Choke and startup problems-Carbs

Well Folks, it seems my '83, 750 SECA runs a little rich. I'm new to this bike, got it last Sept. It has an OEM exhaust, and air box on it now. I had it running last fall OK, but after the weather got cold, this problem emerged.
Start up: If I use any choke, the plugs get soaked with gas, only #1 cylinder will run.
After warm up, I clean the plugs and run the engine again, #1, 2 and 4 plugs working, but #3 gets sooty within 3 minutes. At sustained mid throttle RPM, plugs stay clean.
The things I have yet to do are:
Check valve clearances.
Close the idle mixture screws down below 2 turns out.
Sync the carbs.
Road testing before April will be rare.
Any suggestions?

 

Check to make sure all for floats are the correct height. Also make sure all the jets are in the right place and that your emulsion tubes are clean.

Those were my problems when I had one cylinder running too rich.

If your choke is flooding out your cylinders then you theoretically should be able to start without it. Seems like it's warm enough to not shrink the gas to the point were you need it.

Dial all the mixture screws to 2.5 turns. That's where a lot of bikes like to be for first testing, especially when it's cold.

 

Sounds like its time for a good carb synch and color tune, along with making sure the carb float valves are all working properly. But before you do any of that, check the valve shim clearances and make sure they're correct.

 

baz,

Are the carb float valves the same as making sure the float height is correct? I've always heard both but never sure if they're the same thing or not.

 

I believe when Baz says "carb float valves" he is refering to the needle valve that should seat to shut off gas when the bowl is full.

 

I ordered a Colortune tool, to aid the idle mixture adjustments. Will any Redliners submit some opinions?

 

Did it used to have pods and you put a stock airbox on it?
If so do you know the size of the idle jet?

 

It has the OEM airbox, but one PO put Harley mufflers on it, the OEM exhaust system on it now replaced those. I never started or ran it with the Harley mufflers.
I don't know the size of the jets, for sure I don't want to take the carbs off again. (But how are they measured?)

 

The jets are stamped with a number.
My 650 has 040 idle and 110 main jets.

I am wondering if your idle jet was upped by a PO.
Turning the idle screw tighter may solve it. Def try that first.