carb/ fuel delivery problem

[scott68]

1984 johnson 70 hp. from the start of the season the motor has been giving me a hard time starting, some days are worse than others but once running it is fine. this wknd it wouldnt start at all after sitting out in the river and had to get towed in. i'v changed the fuel line with no change at all, tanks are vented properly and all tanks have the issue so it's not the tanks. since i've owned it (4years) it has always given a problem on holeshot, it will stall unless i push the choke in before it has a chance to stall and then goes. end of last season i rebuilt all the carbs and no change with this problem. if i spray pre mix in the top carb when it is getting ready to stall it takes off, the rest bog when sprayed, so obviously there is a problem w/ the top carb. any help would be great as i am getting aggrivated

 

[mikesea]

Re: carb/ fuel delivery problem

when you did the carbs did you soak them so all the gunk in the tiny passages cleaned out,as you note you have an issue with 1 for sure,I would pull them again,get a carb solution at a local auto store,soak the carb bodies an bowls after all rubber was removed,a couple hrs,you should then take a can of carb spray and shoot through every port,jet hole etc,you should remove thejets if you can allows for a better job,after soaking in solutionI like to soak in hot soapy water,then hit with the garden hose ,then the carb spray,be sure your filters and hoses are free of crud ,fuel pump 2

 

[jtexas]

Re: carb/ fuel delivery problem

Assuming you did a good thorough job with your rebuild..........I had this problem once when I was lake testing a carb rebuild - bogging on acceleration - without even loading the boat I took out the hi-speed plug screws, stuck the straw of an aerosol carb cleaner in there and gave 'em a few short blasts - cleared it out - apparently somewhere between the garage and the front yard, something (dog hair, dryer lint, mosquito, whatever) found its way in there. Not a substitute for a good carb cleaning, but........

course that doesn't explain your hard start....is it hard to start warm, cold, always? what's your compression?