No Spark..... Continued....

[GLPmike]

Still no spark on my 1968 Johnson 65 hp v4...

Help!

No spark when cranking the motor.

 

[GLPmike]

Re: No Spark..... Continued....

Amp and new coil check okay. Points set at .010 and 0- infinity four times on one rotation, new distributor cap and rotor.

I get spark on all cylinders when rotating cam shaft by hand to align rotor with plug tower.

The only time I do not get spark is when I crank the engine. I used a spark tester on each cylinder and nothing! Something must be going to ground...

I plan on testing the coil wire with the tester today as I crank the motor.

Thanks

 

[GLPmike]

Re: No Spark..... Continued....

Well. Just cranked the motor with the coil wire removed from the distributor to a spark plug tester. Got a healthy white/blue spark consistantly!!!

So, for some reason I am not getting spark out of the distributor to all four cylinders. I just replaced the distributor and rotor with new omc parts! But, I am getting the same results...

Question: what can cause a no spark condition out of a distributor that is receiving a strong healthy spark?

Thanks

 

[GLPmike]

Re: No Spark..... Continued....

Is it possible I have a major timing problem?

I have spark going to the distributor and I have gotten spark testing each cylinder hand turning the cam shaft.

But, when I crank the motor I am not getting spark through the distributor to each of the four cylinders.....

Totally stumpted....

 

[oldrenken79]

Re: No Spark..... Continued....

Try this, see if it works.

I'm running blind here, so if I'm off let me know. Unhook the ground wire from the power pack and use a remote starter switch to crank instead of the ignition switch. If it starts, touch the ground wire back to its conector and that should kill it.

If this works, there's a problem between the ignition switch and the harness on the power head.

At least it was on my buddy's '75 three cylinder Johnson.

 

[F_R]

Re: No Spark..... Continued....

Try this, see if it works.

I'm running blind here, so if I'm off let me know. Unhook the ground wire from the power pack and use a remote starter switch to crank instead of the ignition switch. If it starts, touch the ground wire back to its conector and that should kill it.

If this works, there's a problem between the ignition switch and the harness on the power head.

At least it was on my buddy's '75 three cylinder Johnson.

DON'T DO that! That is a different kind of ignition system. Never experiment with disconnected wires unless instructed to do so on good authority. Blown amplifiers are expensive.

GLP, what spark gap are you using at the plug wires? Have you tested the plug wires for continuity?

 

[GLPmike]

Re: No Spark..... Continued....

Yes. The plug wires are good. Got spark to each cylinder using spark tester to ground while rotating cam shaft by hand with key in on position.

Spark tester is gapped about one quarter inch.

 

[GLPmike]

Re: No Spark..... Continued....

Sorry. Correction, I aligned the rotor to each plug rowen then grounded amp wire and got spark from distributor through each plug wire to tester.

 

[James R]

Re: No Spark..... Continued....

I have the schematic for the 85HP model but I believe it is the same as yours. Are you saying that if you align the cam position such that the distributor cap plug pole is aligned with the rotor and you simulate the points closing by grounding the black/white wire going to the Amp that you get a good spark at the plug. If you are then the problem is with the points set up, insulators, wires.

 

[GLPmike]

Re: No Spark..... Continued....

Points are gapped per spec .010 and I was getting 0- infinity four times on one rotation.

Also, I get excellent consistent spark of the coil wire while cranking the motor. So, the points appear to be working correctly. This is what's strange...

 

[GLPmike]

Re: No Spark..... Continued....

New plugs are Champion QL77JC4 gapped at .030

thanks

 

[GLPmike]

Re: No Spark..... Continued....

F.R. Thanks....

Spark tester gapped at each plug wire is the same gap used to test spark off coil wire when cranking motor. About 1/4". I got a very healthy consistent spark here.

After this test is it safe to assume the points are working correctly?

If so, should I adjust the spark tester to .030 (same as plug gap)?

Please let me know and I can retest tomorrow.

Thanks for you help.

 

[F_R]

Re: No Spark..... Continued....

F.R. Thanks....

Spark tester gapped at each plug wire is the same gap used to test spark off coil wire when cranking motor. About 1/4". I got a very healthy consistent spark here.

After this test is it safe to assume the points are working correctly?

If so, should I adjust the spark tester to .030 (same as plug gap)?

Please let me know and I can retest tomorrow.

Thanks for you help.

If you are getting consistent sparks off the coil wire, the points are at least triggering the amp. Now, the sad truth is that those distributor caps were a crappy design. You could have a great spark going into it, but weak spark coming back out. That is why I asked what gap you are trying to fire. You said somewhere that you got a new cap and rotor, right? They should be as good as you can do, which is still crap by design.

You should get a 7/16 spark off the coil wire and at least 1/4 at the plug wires. Talking about sharp pointed gaps here.

Yes, I suggest closing your tester down to a narrower gap just for laughs to see if ANYTHING is getting through the distributor. If you have 7/16 going in and 1/8 coming out, it is getting lost in there someplace. Hey, a thought just came to mind--you don't have car plug wires on there do you? No good.

One last thought and I'm out of suggestions. A proper spark tester will test all four wires at the same time. Other test methods will give unpredictable results.

Oops, I lied. Still another thought. Maybe you are getting low voltage at the amp input when cranking. Nevertheless, if you are getting 7/16 off the coil wire, one would think it is ok.

 

[GLPmike]

Re: No Spark..... Continued....

F.R. Thanks.

All wires are oem.

When I align the rotor to each plug tower manually and groung the amp wire I do get a strong spark to each plug wire end with the tester set at 1/4.

I will close the tester a bit and retry.

FYI - I have not filled the plug towers on the distributor with an insulating grease as of yet. Is this something I should do at this point while testing?

Is it possible I am having a timing problem?

Thanks

 

[GLPmike]

Re: No Spark..... Continued....

Just measured the gap at largest opening for spark at tester off the coil wire.

5/16 is the largest gap with spark.

Also, how strong should the spark be? It looks to be about 1/16 or less. Is this what I should be expecting?

Thanks

 

[GLPmike]

Re: No Spark..... Continued....

I was able to get 7/16 spark at the coil wire by adjusting the point gap at .012.

I am now getting consistent spark through the distributor and rotor to each plug wire end. With the tester the best I could do was 1/16-1/18 gap for a consistent spark.

Squirted a little fuel mixture in the carbs and it tried to kick over as the starter shut down!!!!

I will give it a water barrel test this weekend....

Thanks F.R. And the rest for all your help!