in line 6 no spark

[fish4fun2]

Trying to figure out why there is no spark to the merc model 1500 150hp motor serial #7058125 (canadian)mid seventies motor.<br />I checked the red wire to the switch box and got 12 volts also I turned the key in the on position and checked the white wire to the switch box and got 12 volts.<br />I took off the Mercury switch next to the switch box thinking that this might be the problem, still no spark.<br />My oly guess is that one of these parts are bad (Rectifier, Coil, Distributor) But I am lost on which one it could be.<br />Any information on this mater would be welcome, I have a spare motor same hp same era that I could through on but i have no idea what problems it might have and would like to tinker with this one first.<br />Also the compression on the motor i am working on is.. 130,135,130,130,135,130.

 

[Laddies]

Re: in line 6 no spark

Turn your engine to number 1 and install a spark gap in the plug wire, install a jumper wire between the brn and white wires on the dist side of the switch box, disconnect the blk wire same side, turn the key on and arc the black post to ground. You should have spark on each arc, no spark bad switch box, spark bad trigger

 

[timmathis]

Re: in line 6 no spark

Do as laddie said this will tell you if it is the switch box or the trigger. I had the same problem and it was my dist, or as they call it the trigger! Good luck, Tim

 

[fish4fun2]

Re: in line 6 no spark

Laddies thanks for writing back, I am kinda lost on what your telling me to do, hope this is it...Pull the #1 spark plug and rotate the flywheel until I can see that I am top dead center on #1 piston, then insert something into the plug boot spark plug wire like a screw driver and place it close to the block, then install a jumper wire between the brn and white wires on the dist side of the switch box, disconnect the blk wire same side and do the test...is this right?<br />thanks

 

[Laddies]

Re: in line 6 no spark

Yes, just use a spark plug in the wire, let it rest against the block don't hold it the system has way to much voltage to take a chance--Bob

 

[fish4fun2]

Re: in line 6 no spark

Thanks Bob I gave it a shot and no sparks anywhere but now that I have reread your instructions from your first reply I fear that I might have to do the test again. I jumped the white and brown and brought #1 to TDC pushed a long coated wire in #1 boot and tied the other end close to a ground then I turned the key on and touched the black wire to a ground no sparks. I think I should have ran a wire from a ground turned the key on then touch that wire to the Black Post I will try again tomorrow thanks Jay