1985 VF500F Carb Issues

Yes, my bike has a fuel pump, and it is functional. I am using an auxiliary plastic tank at the moment with fresh fuel in it... I have replaced the fuel filter.... fuel seems to be getting to the floats ... and it will start right up when fuel is sprayed directly in the carbs...

 

make sure the idle speed adjustment screw is set properly for easiest starting. back the screw off until you sense the butterflies are fully closed, then turn the screw one turn in.

if you're trying to start the engine it always helps to have the airbox and filter in place.

 

Pardon the dumb question, but by "idle speed adjustment screw" do you mean the single, black idle adjustment knob? Also, I have been trying to start with the airbox open .... I will do as you suggest and adjust the screw and close the box and try again before I pull the carbs again....Also, should I continue to spray fuel into the carbs when I try to start it?

 

yes and yes.

does your choke work ?

 

Also, should I continue to spray fuel directly into the carbs, o

Yes. Choke works. I assume full choke, no throttle to start…

 

He's had it running with fuel directly to the carbs AND he has opened the bowl drains after the attempted carb clean and the bowls had fuel from his remote fuel source (not the original tank).

All of this does not rule out the carbs were not assembled correctly as it ran with external fuel source but leaked before the carb "service". In any case, the carbs need another go knowing it was not done correctly.

 

No... clean the carbs correctly.

Yes... full choke, no throttle.

 

While it should start with the air box lid and filter out, they really don't like it and affects it greatly.

You already know the engine doesn't make any strange noises and runs. Time to fix what you didn't so you can rule those items out and then move on to the next culprit if needed. Looking for other issues when you didn't (properly) eliminate the one you wanted to is a waste of time.

 

I understand your point. I will pull the carbs again.

 

using full choke--if the carbs are properly adjusted and clean--may be too much and flood the plugs if you crank too long. suggest you try with 1/2 choke.

the choke won't work at all if its fuel pickup tubes are clogged, something common.





if the tubes are clear you should be able to insert a wire about 30mm in.