Changing diaphragms

So I´m about to renovate both ends of my BS34 CVs, all essential parts in the float chambers and also change diaphragms.

The slide has the two plastic rings pressed together holding the diapragm, I´ve seen videos where people destroy
them with plyers, which means that the replacement diaphragm will only sit in the groove, I assume this means
that you can´t sepeate them and join together again with the new rubber?

Best--Martin

Here is a thread from a couple months ago on this same topic... www.kzrider.com/forum/forum-index/3-carb...iaphragm-replacement

There are various other threads in the archives as well if you feel like searching.

The stock diaphragm is sandwiched between two plastic retainer pieces, then a lip on the top of the slide is roll formed over the top which captures the assembly. To remove the old diaphragms you either need to remove the roll formed lip or destroy the plastic retainers.

JMB diaphragms have a decent reputation but are expensive. I've never tried them. I ordered some diaphragm's from china, as shown in the linked thread, but in the end they didn't fit properly into the groove in the carb body with my BS34's.

To fix my slides I harvested good diaphragm's from some Suzuki GS slides and transplanted them onto the KZ slide bodies using the method shown in my thread. They turned out beautifully but it was a lot of work and of course, you need a lathe.

I have two spare used OEM Kaw BS34 diaphragm sets, and wonder what they are worth.

:whistle:

daveo wrote: I have two spare used OEM Kaw BS34 diaphragm sets, and wonder what they are worth.

:whistle:

The diaphgram's alone or with slides?

Nessism wrote:

daveo wrote: I have two spare used OEM Kaw BS34 diaphragm sets, and wonder what they are worth.

:whistle:

The diaphgram's alone or with slides?

This set came from a set of KZP carbs. Each slide has a hole filled with JB Weld as shown below.
Ran in my KZ1100 BS34's for several seasons with no issue:





The second set does not have those holes.

The Chinese diaphragm's I bought were claimed to be for KZP carbs. I figured they were the same as every other BS34 but the diaphragms don't fit my set. I'm not sure if there are different types of BS34 diaphgrams or if the Chinese diaphragms are junk.

Edit: apparently there are different size BS34 diaphgrams based on JBM info. I didn't realize this before.

Nessism wrote: The Chinese diaphragm's I bought were claimed to be for KZP carbs. I figured they were the same as every other BS34 but the diaphragms don't fit my set. I'm not sure if there are different types of BS34 diaphgrams or if the Chinese diaphragms are junk.

My battery was Made In China, but that is the only such made part on my bike. It still cranks like new after six riding seasons! Bikemaster Tru-Gel

daveo wrote:

Nessism wrote: The Chinese diaphragm's I bought were claimed to be for KZP carbs. I figured they were the same as every other BS34 but the diaphragms don't fit my set. I'm not sure if there are different types of BS34 diaphgrams or if the Chinese diaphragms are junk.

My battery was Made In China, but that is the only such made part on my bike. It still cranks like new after six riding seasons! Bikemaster Tru-Gel

The Chinese diaphgrams seem like good quality parts. They are pure rubber, like Keihin diaphgrams, but unlike the OEM Mikuni diaphgrams which have a fabric core.

According to JBM there are two different sizes as shown below...

Quite a chart there, Ed

Wish I could make tails of it...

What do the measurements refer to?

:huh:

daveo wrote: Quite a chart there, Ed

Wish I could make tails of it...

What do the measurements refer to?

:huh:

Updated the chart.
It seems there are BS34 and BS34SS carbs (according to JBM.) The carbs I've been working on use the smaller diaphragms. I've studied the parts fishe under the various years 1000 and 1100 bikes and can't make heads or tails relative to what year bikes get what slides. All I know is the Chinese diaphgrams are the larger size.

Nessism wrote:

daveo wrote: Quite a chart there, Ed

Wish I could make tails of it...

What do the measurements refer to?

:huh:

Updated the chart.
It seems there are BS34 and BS34SS carbs (according to JBM.) The carbs I've been working on use the smaller diaphragms. I've studied the parts fishe under the various years 1000 and 1100 bikes and can't make heads or tails relative to what year bikes get what slides. All I know is the Chinese diaphgrams are the larger size.

What is the sale value of my pictured set?
Thanks

daveo wrote:

What is the sale value of my pictured set?
Thanks

No disrespect Dave but those diaphgram's look kind of thrashed with the distortion and waviness. I suspect they would run fine for some time but they are not in what I'd call optimum condition. And that sealed over hole is a little questionable. It's hard to assign a value. Personally, I'd put the set at $50, but there are guys asking $50 each for slides on ebay so who knows?