I replaced everything on the fuel side of the motor, starts ok, idles fine, the second I move the throttle forward it dies, are the coils bad? I need some help. Good compression 130, new plugs, new fuel pump, new carb parts, still won't run.
You can get a spark tester from an auto chain for $5 or so, most OBs jump about 3/8" on them. Check your main jets and floats, it will be on the idle jet when carbs are closed. Is your timing right?
Im not an expert can only share what has happened to mine similar.
Fuel pump diaphram had a hole in it so the motor did not get enough fuel to run at speed.
Secondly when I shifted from netural to gear it used to stall unless I throttled up alot. Old timer at marina told me to put a thermostat in it, since the motor never got warm enough to stay running. Don't know if it was crap or not, but has been running fine since.
You might want to check the check valves in the fuel pump, if they go bad it would not pump fuel as it should. Fuel now days has a lot of alcohol in it that tends to ruin these check valves.
Usually stalling with applied throttle is a classic fuel supply issue.
Fuel should have strong evenly spaced pulses from an unhooked line.
Be sure the piuse port and associated parts are clear.
I put new check valves in the fuel pump, I still have the same problem, starts idles in gear, apply the gas fast or slow it dies, starts when in neutral. I have replaced everything from the tank to the fuel pump and on to the carb no results. It has spark, fuel, compression.
It appears not to be fuel related, so let's go electrical. Check for bare/rubbed wires on throttle advance. Any wire that moves when throttle is advanced
when you apply the electric choke it still dies. could the neutral safety switch cause it not to rev up ???? a friend had a merc same problem, replaced the coils it ran fine after coil replacement.
I still need some help here. Fuel side is in good working order as it is all brand new. Where do I start on the electric side ??? Great spark, still quits with any throttle advance, it is like you turned the key off, will not speed up in the warm up position either. Have checked the neutral switch it is ok. Have unhooked the teather switch, still starts but only idles. HELP.
