One cylinder running rich

Nate, Please amplify your comments, they make no sense to me. What is a "main jet needle"... are you talking about the float needle? As it fits up in the seat, it protrudes out of the seat perhaps .25mm? Not much, but they add a spring loaded pin for contacting the float. Unless an incorrect needle were used, how could it be a different height? Not trying to be a wise-guy... would just like to clear this up. Perhaps you are thinking in an entirely different direction I am not seeing. God bless and thanks! wg

N0NB wrote:

There is always the chance that the main jet needle is a different height than the others.

Patton wrote:

N0NB wrote:

There is always the chance that the main jet needle is a different height than the others.

kzrider.com/media/kunena/attachments/leg...mages/jet_needle.jpg [/img]

Here's a better pic of jet needle (I hope)

Patton wrote:

N0NB wrote:

There is always the chance that the main jet needle is a different height than the others.

The Keystar rebuild kit I got for my BS38s had needles which were about 1/8" shorter than stock.

Patton wrote:

Patton wrote:

N0NB wrote:

There is always the chance that the main jet needle is a different height than the others.

kzrider.com/media/kunena/attachments/leg...mages/jet_needle.jpg [/img]

Here's a better pic of jet needle (I hope)

And here's a typical float needle, sometimes referred to as a float jet needle

I took it to mean that the carb has it's main jet (not float needle) set richer than the rest of the carbs.

I used the clear tube method to check the fuel level in #4. It was level with the bottom of the carb body. I adjusted it so it was 1/8" below the body and the bike ran like crap. It was backfiring and terrible throttle response. It also had a wandering idle. One minute it would idle too slow and almost die, then if I blipped the throttle it would idle about 1500rpm for a while, then slowed down. I pulled the carbs off and the o-rings on the idle mixture screw and the tube the main jet screws into are shot.

I ordered a rebuild kit for all four carbs. I noticed I have 107.5 mains and 15 pilots. My Clymer manual lists 107.5 mains, but 17.5 pilots for a 77KZ1000 standard. Should I put 15 or 17.5 pilots in it?

Oh, and I did check the needle in #4. It has the correct needle and the clip is in the middle position, which my manual lists as the stock setting.

If you have K&N Pod Filters, which you did not specify, and the aftermarket exhaust system which you said you have, than normally you have to jet your carbs a little richer than stock. I had these same issues with other bikes I have owned. But still does not explain why one cylinder is rich and the others are fine.

The bike has a K&N filter in the stock airbox. It has a Vance and Hines 4-into-1 pipe with baffle.

Hopefully between a good cleaning and the rebuild kit, this will fix my problem.

I just got done disassembling the rest of the carbs. Three of the four idle mixture screws have been blunted from overtightening. They are over 1/8" shorter than the one good screw. The carbs were pretty dirty too. I'm shocked the bike ran as good as it did. Now I just need my rebuild kits.