TOPIC:

I found these pictures of the 2 needles so i could compare them.
The first image with the single jet needles is the ones i need (N01A).
The second image is the ones i have on mine, the N10A.
Ive noticed that there is quite a big difference in the shape of the needles in that the N10A's are quite straight, whereas the stock kz750 LTD needles are quite tapered in.
Now im thinking that if i get a set of these stock N01A needles for what could be dollars as they seem a bit like hens teeth, are they even going to fit the needle seat?
It would seem unlikely due to the big difference in shape and It seems like that needle seat is pressed in and unchangeable? unless someone knows of a way to change that seat i think this is going to be a bit of a futile attempt and im beginning to think that maybe i should just give up on thses carbs and try to get another set that are the 'proper' ones, god knows where and how much this is going to cost me though?!

Edit: After looking at the parts fische and my manual i cant seem to figure out what part & # the Needle seat is, it looks like the 'seat' i'm talking about could be the 'needle jet' that the 'jet needle' seats into? am i right on this and if so perhaps it can be changed after all?
Cheers

Your edit is correct.

Jet needle = long pointy thing
Needle jet = small cylindrical thingy with a hole through it. May be threaded into the carb body, depending on the particular model. If so, replacements may be available.

As I think mentioned, the slide cutouts can be different depending on which brand the carbs were originally built for. It would be a good idea to insure that all four have the correct cutout. There's no telling what might have been done over the last four decades.

TexasKZ wrote: Your edit is correct.

Jet needle = long pointy thing
Needle jet = small cylindrical thingy with a hole through it. May be threaded into the carb body, depending on the particular model. If so, replacements may be available.

As I think mentioned, the slide cutouts can be different depending on which brand the carbs were originally built for. It would be a good idea to insure that all four have the correct cutout. There's no telling what might have been done over the last four decades.

When you say slide cutouts do you mean the holes at the bottom of the inside of the slides? I'll do a bit of online hunting to make sure they are correct, thanks.

Throttle slides among various carb designs have different cutaway sections on the air intake side of the slide.





Good Fortune!

No eBay APP ID and/or Cert ID defined in Kunena configurationGod knows where and how much?

SK - the needle jet is the "little" brass bit that jet needle passes through and needle jet holder is the big brass bit that screws into bottom and base of jet needle sits.
You shouldnt need to replace these .
I have bought a couple of sets CV 32's - about $170 each - bit of fiddling and they work fine.

No eBay APP ID and/or Cert ID defined in Kunena configurationSo not had a great deal of luck with these carbs since last post. I've rang up a few carb specialists i managed to find in the UK but they couldnt offer that much help and wern't to sure if i changed the jet needles over etc if it would actually get the bike running properly, They recommended me to get another set which i think perhaps is good advice, So ive been hunting around for some replacements and seems most of the ones listed are on the US eBay site. ive found these ones:

but they have a stuck slide, they are from an '81 model though, I dont suppose anyone would happen to know if the H or E carb models 81-83 might be interchangable? Im thinking that as long as they have the N01A jet needles and the same secondary and main jet sizes then it shouldnt be a problem in theory should it? Haynes manual seems to say all the H and E models have the same sort of set up. I cant find H4 specific model Carbs anywhere so think im going to have to compromise a bit.

Considering these:

=http://www.ebay.co.uk/itm/161429492685#viTabs_0

It's risky to purchase used CV carbs because of not knowing condition of the diaphragms.

Good Fortune!

Yea true, however i do have a pretty decent set of cv34's with good diaphrgams/slides though so im thinking i could swap some bits over if needed, I'm not sure what else i can do really, think im running out of options with this one :/

Special KK;

The first set of carbs above seems to have all the bits including the polyester pilot caps and they note it has a stuck slide
The second set doesn't even appear to have jets and is probably an even bigger crap shoot. And neither offering mentions diaphragms as per Patton

from parts diagrams (search KZ750 in the Filebase here) you can see that carb parts for the E1 and H1 appear to be totally interchangeable so I would think the H4 would be the same. You could look for a set of Mikuni BS34s from an 82 or is it 83 Gpz750 ?

I wonder if you changed to jet needles to to N01A type would they work without changing needle holders etc ?

I keep thinking that it must be something simple that is causing the problem and that those Spectre carbs should still work. These old air cooled motors are usually pretty forgiving.

Looking back at the link I posted a few pages back where Wiredgeorge said ........
The other type of CV34 was used on later models using this carb and the mid-range was far richer. It used a N100 (N10A ???) jet needle. The mid-range was richened by use of a #68 primary main jet. The main jet was relatively small #92. The best way to rejet this carb for pods/pipes is to leave the jet needle alone and leave the primary main alone and use a #130 main jet.
Last, as memory serves, there is only one hole in the bottom of the slide to relieve pressure. We have never noted much difference drilling these holes in the bottom of the slide as far as throttle response goes but it likely doesn't do much harm. Use a 1/8" drill bit.......... would it be worth a shot going back to the 90 or 100 secondary main jets which were in the carbs when you got them ? I'm just thinking you cleaned the pilots and replaced the secondary main jets with 130s at the same time. Have you tried a plug chop at 6k ? - find a quiet road, run the bike up to 6k, kill the motor and look at the spark plug colour

You say the bike wont rev above 6k RPM in neutral or while riding in gear. Does it stutter or just not go any faster?

Could it be as simple as a short throttle cable not fully opening the throttle flaps/butterflies ?

Other things to check - valves, voltage at coils. I think you checked battery V.

Sorry that we have been unsuccessful in helping to date
Good luck

Ah yes well spotted on that eBay listing, i did notice it had the plugs missing but not the jets! Also i noticed that it says that buyer may not get carbs that are pictured so definitely a potential crap shoot like you said, i dont fancy getting stuck with an expensive useless set or having to send them back to America from here and paying postage costs twice!

Its funny you say about changing the jets up to 132's when i cleaned out the pilots, because i actually thought about that a while ago but it totally skipped my mind that i did it at the same time until you just mentioned it. Im going to give that a go first thing tomorrow and get those 90's back in and see if they will work on the off chance.

I took the diaphragms out the other day and pulled the throttle lever whilst watching the butterflies open and close inside the carbs and they all seem to open to a flat horizontal position so think the throttle cable and setting is good.

It doesnt stutter in neutral just doesnt rev any faster.

Been looking for Mikuni BS34's for past week cant seem to find any about anywhere though, will keep looking.
Will check valves and need to check timing too, think i checked coils already although doesnt seem like electrical problem because i checked the sparks with an inline spark tester and seemed to be firing pretty solidly and consistently, but i will double check these.
If all else fails i may give the other jet needles a go after all, i can get some replacement N01A's from NRP carb specialists up North who were recommended to me by Z-power, I was wondering what do you think would happen if i changed them and the needles were seated loosely in the needle jet seats due to slightly thinner taper? would it be a case of fuel getting sucked up past them at idle and putting the whole system out of sync perhaps or do you think it wouldnt make much difference? it doesnt seem to be a very tightly sealed part of the carbs when you think that the needle jet just sits inside the jet needle without an o-ring or whatever.

If all that fails then i guess thats when i should be looking at a fresh set of carbs.

No worries on not solving it yet, its just one of those tricky ones, im sure it will get sorted soon (i hope!) all been very helpful so far and muchly appreciated!