1974 merc 150 spark issues

[Muppet]

Checked the coil and it's not the coil, we put a differnt switch box in, one out of a 4 cyl, should still atleast give a spark right? It has a differnt distrubuter in it, not a new one. Worked ok last year, pulled it out of the garage this year and nothing. <br /><br />I still have a old distro sitting in the garage that does not spin right. <br /><br />What else is there that I can check to see if I have spark? <br /><br />Is there a way to check the trigger switch to see if it works ok?<br /><br /><br />Nick

 

[timmathis]

Re: 1974 merc 150 spark issues

Go here and it will tell you how to test your trigger.Go down to troubleshooting mercury battery cd ignition section.<br />If you need more help just ask. <br /> http://www.outboardparts.com/troubleshooting/printguide.htm <br />Good Luck, Tim

 

[timmathis]

Re: 1974 merc 150 spark issues

I'm not sure if that switchbox will work. Need part# to tell. Tim

 

[timmathis]

Re: 1974 merc 150 spark issues

Your old trigger still may be good the part that goes bad is made in the housing if the shaft is bad you could change the housings over.<br /> You can test it off the motor just wire it to the switchbox ground it and turn it by hand and if it is good it will make it spark if is good.<br />Tim

 

[Muppet]

Re: 1974 merc 150 spark issues

What is a battery CD? <br /><br />Also I need a new battery for the boat, mine won't take a charge =(

 

[Laddies]

Re: 1974 merc 150 spark issues

All I/6 with CD ign. and with a distrubuters are Battery powered CD. All switch boxes on 4 and 6 cyl engines are interchangeably as far as spark but if the engine is equiped with a tack that reads off the box it will not read properly. Hook a jumper wire between the red and white posts on the box to see if the problem is the wiring or in the engine

 

[speedreel]

Re: 1974 merc 150 spark issues

Also check to see if you have a mercury cut-off switch, and if you do, make sure it's in the right position. I suddenly lost spark on my '76 500 and it took a while to figure out that the hold-down screw for my mercury switch loosened up and the switch fell out of position. Readjusted the switch and she fired right up!