slide diaphragm rubbers and richer diaphragm rubbers

1982 kawasaki KZ 1300-A4
I have just stripped my carby's because at the time of testing No1 carby was not getting fuel, or not much. On pulling on the choke leaver there was an initial splash of yellow then blue for about a second only. Using the colortune all the other cylinders were adjusted to a nice even blue colour but No 1 was just showing an ignition spark. Changed out the plug twice, changed HT leads with a cross over on the top coil (1 and 6 plugs to eliminate the coil being a problem) with no change, hence the pull down. The slide diaphragm on all three carb are a bit stiff and one had been previously patched!.

On the No 1 carb, the richer diaphragm was very stiff and maybe not functioning well so may as well replace the lot.

Regarding the initial problem, I have not completed the cleaning process of the carbs although they are completely stripped down now ready to be finished.

Can anyone advise where the best source to acquire replacement diaphragms might be please.

Thanks Bill

There is a listing on ebay for new slide diaphrams from France listed as membrane of bushel these appear to be a reproduction.

I dont think your issue is the diaphram at all.

It sounds very much like your Primary Circuit Lines have a blockage.
If it WAS the diaphram it would affect BOTH cylinder 1 and 2 as they share a diaphram.
As its just one cylinder..............its most likely the primary circuit lines as I have seen many times before.

You need to have your 3 x bodies all fully cleaned or immersed in Thinners for a few days to loosen up all the crap in the lines, then rebuild it and try again.
Dont waste cash on diaphrams.

Pete F
UK

Pete is correct. Based on your info you have a blocked idle passage on that cly. Search forum for '79 carb rebuild.. The internal cleaning methods are outdated, but the principles are the same. Consider the "Cleaning Tool". It's the most effective method of dealing with blockages, it's much quicker then any other method AND - it avoids soaking in potentially harmful solvents.

Scotch has designed and manufactures a Cleaning Tool which effectively flushes the Primary Circuits out making them clear again.
Other than using this tool or soaking them in thinners, you will struggle to ever get the cylinder in question to run correctly.

If you do go down the "soak" route it is important they EVERY part is removed from the carb body first, as it will damage rubber or plastic if left in it for too long.

The difference having clean Primary Circuits makes to any bike including our 1300 is to say the least ,........MASSIVE and well worth doing.

Having owned over 10 x Z1300's over the past 40 years, I have seen this issue on at least half of them and there is no way to rectify it other than the ways mentioned.
I have also seen it on many other owners bikes too.............so a very common problem.

Pete F
UK

I commenced looking for the problem and thought I should start with a full strip down and check the obvious first, which was what I could see! They are the first slide diaphragms I have ever seen hence my comments.

The carbs look pretty good with no obvious build up of "stuff" but as noted, many of the jets and primary lines are invisible.

Anyway, thanks very much for the combined information which is a great help and I think Scotch your suggestion re your tool makes the most sense for getting the clearance right the first time. I will PM you tonight.

Thanks too, Greg Davis for the location of some slide diaphragms.

Regards
Bill