1983 V45 Cyl 3 not firing

Hi Guys, Looking for some Diag help on an getting a Cylinder running correctly. My exhaust pipe is cooler than the others, much cooler. Carbs have been rebuilt by Mike Nixon, Appear to get fuel on new spark plug. Plug pulled & setting on head with engine running(5 sec) gets great looking spark. Actually fires right up with choke/fuel enrichment engaged. Also seems to get compression with plug out & running. I don't have compression gauge right now, Probably have to get one. What else can I check now- Or any known issues with 1983 V45 Cyl 3 , such as valves??
Thanks !
BadWrench

 

Had same problem try switching the plugs around
even though the plugs are new doesn't mean it is good.:cheersaf:

 

its entirely possible to be a defective plug, plugged pilot jet, blown headgasket, or any number of other possibles.

 

The fact that the cylinder picks up with the choke on indicates that there is a carb problem. It could be as simple as a synch problem, try adjusting the throttle screw for the offending carb and see if the cylinder picks up. If that doesn't work, you might need to get into the carb and check the slow jet. Might want to check the fuel screw and see if the O-ring is in place.

 

Thanks for the replies Guys!
I have been verifying the electronics since my initial post. Battery is new drawing at least 12.6Volts more with BatteryMinder charging.
Per my Clymers(I know it not great info;-) , I put a digital ohmmeter and read 492ohm & 502ohm at the pickup coil 4 pin connector which is within range to verify that the puulse generator if okay. Next the Coil Primary(input) Lugs measuered 3.2ohm & 3.1ohm which is just above the 2.8ohm spec., But another spec allows 2.8-3.2ohm so should be okay. Also, The test of the 2 secondary coil leads between 1&3 read 24.2Kohms which is fine; 2&4 read 25.2Kohms cuz they are longer. Electronics check out good including Blue Spark.
As suggested, I changed out the plug, Still not firing, But I changed after warmed up w/choke and rode, So I did notice that it didn't seem to have wet fuel which makes me think it was getting fuel only when Choked/Enriched. So, Creaky, Next chance I get, Looking into Carb issues, Thanks for the thoughts, I might also try opening the float drain to what seeps out.
The V45 runs great on 3 - Any problems for me to run around town with 3 for awhile amd hope Sea Foam clears a jet.