1977 KZ-1000A1 Needle Jets

Just happen to have a REAL Kawasaki parts book for the Kz1000A1 and the Kz1000A2.

This should give you the correct part number for the Kz1000A1 needle.

According to the kit shown by Scirocco the needle jet you need is a series 258, size O-6. The jet needle is a 5CN8, set in the middle clip position. (3) That said, you probably don't need to change the jets right away. You might want to try to run with what you've got and save your money for now. Also of note is the price from the site Scirocco posted. It's about the same price un US$ as the kits sold by Z1 Enterprises, which have a lot more parts in them.

Rick H, If you want i can offer you a new set (4x) of #243 O-6 needle jets and jet needle #5DL31.
They are left-over parts out of an Keyster KK-0161NR kit, (76 KZ900 A4).

www.motorradbay.de/kz900a4__br_year_76-k...a70e956c727eb78a9401

PM sent Scirocco…

Rick H.

All left-over parts of the Keyster KK-0161NR kit.
Rick, do you want all parts or only the jet needles and needle jets?

I don't know if the diffuser will fit behind those needle jets. The jets have an extra extension on the bottom end.

Good point hardrockminer!!! My needle jets are looking different (longer) so i am out off the game.

Normally I'm the first person here to tell newbies to bust down their carbs and clean them properly. If we had a dollar for each person that "cleaned" their carbs only to have to do it again (and again...) the KZR server time would be all paid up for years to come. Anyway, this thread is the first time I've ever seen where guys were promoting replacing parts that I wouldn't. Most times a set of carbs like these VM's will last for 100k miles if they are taken care of without doing anything other than maybe updating the soft parts at some point.

Nessism wrote: Normally I'm the first person here to tell newbies to bust down their carbs and clean them properly. If we had a dollar for each person that "cleaned" their carbs only to have to do it again (and again...) the KZR server time would be all paid up for years to come. Anyway, this thread is the first time I've ever seen where guys were promoting replacing parts that I wouldn't. Most times a set of carbs like these VM's will last for 100k miles if they are taken care of without doing anything other than maybe updating the soft parts at some point.

I must say I'm always amazed at how many folks replace Mikuni VM carb metal parts. I've ridden my KZ650 more than 62,000 miles and the only parts I've ever replaced on the Mikuni VM carbs are the float bowl gaskets. I find it difficult to understand how the metal parts wear out, especially on bikes that don't have very high mileage. I guess I can understand if folks install pods or some other non-stock air filters and are searching for the magic combination that will make the engine run well, but often it seems folks believe there is a reason to replace metal parts even when using the stock air filter. Ed

I agree with Nessism and Ed....if I know the bike's history and it's been well cared for. If not, which is the usual case then pretty much everything is suspect.

Here is what Kawasaki said in their Motorcycle Systems Training Manual for carburetors (Overhaul section) about needles and needle jets. Bear in mind that the needle is held loosely in place. When the engine is running, particularly at higher speeds air rushes past it, pushing it towards the edge of the needle jet. The needle is sliding up and down and will rub on the needle jet.

"Check the jet needle for signs of rubbing. If the needle has been rubbing, it would be against the needle jet, and this too would have to be replaced. A worn jet or needle will allow too much fuel to enter the engine, resulting in a rich mixture. The main jet and pilot jet rarely "wear out" but should be checked for clogging, deformation, or stripped threads."

I've always found it interesting that rebuilders will change the main and pilot jet despite those not being wear items, but will leave the needle jet, which IS a wear item. In my experience new needle jets (and needles) will result in a smoother operating engine and improved fuel economy. On one of my Z1's I saw mileage go from about 45 miles/imp gallon to 60. So I am a fan of changing out needle jets (and needles) in vintage bikes where the bike's history is unknown. The true test would be to measure the inner diameter of the jets and change if they have gone oval, but I don't have the equipment to do that and the cost of a set of carb kits is minimal. So I do it every time I rebuild a set of carbs.

Perhaps I take to heart too much of what I read, but seeing as though my KZ-1000 has what I figure at least close to 20K miles on it I thought it would be in my best interest to replace the "needles". I did not see the needles in the used parts bags I was given from the place that overhauled the carbs and it seems pretty apparent needles were not in the K&L overhaul kits that they supposedly used. I just thought with the carbs off the bike now would be a good time to make sure they are up to snuff. I must admit sometimes it can get somewhat confusing when a lot of information is given to one of my novice questions, so I just take a conservative approach and best guess it after reading everyone's responses. I like knowing things because more knowledge is better than too little. I can honestly say without the help and knowledge of a great many people on this website I probably would have just sold the KZ after I got it and no doubt taken a big loss. Yes I have spent way more on this project then I ever expected, but if it all goes back together the way I hope it does it should be a terrific motorcycle. Hopefully I will get the new needles before I put the carbs back on the bike, but if not that's okay too because Old Man Winter is knocking on the door and it will give me something to do. Thanks to all!!
Rick H.

20k miles? The bike is still a baby. Ed