83'VF 750 starting problem

83' with 16K, fresh rebuild on carbs, new fuel filter,no rust in tank;first started, ran fine ,drove around the block and through all gears . Days later it would only start on full choke and stall if given any gas at all . pulled the carbs , checked the jets ,main ,slow speed all OK . No air leaks . Checked the fuel pump and got good flow . Now it will only start on full choke and run for about 2 seconds then shut down . All cylinders are firing . It seems that the only thing left is the ignition ? Any suggestions would help . The right solution gets you moved to the top of my Christmas list , this is making me nuts ! Thanks for your time , Henderson

 

How many turns on the pilot screws do you have? For electrics I'd try the ignition box connections in the tail section. They get wet and will oxidize and get spotty contact. Then ign and kill sw wiring. Hard to tell at this point.

 

Is there any electronic component that will fail gradualy ? I checked the conections ; seen just fine . The bike has never been left outside . I'm the original owner . The pilot screws are as they came from the guy who rebuilt them in Texas . It ran just fine when I first started it . Then went south in stages .
Thanks for the prompt reply......H

 

Sounds like your idle jets are clogged.

 

You said the guy in Texas rebuild your carbs. Where do you live, Texas? Was this a take them off ship them to him type deal? If so where the carbs sync'd on the bike after install? Were the pilot screws(idle circuit) adjusted on a warm/hot engine? Unknown rebuild on carbs is a big question for me.

No matter who rebuilt them, they have to be sync'd and adjusted for idle on the running bike only. Also possible dirty tank.?? Fine rust will clog the carb filter screens above the needle seat and or the fuel filter under the fuel pump. When it shuts down, put a cup under an easy to get to carb and open the drain screw. gas should come out. If not or very little, then there you are. Time to back track the fuel system.

 

What really puzzles me is that it fired up and ran fine for several miles the first time I started it . the problem ; only starting on full choke and stalling when given any gas prompted me to pull the carbs . they were free of rust , the jets were clean the pilot screws were in there proper position and there was good clean flow from the pump . I drained the tank before starting the project with no rust comming out . I also replaced the filter and even cut open the old filter and found no rust or any build up of anything .Good clean fuel comes from the carb bowls .I'll try pulling the carbs again and recheck everything , I'm getting really good at it by now . I appreciate your helpful sugestions and the time you have taken . If you guys are ever in the Washington ,DC area ; the drinks are on me.........H