Hello Doug yes thats pretty much what mine does. Not a backfire just a strong poof. does'nt run bad just very anoying and trust me gona figure this out if it kills me. As for the voltage I did'nt feel it was that low but been wrong before. After I get carb back together gona try disconnecting any accessories and lights see if that lets voltage come up at idle then see what happens. Thanks for all your helps Gentlemen, Stay tuned!

 

I could be wrong, but, Harley use to retard the timing on the rear cyl. a bit from the front, because it runs a little hotter being out of the slipstream of cooling air. Not sure if they still do that on the EVO or not, but it would account for your hillbilly plug check being weaker on the rear cyl.. One other check you might try is to slow the idle down to where it drops the VOES off from lack of vacuum, and see how it idles there. It will be so slow that you can tell when both cyl. are firing, and they should both sound pretty strong with the timing retarded. I know mine does anyway. I have a toggle switch on my VOES so that I can cut it off manually if I want. Works well to check to make sure it is working, and if I want to listen to a really slow potato potato. I know, I know, a lot of guys say that they get no oil, but I know guys that have been idling there EVO's for years below 600 without problems. True, there is not much oil pressure, but there is plenty of volume, and the oil guys I have talked to about this say there is plenty of lubrication as the engine has basically no load on it at idle. Just my humble opinion, as none of us knows for sure.

 

First off the engine should have more than 4 inches of vacuum at an idle. Check that ouit first!!! Try another gauge and go from there.

 

If yours is wired at the circuit breakers like mine was the ignition and lights breakers are connected meaning if you put the ignition to ignition you would get some tour pack lights on and if you put key to lights you may get more lights depending if anyones rewired. I snipped the green jumper wire from lights to ignition breaker and now get no lights at all while in key ignition selection ( bike running ). I found after installing new cycle electric 38 amp that there was a definate drop in volts with lights on at idle.
As for the rear cylinder firing more retarded then front, this is why so many of us change ignition to programable so we can advance the rear a bit. Then again we don't it there on a lawn chair all day just so we can listen for the potato potato.

 

Miacycles i have around 9 inches of vaccumn the 4 inches is what it fluctuats. When at idle the needle jumps back and fourth from 6 to 10 inches which I figure would be normal at low rpm. It smooths out with rpm.

 

"A strong poof?" sounds like those guys on that website my wife looks at late at night :-)

 

I have an update. I went through the carb and did find the washer that goes bettween the oring and the spring on the mixture screw was missing which damaged the oring. Yes maybe this is it put in new oring and washer put back together (dang) same thing!! Got to messing around with the airfilter off and noticed at idle it's pulling fuel up through the emulsion tube not sure whats up there checked and double checked the float height removed carb again to recheck and right on the money, Thinking maybe something amiss with the dynojet emulsion tube I reinstalled the factory tube and 190 jet, Same thing. Played around with the mixture screw and when backed out to 4 turns it stop flowing through the tube. This makes me believe it's ruuning way rich and need bigger pilot. I have a 48 pilot on the way so we will see what happens then. It's my understanding that if you have to go more than 3 turns out you need a bigger pilot correct? I guess if the pilots to small and mixture in to far it creates more vacumn over the emulsion tube.

 

BUT! Why would it run good before and all of a sudden start doing this

 

Its a Harley, they do strange things from time to time. Maybe wear inside the motor on one pot or valve means it has different mixture requirements now?

 

Just want to give a follow up for anybody interested. I received my pilot jets today and installed the 46 jet and much better so tried the 48 and man what a differance, has much smoother and stronger idle. Not sure why this occured when ran well before but don't really care as it runs great now, I think better then it ever has. Mixture screw is 2.5 turns out and no more slobering. Thanks to all who have participated with this thread. Todd