1980 115 Adjust carbs!!!!??????

[markmac]

ok i had issues with the engine going dead after running awhile, i have rebuilt the carbs and the fuel pump. at WOT it will run fine for a few minutes then try to die, i pump the throttle to keep it from dying and it will keep running. before i rebuilt the fuel pump it would just die, pumping throttle or not. so my next question is are my carbs not adjusted correct. i had saw a post that said to run screw all the way in an then turn out 2 turns . the engine runs rough, skipping during a high idle,1500 rpm maybe. so i turned the screws in about half a turn an the engine seem to smooth up a bit. are the screws with the spring inside the only screws you adjust on the carbs? i have WMK type carbs. thanks for any input.

 

[Laddies]

Re: 1980 115 Adjust carbs!!!!??????

Yes, those are the low speed needles and they are the only mixture adjusting screws on the carbs. The high speeds are a fixed orifice, did you clean them? The mixture is also controlled to a degree by the float levels did you check that? If the carbs are right check the Max spark advance to much advance will cause pre ignition and overheat a engine or burn a piston.

 

[hkeiner]

Re: 1980 115 Adjust carbs!!!!??????

i pump the throttle to keep it from dying and it will keep running.

I am not quite clear on what you are describing overall, but if the motor is running only while squeezing the fuel bulb, then the likely culprits are a bad fuel pump or a restriction in the fuel line. This can be determined using a vacuum gauge on the fuel line, as per the below guide.

If these tests show no problem, then it is also possible that a gummed up carb or miss adjusted float are causing the problem and the extra pressure from squeezing the bulb is overcoming this.

 

[markmac]

Re: 1980 115 Adjust carbs!!!!??????

Yes, those are the low speed needles and they are the only mixture adjusting screws on the carbs. The high speeds are a fixed orifice, did you clean them? The mixture is also controlled to a degree by the float levels did you check that? If the carbs are right check the Max spark advance to much advance will cause pre ignition and overheat a engine or burn a piston.

how do i check max spark advance and float levels? and yes i cleaned all orfices throughly when i rebuilt carbs. thanks for all your help.

 

[markmac]

Re: 1980 115 Adjust carbs!!!!??????

I am not quite clear on what you are describing overall, but if the motor is running only while squeezing the fuel bulb, then the likely culprits are a bad fuel pump or a restriction in the fuel line. This can be determined using a vacuum gauge on the fuel line, as per the below guide.
QUOTE]
sorry if i was not clear hkeiner. i do not have to keep pumping squeeze bulb,i have a hot foot and i keep pumping it. i just rebuilt all carbs and fuel pump.

 

[Laddies]

Re: 1980 115 Adjust carbs!!!!??????

You need to start your repair with getting a OEM service manual. To time the engine start by running the fuel out of the carbs, if it starts while timing it you will really have a problem. Next you need a remote start button and timing lite, with the light hooked up put the engine at WOT, turn the key to on and use the start button to crank the engine WATCH the prop as it will be turning, losen the max spark advance screw and set the timing to 21 degrees BTDC. Here's the float adjustment.

 

[markmac]

Re: 1980 115 Adjust carbs!!!!??????

here is an update on whta i found to be the problem. it was the rectifier. thanks for all your help guys, i could not have gotten my boat to run good without yall.