Lost my signal light, engine runs like crap

I never thought this would have developed into such an issue with the engine, but here goes my story. Today, I went out for a ride, and the streets being what they are, I lost my left rear signal light and stem , and wire with bullet connection pulled out. The stem broke off the taillight mount off. I didn't realize that this had happened, but at my next stop I parked, and the engine was running crappy. I got out my little screwdriver and started adjusting the carb throttle stop settings.
Then after being at my appointment for 1/2 hour, I still didn't notice the signal light missing, but I had a hard time starting the bike. Made a few more stops, got some fuel, then went back home on the freeway. At every stop the idle was erratic, sometimes surging. When I got home, is when I noticed the missing light. I also noticed that the left exhaust header was really blue, almost black, at the first bend...and this is the header that stays very clean, always the chrome color. It is my right side header that is always bluish. So I retraced my route, and found the light, but only the stem, and wire are fine. The lens and lens mount were smashed. I don't know if this is something that happens when part of the electrical system is at fault, or missing, but right after I lost the left signal light, the engine idle was terrible, and look what 1/2 hour of riding did to my left side header pipe. I know that 90% of carb issues are electrical, but this was a real eye-opener. I will get a replaceement signal light and mount, and I will try to get the taillight mount welded for the signal light stem, or just replace the whole unit. I won't run the bike til I get the signal replaced.

I know of absolutely no reason the loss of a rear turn signal would cause a rough cylinder -- especially one running very hot/lean as you describe.

Drop the float bowl on that left side and unscrew the main/needle jet holder...


(See #22/#23)

... to check that the needle hasn't dropped out of its retaining clip to where it no longer rises with the slide, and instead just sits there blocking any gas uptake through the main.

I'll do that tomorrow....if I find the needle has slipped off its clip, what slot in the needle should the clip be on?

presumably in the same clip as your other carb

Middle position/groove is the default.
(Oh don't we hope for a simple fix....)

p.s., You have Reserve on the left? Take the time also to:

- Check that gas flows from each petcock and hasn't been blocked by something in the tank/caught in either petcock intake.
- Check the float free movement/height
- Check/blow out the jets
- Check/ensure you have gas actually free-flowing into the bowl/through its banjo filter
- Check that gently depressing the float after fill/shut-off causes the bowl to refill further to overflowing

Bottom line in all of this is whether you have normal gas actually getting from the tank, through whole system, and into the carb mixing chamber/cylinder. Your symptoms would say you don't.

I agree with the other guys that you're running very lean on that one side. The only coincidence I can think of regarding the loss of a signal light is if you happened to hit a pot hole or bump in the road that broke the blinker off and also shook the carb. Check carb mounting bolts along with what the others have said.

My reserve is on the right, and I will check for fuel flow on both sides. I don't recall hitting a large bump, or pot hole, but the coincidence does make sense. Forgot to mention that the Boyer stator plate wires are failing. I have got the replacement wire fix on order but will be a couple of weeks til they arrive. I have placed some foam rubber around the wires which isolates them nicely from vibration, in the meantime. I'd like to get this resolved before my wife and I go on our vacation tomorrow, but I may not get the time to check things out until my return in 10 days.
Any other ideas or suggestions are welcome and appreciated.

Just a thought but are you sure that the broken wire wasn't causing an intermittent short circuit ? If the ignition pick up connections are failing then you will have rough running.

Did you just adjust the throttle stops or the idle mixture as well ?

The wire insulation is fine, it is the usual vibration issue that the Boyer wires are prone to.
I got a chance to do some checking....both spark plugs look normal, I switched from NGK's to Champion N3C's last week. When I pulled the left hand plug I was expecting very lean indications, but it looks a slight tan color on the insulator, just like the right hand plug. Fuel flows freely out of tank on both sides. Fuel flows correctly to both carbs. I only had a chance to remove the float bowl from the left hand carb. Banjo bolt filter is clean, everthing in float bowl is clean, float works fine, with no fuel in float, and float needle also fine. The jets were clean, I removed, and blew out anyway. I will have to check right hand carb when I get back home. So far, the only thing I have changed recently, has been the spark plugs, and using that foam rubber to isolate the Boyer stator plate wires. When I get back, I will check out the right carb, then fix thos Boyer wires, and put the NGK spark plugs back in.
One question, I was talking with a mechanic and he said blue pipes are from a too rich mixture, unspent fuel is burning in the pipes, yet I hear from others that this is a too lean condition...which is it?

I've always heard (and experienced) bluing from overly-lean conditions. But I went back and searched the web for further discussion.

4-ot-of-5 cites attributed bluing to lean burn. One, however, said both rich and lean along the lines you described:

In case your pipes become blue too quickly or over and over again,
it can be a manifestation that the air-fuel mixture or timing is not
right or accurate. To overdo the mixture and make it overly rich
can turn the pipe or muffler blue. This is because the unburned
gas ignites on a baffle or hot spot. Too lean mixture or timing
can cause pinging. It can also turn an extremely hot exhaust into
blue. (cite#1)

~~~~~~~~~~~~~~~~~~~~~
Gold and blue pipes result because the exhaust is running too hot.
There are three reasons for this. The first, most common reason,
is that the bike is running lean. A lean mixture causes exhaust
temperature to rise very sharply. A slightly rich mix WILL NOT
CAUSE BLUED OR YELLOWED PIPES.

However, a *VERY* rich mix can result in an extreme case of bluing.
This happens when the mix is not completely burned in the
combustion chamber, (either due to a too rich mix, malfunctioning
coil, burned valve, improper timing, or whatnot) and rather ignites
INSIDE THE EXHAUST. This can result in an exhaust pipe that
GLOWS RED while the bike is running. Only in this extreme case
can a too-rich mixture cause bluing. (cite#2)

Since you've checked that no (gross) fuel-flow problems are evident,

1. Switch back to the old plugs (and/or) switch the current plugs left/right and recheck
2. Switch coils left/right. (Failing coil shoving unfired gas mix into pipe, only to be ignited by the next cycle that does fire)
3. If #1/2 above doesn't show a difference, can/have you run a timing check on the offending cylinder? (Although the Boyer fires(?) both cylinders simultaneously.)

I,m away from the bike now, but thought I'd review the forum. I forgot to mention that while I had the carb float bowl off, and had pull the jets, the needle seem secure on the slider, and when I turned the throttle, the needle pulls up fine. I don't yet know what the needle clip setting is though. Thanks for the last response regarding pipe bluing. I will do a coil switch, and see if the condition moves to the other pipe.