My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fish ye

[jorenac1]

Well you guys helped me a lof in my schooling on Merc's, thanks. It is a s/n 4848057.<br />Once I get carb cleaner it will fire, and also when is hot. One engine cools down it won' <br />When it fires with the help of the cleaner, and it runs, I notice it misses at times when I increase speed.<br />I replaced rectifier, carb kits, fuel pump kit, replaced the stator for a used one, I Get tach and volt gage readings, replaced ignition switch, and plugs,disconnected kill switch wire,checked ignition wires for continuity, replaced two; replaced the coil for a new one. Checked the mercury switch to be okay; I get spark on all six.<br />I replaced the switchbox for a used one from the net. No change. Is there a way to check the switch box?<br />It has three wires: black, tan and brown for the triger on one side.<br />On the other side has the red, white and green.<br />The green goes to the ground coil, red for power and white from somewhere out of the plug inside the bottom cowling.<br />I set up all of the iddle timing fro 4 - 6 degrees., carburators throttle closed. Where did I miss ?<br />Do I need a New switch box ? or a triger ?<br />Thanks for your response.

 

[12Footer]

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Switchbox and trigger are fine if you truely have fire on all six.<br />Since you can get it to start on introduced fuel (carb cleaner), it has to be fuel starvation. The only thing you haven't addressed allready ic compression , stuck reed, or exhuast blockage.<br />Compression is the first thing tho. Without it, no fuel being pumped, drawn in, or expelled after combustion.

 

[jorenac1]

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Thanks for finding my questions Admiral.<br />I am so glad to see your comments on my "Murphy's case". <br />I did check compression about three months ago and run between 120 to 125 PSI on all six.<br />I will check it out again tomorrow after work.<br />Just before Memorial day, Decarbbed the Engine after reading some notes in the forum, maybe yours. Shall I run the Decarb again ?. I used Seafoam. Most of it dripped out the prop. exhaust, and the carbs throat.<br />I was wondering if there is an easy way to check the exhaust. I noticed I get water out only from the right top side of column, and the regular Prop. exhaust.<br />About the reeds being stuck, I see the possibility, since when I got it, the intake screen and the Venturi on the bottom Carb. were charred. Did not ocurr to me to check inside.<br />After the Decarb I flushed all ports with cleaner and canned air.<br />To check the reeds, can you give me an idea of what shall I have on hand just in case ?<br />Your comments are always welcommed.<br />

 

[Hooty]

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

When starting, choke the shi* out of it until it starts or floods. My bet is it'll start.<br /><br />c/6<br /><br />Hooty+

 

[jorenac1]

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

I certainly will; I got a full tank sitting waiting. I will try tomorrow eh, eh, eh.<br />Thanks for the tip.<br />

 

[12Footer]

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

With compression numbers like that, I would allmost rule-out reeds, and you problably would actualy hear a stuck open reed as a 'hissing' thru the carb anyway.<br />Hooty probably has your answer, because all outboards like to be choked to death to start the first time.<br />Pump the primer until firm before trying to start it too. With the primer bulbs being proiduced these days, that could be 30 squeezes. They really are junk, and some must be held vertically to even operate the way they are suposed to.

 

[jorenac1]

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

<br /> Guys I think you just got fish with your names on the wall.<br />Just pumped the bulb to firm, choked the shi* the first time, flywheel spinned about 10 second, went gluummmpdt, starter stopped; then tried it w/o the choke, and ahhhh, what an exhilarating moment, soaked with all those fumes until I cried of happiness. My wife was telling me that the fumes were affecting my brain...<br />I will check it out tomorrow again; no much time today. I had to play car mechanic on my old lady's Huuyndai Sonata; the radiator fan quit while waiting for McDonald to cook the shi* fries. Luckily i will have the coolant switch and sensor tomorrow.<br />Hurray for you good teachers. If we had people like you in office, we would be driving boats instead of cars.<br />God bless ya.

 

[jorenac1]

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Yup, It fired again: Thanks so much for all your help.I will take her out saturday if weather is good: so far it looks blllek. I don't have a name for her yet.. I guess it deserves a nice one , after all those names I gave her the last few months. I hope it does not leak.<br />happy fiiishhingg...

 

[andrewkafp]

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Re: My 78 merc 6 cyl in line wont fire w/o carb cleaner; boat not wet and no fis

Ahahhhh <br /><br />I LOVE this site....and the good stories.<br />Can't get this stuff in a book .... <br />or a library...