Valves

I have a 1978 LTD 1000 stock engine. Finally got the bike running really good, however there is an issue with the number one cylinder. The plug is not terrible but it is black where the other three are like chocolate milk. Idles a tad rough but runs great from there on out. When I took the valve cover off to adjust the valves I noticed the exhaust cam lobe on number one was discolored. Valves are all in speck now but I think I may have a bad valve?   . You guys have been a great resource in getting this bike back on the road after 10 years so hopefully someone can shed some light on this. If indeed I have a problem with the valve, is this something I can remedy without a machine shop? Thanks again.

The cap and bearing journal also look discoloured (possibly heat) is that first cam bearing tight ? (wouldn't effect how it runs though) is the black plug wet (possible oil or fuel from a leaking choke plunger)

If the bike runs well, you are likely okay.  Maybe check compression (warm engine, throttle held open).  Also, sync the carbs, and put a fan in front of the engine when you do so.  Lots of times people overheat their engine by idling too long without air flow.  These engines are tough, but things like that cam lobe can occur.  

Intake is .076 and exhaust is .063. Getting my service manual out to see what a cap and bearing journal is, lol. 

The fuel screws are 2 turns out on 2, 3 and four. 1 1/4 on 1 and the plug still looks like this. 

Typically, the fuel screws should be set at somewhere between 1/2 to 1-1/8 of a turn open.  People running pod air filters often go off the chart, though.  

Carb synch is the next thing I'll do. Shouldn't all the air screws be pretty close to the same? 

Sullivan wrote:

Carb synch is the next thing I'll do. Shouldn't all the air screws be pretty close to the same? 

In your last post you said fuel screws, and now you mention air screws.  Which is it?  Air screws are open farther than fuel screws.  More like 1.25 -  2 turns open.  And yes, they should be within a reasonable range of each other, say 1/2 turn.

My apologies. They are the stock VM26, thus
they are fuel screws. 

Mine are not close. This, I assume I have a problem. 

If the screws are on the side of the carbs they are air screws.  If they are on the bottom on the outlet side they are fuel.

If you still have the valve cover off...check your valve clearance and adjust any that are too tight.  Shoot for 0.15 to 0.20 clearance.  If the valve cover is back on...take it off and check clearance.  Then...

Do a compression test...pull the plugs, start with gauge on #1 cylinder and open the throttle wide open.  Hold the starter button until the gauge stops increasing.  Do the same with all 4 cylinders.  

If all of the above is OK, then next step is to check your carb float levels.  While you're at it check which pilot jets you have installed.  Hopefully they are all the same.  

This "heat-colored" cam lobe is a typical sign of too much heat on the outlet valve:

Valve clearance to too tight or NO clearance ?
Missing Oil / lubrication on that outer corner?
Overheating by lean mixture? ( but sparkplug looks too black /wet for this example..)
Timing too late ?