the two (or so it seems). What I need to know is this: Did the spring that fell off your carbs mount inside or outside of the little nubs on the right side linkage? From the shop manual picture, it appears to be outside, but it's kind of hard to tell. Do you remember?

No prob. That warehouse is about 45 minutes from me so whatever I order gets to me the following day at noon. It's like a mega junk drawer but organized. lol

Kidkawie wrote: No prob. That warehouse is about 45 minutes from me so whatever I order gets to me the following day at noon. It's like a mega junk drawer but organized. lol

Well, I would never have known that such a place existed. I've bookmarked it, because you just never know when you might need a cool spring.

I'll go get a picture.

mwriders wrote: Did the spring that fell off your carbs mount inside or outside of the little nubs on the right side linkage? From the shop manual picture, it appears to be outside, but it's kind of hard to tell. Do you remember?

I'm not sure exactly what you mean by little nubs. The spring is captive by the slightly protruding ends of the shaft, which the spring fits over.

I.D. is 9mm. The other dimensions you can see from my attached picture.

cfaherty wrote:

mwriders wrote: Did the spring that fell off your carbs mount inside or outside of the little nubs on the right side linkage? From the shop manual picture, it appears to be outside, but it's kind of hard to tell. Do you remember?

I'm not sure exactly what you mean by little nubs. The spring is captive by the slightly protruding ends of the shaft, which the spring fits over.

I.D. is 9mm. The other dimensions you can see from my attached picture.

Yeh, those things. Thanks. That is exactly what I needed to go shopping with.