TOPIC:

The screws that hold the diaphragm assembly together are secured with thread-lock !   The ones I just received were fully coated !   Most of these screw-heads were already stripped.  I used a worn-down (to  1/2")  Dremel  slitter disc to "slot" the heads.  I used a lacquer-thinner soaked Q-tip to soak both ends of each screw.  A lot of pressure was required to keep the slotted screwdriver in the slot, and I found it necessary to work the screw in/out as I slowing backed them out.  In this way was able to remove all of them with no surprises or mishaps.  By some fluke, I found I had a M3X.35P tap !  This was used to remove the thread-lock from internal threads.
The four screws that secure the diaphragm assembly together are M3X.35P.  If you have a need to remove these be warned:  The Philips heads are soft and will strip easily - even with a JIS driver and I've concluded after hours of searching that M3X.35 is a "bastard" size so good luck finding replacements ! 
Re-tapping for a more common size/pitch is a viable option and should be within the capabilities of most. 
 
Side note: I cannibalize various things for their unique parts and  fasteners. I discovered I had several M3X.35 screws of the correct length - just not 12.  So they are out there - in lots of products - just not readily available to purchase.  I guess I'll have to wait for a couple of more "Keurigs" to bite the dust !

I found something unusual about the holders I purchased.  With the slides on, the assembly wouldn't drop-in.  They got stuck within the first 1/4" of insertion.  Loosening the four screws corrected this.  Once the assembly was in and fully dropped I tightened the screws and all was OK.  So there can be an "alignment" concern if the assembly has been taken apart and reassembled.   These ones were misaligned because a P.O. had removed the diaphragms and then put them back together. There's just enough play between the parts tor this to occur.
That's one solution for the issue.   
I discovered another -  equally effective.  I used a small Dremel rotary-stone to smooth-out the edges of the notches in the holder. Not much more than a quick touch to remove the slight roughness from the stamping process. Again - end of problem.   
This doesn't affect the needle height, in case that was your next question !  It simply provides a few Thou. of additional movement to provide a drop-in ability.   
A "fix" for the stripped screw-heads until they can be replaced, worked quite well.  I cleaned the heads, and filled them with solder.  I drilled a 1/8" hole in a piece of steel (Backing for the head) , inserted the screw and using a Philips-head "bit" "struck" a new pattern into them. The displaced solder was easily removed and this was more than adequate allow them to be tightened. 
Keep in mind:  The screws are flush for a reason !
Hope this is of some interest/help.  No one likes to get Screwed-Over" 

 

dcarver220b wrote:

www.z1300.de  ?

Nachfertigung vom nicht mehr lieferbaren Vergasermembran mit der Ersatzteilnummer 43028-1014
Passend für alle Vergasermodelle 
  
Translated
Reproduction of the no longer available carburetor membrane with the spare part number 43028-1014
Suitable for all carburettor models

His stuff is much better, across the board, than eBay sh@#$t IMHO of course :)



 

Right off the top, the MCG diaphragms look very different than the other 2 options from Legend Motorcycles and Djin1378 EBay sellers. Now the question is how thick are the MCG diaphragms?? Anybody?? Don't make me buy one for testing purposes !!

 
Legend Motorcycles KZ1300 diaphragm

 

MCG (KZ1300.de)  kz1300 diaphragm.

Another thought that came across my mind- If the throttle pistons are not reacting the same then there could be a battle between the butterfly plates and the throttle pistons not co-operating and there could be some areas of the rpm range where the 2 are fighting each other. The Mikuni RS series of carbs that they used on the Kawasaki triple 2 strokes only have cable actuated throttle pistons and no butterflies or diaphragms.

The more I get into this the more I'm convinced  that I will be going to fuel injection using the Microsquirt ECU for Ignition and Fuel Injection Control but in the meantime I am a carb guy and trying to help as best as I can.

First, we are entering a time when replacement OEM parts are nearly non available and we are forced to rely on good people trying to build good parts to help us keep these beasts alive. Who are these people and do they know what they are doing?? Who knows. It's almost as bad as 30 years ago when a lot of "aftermarket" products were coming out of China. Quality was dismal to say the least although in the past few years things have gotten better and sometimes worse. It's a crap shoot. So buyer beware and thank God for sites like this where we can share information and experiences.

The diaphragms from Legend Motorcycles in the United Kingdom
Cost- As of this writing Legend sells these individually at $17.91 USD each and comparing that price to the offerings at www.z1300.de priced at 29.90 Euros each ($32..29 USD) , or the other EBay offering from DJIN 1378  who offers a set of 3 for $74.99 USD ($24.99 each comparison price only). 
Bottom line Price wise, pretty good.

Material- Neither Legend or DJIN1378 would outright tell me what material their product was made from and both told me that they sold hundreds of these diaphragms and no reported problems. I have not contacted Z1300.de for any information and all I wish to do here is comment on the Legend Motorcycles product.
I also want to bring to your attention that the Legend Motorcycles diaphragm does not have any reinforcing material in the diaphragm like the Kawasaki OEM diaphragm. Now the elastomer has to perform the work of controlling the throttle plunger as opposed to the Kawasaki OEM diaphragm which relies on the reinforcement to do the work of controlling the plunger and the rubber portion of the membrane to seal the reinforcement 
 Bottom line- I have concerns about the ethanol compatability and I have a concern about the lack of reinforcement.

Fitment-  At first glance I really like the way the diaphragm sits in position in the relaxed position. BUT when I went to install the top cap, I noticed that I had metal to metal contact between the cap and the carb body. Hmmmm, No pinch on the diaphragm?? Measured the depth of the outer groove in the carb body and then measured the thickness of the diaphragm that fits in the groove and the groove measured .082" and the diaphragm is only .072" thick at the same point, This means when all installed, the diaphragm is not sealed to the top cap and there will be air leakage from atmosphere outside the carb, through the seam between the diaphragm and the cap reducing the vacuum applied to the cavity and this will likely cause the plungers to not rise as they should.
This could be overcome by trimming down the carb body by .015" to create a pinch on the diaphragm and properly seal the chamber under the cap but in my mind this is a big problem that was overlooked when they manufactured the diaphragm. I measured up the thickness of the OEM Kawasaki diaphragm at .085" and at the very least, Legend should have had the replacements made to the same standard as the originals, so no Brownie points here. I have a concern about the OEM diaphragm since at .085" thick installed in a .082" deep groove, there is only .003" of pinch. Considering that O-rings require a 10% compression to achieve a seal and the diaphragm is .085" thick where it sits in the groove, the OEM diaphragm should have been .090" thick to meet the standard and it's not, so even the OEM diaphragm is questionable in my mind. Standards are standards for a reason.
Another issue I confirmed- There were reports of these aftermarket diaphragms having the locating tab out of place and this is another problem. when installed the locating tab on the outer diameter is off by about 5 degrees and it's impossible to install the diaphragm/plunger assembly and the only way to make this diaphragm work is to cut off the locating tab and assemble as carefully as possible so as to not invoke a twist in the diaphragm which might bind the plungers. Another faux pas.

 
This pic shows how far off the locating tab is to the locating spot in the carb body.



this shows a straight edge across the carb body to indicate the recess on the inner diameter that allows the diaphragm to relax inside the groove. So no pinch of the diaphragm inside the lip on the outer diameter. In a nutshell, the diaphragm is located and pinched in the groove only as if the groove was filled with an o-ring. 

Bottom Line- it's a viable product. Cost wise not bad, Material undecided and only time will tell. Fitment, If you're willing to shave down your carb bodies to create a pinch on the diaphragm, I see no reason why these won't perform. But if you're not capable of trimming down the carb bodies, I would suggest these diaphragms are not for you.

Hopefully you'll find this information useful

The carb-set I purchased recently had no diaphragms,  The only OEM's available are used ones found on eBay and they are rare !. Currently the only ones for sale on eBay are noted as "for parts only" because the actual diaphragms are torn. 
Kawboy's review (Thank You) raised the same concerns for me. It shouldn't come as any surprise that I decided to make my own.  A challenge to say the least.  I made four sets (12), each set an improvement on the previous.  Finally figured out some of the tricks needed to make them and have a set installed in the carb-set I just finished rebuilding.  . 
The short story:    Two pieces of .006" nitrile with a synthetic fabric core.  Not exactly as "user friendly" as OEM's or the questionable aftermarket ones, they none-the-less are just as pliable as OEM's and the raising and dropping of the slides is identical to OEM's. 
   Diaphragms do not come in contact with fuel so I have no concerns in that regard but some road testing will prove / disprove whether the effort proves viable.
The material cost for a set (3)  is about $12.00cdn.  The time involved to get to this point......Priceless !