83 xj750 troubleshooting

Hello everyone,

Straight to the issue at hand, my xj750 only runs with the choke open. It idles at 5000rpms, when the choke is halfway no real change in rpms, when I close the choke it dies.... When it runs it seems to run hot, like fuel ratio is too low. It even pops frequently.

I've cleaned the pilot jets and everything, I've checked for vacuum leaks, the idle screw is all the way down, butterfly valves resting, I've set the mixture screws 2.5 turns, I've checked for clogs in the fuel line and petcock. I even did a brief float set. What else is there?

 

this you
Good evening everyone. I've a problem I need help solving: My xj750 only starts and runs with choke on. When choke is on it idles at 5000rpm. When I turn the choke down it dies. No in between on rpms. I've cleaned all pilot jets, I've checked for vacuum leaks, I've checked the fuel lines/petcock for clogs. The idle screw is all the way down so the butterfly valves are shut, I've even set the mixture screws 2.5 turns. I've tried starting it with the gas cap open in case it's not venting properly. All the same result.... What else could it be?

turn your idle screw back in butterflies should not be shut.
you need to do a bench sync.
look into the top of the carb throat from the engine side turn the idle knob into the throttle plate until you expose half of the little hole in the top of the carb.
then set your other carbs to that point on the hole.
this is best way to bench sync carbs.

if you did a sync then closed the butterflies get bike running on choke then turn the idle knob in until the rpms start to increase , then back off the choke some.

 

Check and recheck for air leaks. Make sure carbs are properly seated in carb intake manifolds. Make sure carb intake manifold vacuum ports are sealed well. The covers on the vacuum ports rot and allow for leaks.

 

Thank you both

 

Xj550h you must have gotten that one from the Facebook group huh? Lol I thought I saw your profile picture on the members list.

 

yes I go over there from time to time. I find fb hard to follow with all the extra things that get posted at least here a thread is clear to me.