#4 cyl rich wtf????

Here we go again another rich cylinder story. Hey guys i need some help on this problem. I have a 77 kz 1000 that is a fresh rebuild. I had joe hooper do all the machine work and he did a great job. I had the cyl bored to a 1075. He did a complete head job guides and all. I reused the stock camshafts. The motor runs great, but #4 cylinder is running too rich. I have had this problem since the rebuild. I did verify with a colortune, and sure enough at mid throttle holding the throttle steady i do have orange in the sight glass. Don't think its in the carbs, due to changing jets several times while i had pods on her. I have ran it with pods and now have the stock airbox on with a new filter. I have verifyed compression, valve clearance, and had two sets of rebuilt carbs on her, with the same results. I thought it might be the choke plunger hanging up, but don't think so since both carbs are doing the same thing on the same cyl. I set the floats with clear tube. I have a new dyna s with green coils. I checked voltage at coils,and swapped plug wires over from cyl 1 to 4 with no luck. I have new carb holders. Any help would be greatly appreciated, i'm pulling my hair out.

oppie501 wrote:

Here we go again another rich cylinder story. Hey guys i need some help on this problem. I have a 77 kz 1000 that is a fresh rebuild. I had joe hooper do all the machine work and he did a great job. I had the cyl bored to a 1075. He did a complete head job guides and all. I reused the stock camshafts. The motor runs great, but #4 cylinder is running too rich. I have had this problem since the rebuild. I did verify with a colortune, and sure enough at mid throttle holding the throttle steady i do have orange in the sight glass. Don't think its in the carbs, due to changing jets several times while i had pods on her. I have ran it with pods and now have the stock airbox on with a new filter. I have verifyed compression, valve clearance, and had two sets of rebuilt carbs on her, with the same results. I thought it might be the choke plunger hanging up, but don't think so since both carbs are doing the same thing on the same cyl. I set the floats with clear tube. I have a new dyna s with green coils. I checked voltage at coils,and swapped plug wires over from cyl 1 to 4 with no luck. I have new carb holders. Any help would be greatly appreciated, i'm pulling my hair out.

Looks like you covered the bases well.

When you swapped the wires on 1&4, did you swap the plug caps as well?

I think you're saying it did the same thing with pods as with the airbox...but if it didn't...Inside the airbox are screens. The one on the right isn't by some chance blocked up over #4 intake boot?

Or possibly did something get stuck inside #4 header primary while the engine was apart?

Did a leak down test on cyl #4. Found small amount of leakage out the intake valve:( . Anybody know if a valve with a little leakage will seat in. I had a reputable company do a three angle valve job with new guides and valve seals. I have about 650 miles on her. If there is a chance it will seat in, I don't want to tear it down.