Topic: Help, 750 is coughing and then dying.

[bjatwood]

Could be electical related. Ground short of points plate issue?

[Vinhead1957]

So do all the plugs have a good bluish purple spark?  A spare plug can be used to verify this

[Bootlegger56]

Are the overflow tubes plugged or clogged?  Are the brass overflow tubes inside the bowls plugged or clogged? 

[jollyradar]

No points plate. CycleX power arc ignition, may call Ken tomorrow and talk about the possibility of that failing.

I have spark, but it is difficult to tell if it is missing, or just rpms slowing.

I'll check the overflow tubes.

[scottly]

Video of how the bike is operating.
Not a valid vimeo URL

That is indeed weird!?
Check the fuel level in the float bowls with the "clear tube method". My guess is two carbs have low fuel levels, and two have high fuel levels?

[bjatwood]

After watching that video, I think the fuel line routing just might be the issue....definitely sounds like the bike is running out of fuel.

[jollyradar]

It can't be a fuel issue before the bowls. The bike will run fine for a couple of minutes with the fuel shut off. I keep missing Ken at CycleX, I'll try again tomorrow.

[bjatwood]

It can't be a fuel issue before the bowls.

Ok good luck

[K3Owner]

You should let it die again on its side and then check the plugs. It will at least give an indication of where to look: wet - ignition fault likely. Sounds like chafed wiring is an option as well. Drain the bowls after that to be sure there is still plenty of fuel in each. As I read, there is still lots of guess work going on.

Heck, you can run a carb dry by letting it continue to drain if you want and take that cylinder out of the equation. Don't flame me - makes sense if a carb is dumping fuel that it runs dry and she won't choke when leaned if that's the bad cylinder. She's choking like crazy so sounds like 2 are dying and that's definitely ignition related. Always ignition first.

These things are tons of fun to troubleshoot. At least yours is misbehaving while sitting in the garage. Mine is missing at speed so I'll have a fun weekend playing with the carbs as the entire ignition has already been replaced...