no spark

[roxi]

have 1981 80hp mercury with no spark #4 cyl swapped coil #3 and#4 STILL NO SPARK #4 but had spark #3 this tells me coils are good so I assume switch box is the problem or could it be something else.

 

[CharlieB]

Re: no spark

You are most probably right as if it was a trigger you would have lost two cyls, not one, and a stator would loose all cyls.

HOWEVER, since there is NO RETURN on electrical parts, I always highly recommend DVA testing to positively PROVE the fault before ordering any part.

 

[1nebel0]

Re: no spark

Charlie is right about testing however it should be the switchbox..had the same thing today and it was the box...most common thing to go on Merc's...than stators....just my 02....

 

[1970Thunderbird]

Re: no spark

Roxi,

I would be very interested to hear what you find out, as my '78 80hp is doing the same thing. I checked all my wiring, ran new ones, am using new coils, swapped them, etc. I, too, think it's the box, but I was hoping you might be able to confirm that replacing the box fixes the issue. I'd love to hold onto that $200 if I could.

Thanks!

 

[roxi]

Re: no spark

Hi thunderbird I am looking into used switch boxes since the least expensive I've found is the sierra at 180.00plus shipping I will post results soon. Another question for you my motor had trouble at idle and would stall some times but it would accelerate fine and seem to run good once it was up on plane,does this sound like the way your motor acts.

 

[1970Thunderbird]

Re: no spark

Roxi,

No, my motor idles fine and runs up smoothly. Heck, the only reason I even discovered that my number 4 wasn't firing was I was messing around and put my digital tachometer lead on the number 4 wire and it flashed zeros, meaning it had no reading. I removed the plug wire with no change. Another indicator was a lot of oil in my test tank.

If I were you, I'd put a timing light to your motor. It could be that your idle pickup timing is off by a few degrees, but your wide-open timing is correct. That could be a cause for your motor. It could also be that your motor is idling a bit too low. Mine will stall out if I try to idle it too low.

 

[1970Thunderbird]

Re: no spark

Roxi,

I just replaced my switch box. I can't even begin to describe how much better the engine runs now. I can get my idle to normal ranges and am getting great spark to all cylinders, including 4 which used to have no spark.

I, personally, would be a bit wary of used electronics. I bought my switch box from Amazon. I have Prime, so I ordered it Saturday and got it Tuesday. Just put it on.

Here's a link. They had it the cheapest of any place I'd seen

http://www.amazon.com/gp/product/B00027GPDW/ref=oh_details_o00_s01_i00

 

[chum1]

Re: no spark

Looks like there are 3 choices for these powerpacks:

1) OEM 332-5772A7
2) Sierra 18-5881
3) CDI 114-5772

I changed my stator and trigger on my 77 850 long ago with used cdi components from ebay and its been running great since but thats a matter of preference, merc. electrical parts are way overpriced compared to older johnnyrudes i have found but seem to be edging down.

 

[1nebel0]

Re: no spark

There are 4 choices...Mallory...you can buy that for $130 and they are made in Germany...half the price of Merc and in my opinion better. Sierra doesn't make theirs nor does Teleflex...

 

[roxi]

Re: no spark just to up date my problem

Re: no spark just to up date my problem

Roxi,

I just replaced my switch box. I can't even begin to describe how much better the engine runs now. I can get my idle to normal ranges and am getting great spark to all cylinders, including 4 which used to have no spark.

I, personally, would be a bit wary of used electronics. I bought my switch box from Amazon. I have Prime, so I ordered it Saturday and got it Tuesday. Just put it on.

Here's a link. They had it the cheapest of any place I'd seen

http://www.amazon.com/gp/product/B00027GPDW/ref=oh_details_o00_s01_i00

thanks for the info replaced my switch box and took it out on the water yesterday now running on all 4 cyls. and running great