Carb problems; where to get new diaphragms

Hey guys. I have an 83 kz750 spectre 

A friend of a friend said he'd clean and sync the carbs for me for $100-$150.

Long story short, he seems to keep having one issue after another, the most recent being him saying the diaphragms were shot. Found a set that he said should work... He installed them and said they won't slide and we need a different set. 

It's been a couple weeks and he says he can't find any replacements. 

What are my options here?

Have you checked here?

jbmindustries.com/diaphragms.html

These might also be worth considering, a little more expensive but pre-assembled ready to install needles and fit ? (I assume these are Mikuni carbs ?)



 

It's very unusual for all four carb diaphragms to go bad at the same time.  Maybe if someone dunked the carbs, with the slides attached, in some harsh chemicals?  

JBM K-71 might work.  Your bike has Keinin CV34 carburetors.  The Spectre carbs, and slides, are different from the more common CV34's as used on the 750E/H bikes.

I've got a bunch of spare CV34 slides, but I think they are the earlier type.  Have to check.

I have used JBM diaphragms and the work well.

Checked my spares, and I have 2 full sets of the earlier slides, but none of the later type needed for these carbs.