Z550 jet sizes

anyone know the jet sizes for KZ550 or GPZ550 4 cylinder bikes?

To be accurate, we'd need to know the year and letter designation. Are you asking about the 1981 KZ550 D (GPZ)?
Here's a chart for some of the early 550's.
This chart represents the models using TK21 or TK22 manual-slide carbs. Later models with CV type carbs are not represented here.
The same bikes, made in subsequent years, using the same carbs most likely have the same internal setups. For example, the 1981 KZ550C2 and 1982 KZ550C3 would have the same setup as the 1980 KZ550C1, because they also use the TK22 carbs. However, the 1983 KZ550A4 uses different carbs than the 1980 KZ550A1, so its setup would have to be different.:




As you can see, the 550 models A (standard) and C (LTD) use #92 main jets. The 550 D (gpz) uses #94. All else is basically the same in those models' carbs.

Post edited by: loudhvx, at: 2007/12/12 12:36

this was following on from my z500 aftermarket filters thread, any chance of a picture showing the 'clip position and adjustment on the Z500, TK22?
if i fit pod style filters will adjusting this position 'up' the jetting?

iandz500 wrote:

this was following on from my z500 aftermarket filters thread, any chance of a picture showing the 'clip position and adjustment on the Z500, TK22?
if i fit pod style filters will adjusting this position 'up' the jetting?

The needle only affects intermediate throttle positions. You still need to change the jetting to have correct wide-open mixture. When you put in a larger main, the intermediate positions get a little richer, so sometimes you don't have to mess with the needles.

If I can find a drawing I'll post it.

I see I'm not the only one with ???
Loud I think you answered the ? I posted on the other thread (550 high idle after assembly). It sounds like you are saying that if we go up to the D1 models #94 mains - after changing to pods - needle adjustment is unnecessary, so long as at intermidiate range is satisfactory. Is that pretty close? Are we assuming stock exhaust ( I hope.) ?
BTW- Thanks Ian for the links to carb parts site!

I see I'm not the only one with ???
Loud I think you answered the ? I posted on the other thread (550 high idle after assembly). It sounds like you are saying that if we go up to the D1 models #94 mains - after changing to pods - needle adjustment is unnecessary, so long as at intermidiate range is satisfactory. Is that pretty close? Are we assuming stock exhaust ( I hope.) ?
BTW- Thanks Ian for the links to carb parts site!

I see I'm not the only one with ???
Loud I think you answered the ? I posted on the other thread (550 high idle after assembly). It sounds like you are saying that if we go up to the D1 models #94 mains - after changing to pods - needle adjustment is unnecessary, so long as at intermidiate range is satisfactory. Is that pretty close? Are we assuming stock exhaust ( I hope.) ?
BTW- Thanks Ian for the links to carb parts site!

Aric wrote:

I see I'm not the only one with ???
Loud I think you answered the ? I posted on the other thread (550 high idle after assembly). It sounds like you are saying that if we go up to the D1 models #94 mains - after changing to pods - needle adjustment is unnecessary, so long as at intermidiate range is satisfactory. Is that pretty close? Are we assuming stock exhaust ( I hope.) ?

Yes, at least if you're lucky you won't have to mess with the needles. I am assuming stock exhaust on your bike.

On Ian's 500, he has pods and a 4-into-1 exhaust. He has the exhaust, but his bike started out with 90 jets. Hopefully both of you can get away with just main-jet changes. In case you need to adjust the needles, here's is a graphic I drew up for the 3 different types of needles available for the the TK-22 carbs.

home.comcast.net/~loudgpz/GPZneedles3types.gif

Unfortunately, jetting takes some patience.

On Ian's 500, he has pods and a 4-into-1 exhaust. He has the exhaust, but his bike started out with 90 jets. Hopefully both of you can get away with just main-jet changes. In case you need to adjust the needles, here's is a graphic I drew up for the 3 different types of needles available for the the TK-22 carbs.

home.comcast.net/~loudgpz/GPZneedles3types.gif

Unfortunately, jetting takes some patience.[/quote]

is there a way of checking the size of the jets fitted? i've read #90 and #92, will it be stamped/engraved on the jets?

According to the factory manual, it should have been 90 from the factory. We are talking about the KZ500B, correct?

yep z500B 1980 vintage

Forgot to mention...
I've come across stock jets that were labeled and some that were not.