Not F6B but Honda bike related

[stevenolts]

Maybe someone can help me with this problem.
It is winter and I have cabin fever already so I finally got back to working on my 81 Honda CB750K
I know it is dumb to take apart a good running bike. I just have to play with my old friend to make it better for my older age upright ridding position.

Everyone makes their CB750K into a Cafe Racer / I am making mine a Sports Touring bike.

Quick Background:

I wanted to raise the handlebars:
pulled carbs to measure and the change throttle and clutch cables
since I had it apart I pulled the carbs apart to clean and fix the leaky overflow tubes
installed new cables
installed carbs

bike fired right up (yeha!!!)

cut cables to extend
extended cables / solder and shrink tube
bike starts but doesn't run good

took carbs back off to replace the boots and free up sticky choke cable
replaced the carb boots
fixed choke cable
installed carbs with good seal on all boots both sides (first time in many years)
drained gas / fresh gas
no leaky overflow tubes

bike won't start

I was checking the spark (seems very weak and intermitten)
but the bike started and ran on 3 spark plugs
I put the spark plug back in and the bike started right up

It is 16 degrees so I was letting it warm up and slowly releasing the choke
bike had good throttle response for being cold
bike died

I can't restart it again
I thought maybe it is flooded
took spark plugs out to air out
I replaced spark plugs with new iridium plugs I had ready to replace
still won't start

How do I set the initial settings on the carb after disassembly / I set all screws inside carbs to manual spec
(maybe I need to adjust something main idle screw under carbs ???)

The best thing is even in the cold weather my new best friend starts right up even with more than twice the miles as the 36 year old Honda. (I love fuel injection)

Help!!!!!
Steve

[speeddrive1]

Not sure about the spark issue but the only way to that I know to set the carbs is with the vacuum operated carb synchronizing sticks. You could also check valve clearance as valves that are to tight can cause hard or no starting.

[Steve 0080]

Coils were notorious for going out on them back in the day.... A stator now and then also???

[glryder98]

Sounds like a fuel problem to me. First I would check the fuel shut off and see if fuel is getting to the carbs.
Next I would check the fuel bowls to see if they have fuel. Unscrew the screw at the bottom of the bowls and see if fuel comes out. Next thing to check is spark at all plugs not just at 1. 1 coil fires no.1 & no.3 cylinder and the second coil fires no.2 & no.4 cylinder. Make sure battery is fully charged. If battery voltage drops below 10 volts while cranking bike won't start.

[BobR]

Here is my 1974 750K with a few modifications done back in 1975. I went through the carbs and completely rebuilt them. Only use Honda parts as many of the aftermarket parts are not right and will cause drivability issues. The Honda parts are not cheap but she fires up @ the touch of the starter button. Also, get rid of the dual points and get a dyna electronic ignition and you will not have any more problems.Attachment 25127