Rear cyclinder is running rich,blows black smoke,This is an 80 in. new build,ported heads,three angle valve grind,EV 27 cam,I've tried every jet combo in 2 S&S ''E'' carbs,one brand new,Tried Dyna S ignition,Dyna 2000i single fire ignition,Tried one turn through 4 turn combination adjustments to pushrod adjustments,leak down tests on valves show no leakage,compression is even@95, no leaks in manifold,What the Ef!?

White smoke blown head gasket or cracked head ,antifreeze in combustion chamber . blue is oil bad rings or valve guides . Black smoke is fuel. Running to rich.

If it's running rich already, a bigger jet will just make it run even richer.

As far as the rear cylinder running hotter, that's just the nature of the beast with a V-Twin engine, because the front cylinder blocks the airflow to the rear.

It could be jetted too rich,the choke could be engaging at WOT,or,you could most likely have weak valve springs which are "floating" the valves at higher RPM's.Also,you might try lowering the needles in the carbs by a couple clicks.
Good Luck!

What color is the smoke? If the smoke is white, it's oil smoke. If it's fuel, it'll be black smoke.

Generally, black smoke from the exhast indicates a too rich mixture for one reason or the other. You said you rejetted the carb. This could be part of the problem. You also said that it's only out of the front pipe. If you rejet the carb, it effects both cylinders. If you have a vacuum leak on the rear cylinder, this could cause the front cylinder to run rich.

If the smoke coming from the front cylinder is white smoke, you may have a oil problem. It could be rings, a valve stem seal, or a head gasket leak. But, unless the smoke is heavy and the bike runs good, I wouldn't worry about it. If it bothers you, have a leakdown test run on the engine. That should tell you where the problem is. Or, just do a top end overhaul on the engine and be done with it. Have a new set of rings installed or have it bored and new pistons if needed. Also have a valve job done on the heads. This should solve the problem as you'll have to replace the intake gaskets when you take the intake and heads off.

Don't just keep throwing money at the problem. That gets expensive and is only successful part of the time. Anytime you have a problem with one cylinder only, whatever is wrong is confined to that cylinder. Anything that you do that effects both cylinders is usually useless. I would suspect a valve stem seal on your bike. You didn't say how many miles you have on the engine nor what type of carb you're running.

Good Luck
Steve

black smoke is fuel white smoke is oil. change your spark plugs to a hotter plug and run with some hpr 50 engine oil or somrthing nice and thick

most deffinately an internal issue. 2 possible problems oil seeping through valves when engine not running. sitting in combustion chamber and burns off during start up. 2 piston rings in one or more cylinders bad and letting oil blow by and start up is only time it is really noticeable.

If it's the org. engine it will has over 150,000 miles on it.
It's normal to has the valve stem seal/oil seal on the head to leak oil into the cyclinder.
The smoke you see is the motor oil drop from the seals.
It land on the top of the cyclinders and it create black smoke at start up.

The inexpensive fix is to start using high mileage oil with seal conditioner.
This will help soften the rubber seals and help reduce internal oil leak.

The correct fix is to wait until it's time for a head gasket replacement and let the professional service the head.

Complete head service is the only method to stop this internal oil drip problem.