1971 4hp Merc no spark need help with testing results

[Outboard Mike]

Re: 1971 4hp Merc no spark need help with testing results

Assuming the tester is backwards suggests that the stator is ok and the new coil, spark plug,and HT wire eliminate the other potential problem areas. There is a short wire that runs from an engine ground to the throttle plate and looks like it is designed to float as the throttle is advanced. The wire pivots on the top of the bolt. Should this be connected to anything else???

 

[Laddies]

Re: 1971 4hp Merc no spark need help with testing results

The short wire should go from the timer or point housing to ground, if it is not hooked up and the timer housing is not grounded the engine will not have spark. Also while your turning the engine over with the drill use with the jumper wire that replaces the wire that goes to the points I should have told you to tap it on ground not to clip on a ground.

 

[Outboard Mike]

Re: 1971 4hp Merc no spark need help with testing results

Should this wire go right onto the contact points connector??

 

[Laddies]

Re: 1971 4hp Merc no spark need help with testing results

I can't really remember but I don't believe it goes on the inside of the housing 1 goes on the throttle link #37 and it looks like a second one goes up and fastens onto the area that the carb. actuator #10 cam fastens. Here's a link.
http://www.ishopmarine.com/ishop/js...cCatFilter=MM&eCatSupFldr=supplier-050-025-MM

 

[Outboard Mike]

Re: 1971 4hp Merc no spark need help with testing results

Finally got spark!!!I tried the jumper wire from the coil and turned the motor over with the drill and tapped the wire on ground and got a good spark. I had previously tightened up the ground wire from throttle link and the housing assembly and tried turning over the motor but there was no spark. I tested the points wire from the coil to the point stud and got a good reading. Does that mean i've got a points problem?? I disconnected the points wire to the coil and hooked my tester between the coil and the wire and turned the flywheel by hand. The meter moved as the points were opening and closing. What can it be???

 

[Laddies]

Re: 1971 4hp Merc no spark need help with testing results

Its either the point stud insulator or the points probably the insulator

 

[Outboard Mike]

Re: 1971 4hp Merc no spark need help with testing results

It looks to me like the points are grounded properly with jumper wire going from the Throttle plate to the stator base. Is there a way to test if the ground is working?? When I spin the flywheel with tester in line to the points wire to the coil and the meter moves as the points open and close this tells me the points are opening and closing. How can you determine if the points stud insulator is possibly bad???

 

[Laddies]

Re: 1971 4hp Merc no spark need help with testing results

If the point wire shows the points opening and closing the points are probably OK and it the insulator block the boints are high voltage points and the is about 150+ volts to the so the insulator block won't show a short with a OHM meter because it take the high volts to arc to ground or if the point wire is cracked it will do the same thing. You should be able to check the ground to the timer casting with a OHM meter, in fact if the points are showing continuity at the coil the timer must be grounded or it would not read.

 

[Outboard Mike]

Re: 1971 4hp Merc no spark need help with testing results

I'll go out and buy an insulator tomorrow and put it in. Thanks for all your help. I'll let you know the status after installation.