I got the bike a few years ago and did a pretty thorough resto job and it was running great. Started to use it less and less and it was getting hard to start and then just wouldn’t start. So I took the carbs off and stripped them down and sonicated them. New jets, gaskets, vacuum hoses, rubber boots both intake and air filter. Put it back together.
compression on all cylinders is over 130. New plugs, fresh fuel new air filter. New battery. Plug gaps are good.
starts up pretty poorly and the idle is terrible. Can’t get it to sit at 1000 rpm without manually holding the throttle. Got a color tone and checked the mix. Cylinder 1 is not igniting but has spark and fuel and air, 2,3 and 4 seem fine and have a good blue color with the color tone. Cylinder 1 did leak fuel out the exhaust header on startup so maybe the spark on 1 is intermittent?
Carbs are synched properly.
occasionally it will backfire even. Valve clearances are good. Primary and secondary coil resistances are in spec.
sometimes it will suddenly rev up to 5000 and stay there (maybe cylinder 1 ingited suddenly)? So then I’ll let go of the throttle and maybe a min or 2 later the revs drop and it will stall out.

think all this can be a bad igniter?

im out of ideas and would hate to have to give in and take it to a shop.

any help anyone can offer?

 

[QUOTE=itsbiga;553132]I got the bike a few years ago and did a pretty thorough resto job and it was running great. Started to use it less and less and it was getting hard to start and then just wouldn’t start. So I took the carbs off and stripped them down and sonicated them. New jets, gaskets, vacuum hoses, rubber boots both intake and air filter. Put it back together.
compression on all cylinders is over 130. New plugs, fresh fuel new air filter. New battery. Plug gaps are good.
starts up pretty poorly and the idle is terrible. Can’t get it to sit at 1000 rpm without manually holding the throttle. Got a color tone and checked the mix. Cylinder 1 is not igniting but has spark and fuel and air, 2,3 and 4 seem fine and have a good blue color with the color tone. Cylinder 1 did leak fuel out the exhaust header on startup so maybe the spark on 1 is intermittent?
Carbs are synched properly.
occasionally it will backfire even. Valve clearances are good. Primary and secondary coil resistances are in spec.
sometimes it will suddenly rev up to 5000 and stay there (maybe cylinder 1 ingited suddenly)? So then I’ll let go of the throttle and maybe a min or 2 later the revs drop and it will stall out.

think all this can be a bad igniter?

im out of ideas and would hate to have to give in and take it to a shop.

any help anyone can offer?

I have the same issue with my 1978 KZ 200.
runs OK off of the idle circuit through the top end , but the idle is too rich and it will not hold idle at stop. When I try playing with the idle slide screw I just get random very fast idle and then when I unscrew the slide screw to bring the idle back down it just dies I can't keep it idling and the plug is black and sooty.