Mixture Screws Different Lengths?

The other day I was adjusting the mixture screws on my '77 KZ650 to try to help it run better for these last few weeks of the season (it needs a proper jetting because of the pods the previous owner installed = my winter project).

Well the screws were tough to loosen while on the bike, so I took the carbs off in order to break them loose.

I tightened the screws all the way, without forcing them, and noticed that they all stuck out into the carb at different heights.

You can see what I'm talking about here:
imgur.com/a/mUQZI#0

Is this normal? Did some of the tips break??

Thanks!!
-Stephen

Not sure if it's normal or not, but should not be a big problem as long as you set the screws using the lean-drop method. Once they are set right, you can count the number of turns it takes to close each one and see if the number is the same for all screws. If so then all is good.

If the number of turns is drastically different, then you will want to check the condition of the screws, assuming all other carb settings are right. It's a long process and mixture and synch are at the end of the process. Start by confirming engine compression and valve lash. Then ignition timing. Then make sure there are no exhaust leaks around the head. Then check carb fuel levels and confirm there are no fuel leaks. Then check for vacuum leaks.

The last three things are to test the jetting and synch and mixture, but these all go together, and you usually have to go through each several times as any one will affect the other two, So you go thruogh iterations until you close in on the final settings.

Being careful to remember which carb each pilot screw came out of, could remove them all and compare them among themselves, including any springs, o'rings, and washers attendant to each screw, and paying special attention to condition of the pointed tips.

Presupposing that each pilot screw is the correct part for the carbs at hand, each pilot screw began its life looking exactly like the other pilot screws with the same part number.





www.z1enterprises.com/ItemDetails.aspx?i...carb&item=SIK-1157SK

Good Fortune!

loudhvx wrote: Not sure if it's normal or not, but should not be a big problem as long as you set the screws using the lean-drop method. Once they are set right, you can count the number of turns it takes to close each one and see if the number is the same for all screws. If so then all is good.

If the number of turns is drastically different, then you will want to check the condition of the screws, assuming all other carb settings are right. It's a long process and mixture and synch are at the end of the process. Start by confirming engine compression and valve lash. Then ignition timing. Then make sure there are no exhaust leaks around the head. Then check carb fuel levels and confirm there are no fuel leaks. Then check for vacuum leaks.

The last three things are to test the jetting and synch and mixture, but these all go together, and you usually have to go through each several times as any one will affect the other two, So you go thruogh iterations until you close in on the final settings.

Thanks for the great info!

I've got good compression, but have yet to check my valve clearances (have new gasket already but need shims).

Just got new coils, but replacing my whole points plate very soon (PO stripped all the points screws so I can't adjust anything >_<)

I think I'll just go for a whole carb rebuild this winter-- buy a rebuild kit plus a few different jet sizes and see how it goes. I'm currently building a homemade carb syncing tool to use once I've done all that!