Fluttering Tach at Idle

Ok, so I jsut completed my first carb sync. Glorious. She even SOUNDS better. I dont detect any kind of Popping at all now. Which is sweet. I'm about to go and Re-check my plugs to see what they look like after a slight adjustment, a ride, and idling for 3 min in the shed.
#4 was a real black and looked kind of oily...
So after my sync, my Tach now "flutters" a little bit. She's warm up and sit at 1300, and flutter gently up to 1500. You can hear it in the engine too. She continues this pattern, 13, then rise to 15, then drop back.. Hmmmm..
Any ideas?
And my #4 Header pipe is not as hot as the rest. Its pretty warm! But not warm enough to leave exhaust hickeys on my fingers..
I think it may be a piston seal is broken or soemthing.. which isnt good, but There is a solution
-SLKid

 

Scratch the No-Popping comment.. I cant STILL hear it between 25 and 3500 RPMS. And its popping when I decelerate.
~sigh~ Ya'll were right. This fine tuning process is lengthy, and somewhat frustrating

 

Well, i adjusted the Idle screw down a bit to its normal 1000-1050 range and it cured the flutter a liiill. It sounds better. Still got that pop and Oily plug on 4.. soooo, I'm going to pull the carbs and adjust the floats by 1-1.5mm and pull my main jets to see whats up in there.
Maybe the float on 3 or 4 is a little low and causing the pop?? We'll see.
Inputs welcome!!
-StreetLegalKid

 

Is it really oil on the plug, or black soot looking stuff?
If it is black soot, you are too rich.

Which would also explain the warm but not hot header.

If it's oil, you got other probs!

 

If you have an oily plug then there is oil getting in the combustion chamber. It's probably either the piston rings or the valve seal. A compression test will help you determine which.

 

Thanks guys! Been dying to hear some input.
I <i> THINK</i> its oil. I know what carbon rich looks like, a dull matte black. This is shiny. My digital camera sucks so a pic would do no justice.
I can definatly do a compression test.
Would you explain to me how my results dry and wet on the compression test will help determine? I'm curious to know and love learning
-SLKid

 

First do a compression test on all four cylinders. I think the reading should be around 140-150 psi. More importantly all cylinders should be close to each other. Haynes manual states the max difference between cyclinders is 14 psi. If cylinder 4 is reading low then add a small amount of motor oil (about 1 teaspoon should do) into the cylinder through the spark plug hole and do another test on that cylinder. If the reading improves then its the rings letting oil through. If it doesn't get better then it's the valve stem seal. If its the valve stem seal and your comression is too low on that cylinder then you probably have a ring issue as well. BTW if you have to replace the rings its always a good idea to replace them as a set. Same goes for valve stem seals (which you should probably replace anyway if they haven't been already) Hope this is helpful and good luck.

 

Yeah thats amazing!! I keep all this info stored away and use it allll the time. I LOVE having useful info. I really sppreciate it
-SLK