1987 omc 3.0 starts cutting out at 2800 rpm's

[starcar331]

i have a 1987 omc 3.0 has everything new from filter to spark plugs, cap and rotor, electronic ignition, coil. but it cuts out and acts like a spark plug or wire hit and miss it had the same problem before all the new parts were put in with one thing differant it does run a little better with the electronic ignition system but still cuts out! anyone have any ideas on how to fix this problem? would appriciate any help.<br />Ron

 

[Don S]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

Take it for a test run, with a friend. When under way, disconnect the ESA module. Make the run and see how it works. Hook it back up before trying to put it back into neutral.

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

i had tried that but it still does the same thing! i was thinking about the carb adjustment but don't know what the settings are, i appriciate the input<br />Ron C

 

[Don S]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

Are you saying this is an occasional miss? An example would be running along at 3500 rpm and occasionsally there is a quick miss, or is the engine just not going over 2800 and sputtering?<br />Tere are no external adjustments on the carb for high rpms other than adjusting the throttle cable to make sure the throttle plates are full open.

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

no, as soon as it gets to 2800 rpm's it starts cuting out all the time! have you ever experianced a vehicle with a bad spark plug wire bouncing around it will hit and miss constantly off and on but at differant intervals it will cut out and for just a second it will run smooth then cut out again!

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

on the carb. base there are 2 gas mixture screws if i knew how much the turns were that might help<br />i don't know if it's running to lean or not

 

[Don S]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

Those mixture screws are for the idle circuit only and have nothing to do with your problem.<br />Have you done a compression test, and run a vacuum test on the engine to see if they are ok?<br />That would be the first step.<br /><br /> http://www.boatfix.com/merc/Bullet/97/97_25.pdf

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

no, thats one thing i have not checked i will check them out today. thanks will let you know what happens!<br />Ron C

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

just wnet out to the boat and didn't find any vaccum lines at all and what i thought was an esa is aperantly the ignition module on the back side of the throtle linkage plate on the side of the engine, it has cable shift!

 

[Don S]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

Item #71 is the ESA module. The ESA is used with cable shift, all it does is stops ignition to half the cylinders when you are coming out of gear.<br /><br />

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

i will check the compression to see how it is on each cylinder, i use to have a garage and worked on cars for 30 some years, became disabled 6 years ago but still have a lot of my tools the setup on these boats are a bit differant from what i am use to, so the help is greatly appriciated!<br />Ron C

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

i printed out the diagrahm, i think this will help! thanks.

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

there is one other thing, will this module also cause it to be hard taking it out of gear?

 

[Don S]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

Absolutely..........

 

[starcar331]

Re: 1987 omc 3.0 starts cutting out at 2800 rpm's

thank you very much, that was the answer to my entire problem! hope you have a great holliday season<br />Ron C