no spark

[dstarok]

Re: no spark

Thanks all-
I got my hands on a dva tester, now I am reading with that. Now, as before, I am checking for input to switches (output from stator) by reading: blue, red, blue-white and red-white. With these wires disconnected from the switches, I have about 170-180 on the blues and 24 on the reds. If I connect them to the switches they all fall to about 7 -8 volts, and I read no output form the greens (to the coils). I tried unplugging the yellow wires from the rectifiers and no change. The white/black wires which jump between the 2 switch boxes do not go anywhere, there is a wire coming off the terminal on the inner switch box with a white/black wire on it, for about 2 inches then it has a (female) bullet connector on it, obviously where something used to connect, I guess the idle stabilizer or the low speed/high speed spark advance module. Apparently the previous owner or his mechanic didn't feel these were necessary! Along with the tilt switch which is also missing. I personally do not believe in "if its broke remove it it ain't important anyway", but first things first, I will look at replacing these items later.
I also took reading on the trigger wires at the switches as descibed on the troubleshooting procedure by cdi, and only have 2 volts between 2 sets of wires and 1.3 volts between the other, this is with them connected to the switches. Should they be disconnected to take these readings? Would a bad trigger cause my symptoms? I am thinking the stator seems a bit weak, but should still function. It still seems like the switches are both bad, maybe that happened due to a weak stator? Or the bad trigger making the switches not operate.
Also I did look at the magnets on the flywheel, they all seem to be in the correct position.

 

[dstarok]

Re: no spark

OH, also THANK YOU for everyones input, I am really getting a lesson here, painful and tedious because of my limited knowledge, but I am learning alot! Please keep up the great input, I believe with your help I will soon find the answers!

 

[sleepinin]

Re: no spark

If you start on the downstream end and work your way up you should be able to find this. Even though the switch box bias test passed that is not conclusive that the switch boxes are good. Set DVA at 400vdc for all these test. The wires should be hooked up. Pull the switch boxes aprt so you can get to all the terminals, but you must ground the switch boxes so they won't fry. I leave the grounds hooked up and run a jumpers with alligator clips to be sure. By the book you should start at the coils and test between the + and - terminals. With engine cranking you should get 90 - 145, I'm guessing yours will fail this test since you got no output from the greens. Now test (+ probe) on Blk/yel terminal (- probe) on ground. You should get 200 to 300 while cranking engine. if it's above specs the trigger or switch box is bad. If it's below then there's another test you have to do. (let me know if that happens) If it's within spec then test the stator. The first stator test is blue(+) and Ground(-), should get 100-265 at cranking speed. Then next stator test is Red (+) to Ground(-), should get 25-50 at cranking speed. If either of these is low then the switch box or stator is bad. If these are within spec then test the stator again blu/wht (+) to ground(-), should get 100-265 at cranking speed. Then test Red/Wht (+) Ground(-), should get 25-50 at cranking speed. If these are below then the stator or switch boxes are bad. Seems like you were OK on these from your previous post. To rule out the stator do an Ohms Test on the Stator. Remove Blu/Wht and Red/Wht leads from outer switch box. Remove Blue and Red Leads from inner switch box. Set Meter to Rx1000. Between Blue and Red Leads you should get 3500-4200. Between Blu/Wht and Red/Wht you should get 3500-4200. Now set meter to Rx1. Between Red Lead and Black Lead you should get 90-140. Between red/White Stator Lead and and Black Stator Lead you should get 90-140. One of these test should point you in the right direction.

 

[Laddies]

Re: no spark

dstarok, wlth a DVA and meter to use and a CDI/Rapair manual in hand, start your tests over, disreguard any information you have received other than the CDI test and you will find the problem quite simply. YOU have so much advice your drowning in it all.

 

[dstarok]

Re: no spark

Thanks for the replies. Laddies- I am trying the cdi troubleshooting guide and it doesn't get me there, but thanks for the encouragement. Sleepinin, as you expected, no voltage wiith dva at coils. Next was the blk/yel term, I assume you meant off the switch box. I am only getting about 10-12. You said to let you know if that happens. What now?

 

[phatmanmike]

Re: no spark

laddies is a proffesional merc mechanic. he is very good. listen to him.

 

[dstarok]

Re: no spark


Let me clarify, I read the voltage from the Blk/Yellow terminal (with black/yellow wire still connected)
I am only getting about 10-12.(Volts)

One thing that I don't understand is that when the wires are all connected, I read only about 12 volts on the reds and blues, but with the reds and blues lifted, I read about 170 blue, 24 red,
185 blue/white, 24 red/white. Is this normal?

 

[dstarok]

Re: no spark

Phatman, I guess I don't have the manual that he thinks I have, I am using the Mercury service manual, and the seloc repair manual. I downloaded some troubleshooting guidelines provided by cdi, but I don't have a CDI/ Rapair manual. I certainly wasn't trying to diss Laddies, I hope it wasn't percieved so. I have symptoms which my "manuals' don't seem to address it seems.
Thanks,
Dave

 

[Laddies]

Re: no spark

Dave,I guess I should have said this along time back but I belive it is much better to let someone to learn how to test a system themselves once you learn how it works in the future it will be much easier to repair. Just a few rules of thumb for your system.

No spark any cyl.= shorted kill system-disconnect the black yellow wire at the switch box, no spark diconnect the yelow wires at the rectifier still no spark still on any cyl=stator- test stator output at the box blues are 180+ and reds are 30+ volts (your reds are a little low, disconnect them from the box and retest.

No spark on one bank or odd and enen number cyl. on a inline = switch box / swap red to the red white an the blue to the blue white terminals if the spark changes sides its the stator and if it stays the same it's the switch box.

No spark on 1+2 or 3+4 or 5+6 its a trigger

I hope this is not to confusing to you, try to remember that the stator has 2 functions it produces all electricity for the engine 12+ volt to charge the battery (2 yellow wires) and a low speed winding for the startup and idle (blue and blue white wires) plus the high speed winding (red and red white wires) that are for high speed running. The trigger on your engine tells ithe switch boxes when to fire the system and is made up of 3 windings each only effects 2 cyls. 1+2 or 3+4 or 5+6, a shorted rectier can cause a internal short in the stator and kill the whole system--Bob

 

[dstarok]

Re: no spark

OK well I agree with you there,I won't forget this lesson. I think I figured it out, I was getting on here to announce it when I read your last post. Since I don't have a tilt switch, and I had the 8 pin connector unplugged, I figured that the kill "circuit" wasn't the problem. I read the black/yellow wires to ground, had no continuity. From then on I was past the kill circuit as the problem.
I was taking more measurements, and as I have posted I had more than one which was outside of the specs, triggers at 2 volts insead of 4, with the blue lifted the readings were kinda weak, around 170 on one lead, reds were only about 24. When the blues were landed, they only read about 12 volts. Nothing that was glaringly wrong. But I decided lift the black/yellow wire form the switches and read to ground again to make sure there wasn't a short in the kill circuit. There wasn't. But then I measuring off the blue/white while it was still landed on the switch, but the black/white wasn't. 180 volts on the blue, good voltage on the greens, eureka lol. It seems that the inner switch box is bad, and when it is connected via the black/yellow to the outer switch box it makes them both have no output.
Again, my mistake was thinking that the trouble with the kill circuit would either be the key switch, harness, shift wires or tilt switch and since these were not in the equation, I missed the connection between one switch being bad affecting the other.
The mechanic replaced the outer switch box a couple months ago, guess we shoulda changed both of them. I am ordering 2 cdi-radair switches to replace both, will keep the 2 month old OEM switch as a spare. If I have any more trouble after replacing these I'll re-post, but I am pretty certain this should do it!
THANK YOU ALL for your help and efforts and patience!
DAve

 

[sleepinin]

Re: no spark

Dave,
Since your Blk/Yel was low you need to disconnect the Blk/Yel from both the inside and outside switchboxes and test again. Test the terminal not the wires. If reading is still below spec you've ruled out the ignition switch and wiring. If reading is in spec your motor may start and you should think about how your going to shut it off without the key. :%

 

[sleepinin]

Re: no spark

I should of refreshed my screen before I posted. Congradulations!

 

[dstarok]

Re: no spark

Well if nothing else, at least I am persistant huh?:|
Thanks again.

 

[Fozj]

Re: no spark

Laddies, I have a inline 4 cylinder 40 hp That does not fire on number 1 plug other 3 ok. I have swapped wires from the switchbox to the coil and the spark moves to number 1 plug. If I swap the stator wires as you describe below will this let me know if I need a switch box or stator. I am not sure what you mean by "one bank or odd and even number cyl"
Thanks Foz
[quote time=1156116987 user=Laddies uid=49545

No spark on one bank or odd and enen number cyl. on a inline = switch box / swap red to the red white an the blue to the blue white terminals if the spark changes sides its the stator and if it stays the same it's the switch box.

 

[Plainsman]

Re: no spark

Fozi, Welcome to iBoats. How did you check spark? With a tester or holding the plug to the block?

You may want to start your own thread for this. Just my opinion.

 

[Fozj]

Re: no spark

I checked the spark by clamping all 4 plugs with jumper cables and grounding cables to block.
Fozj

Fozi, Welcome to iBoats. How did you check spark? With a tester or holding the plug to the block?

You may want to start your own thread for this. Just my opinion.

 

[fourth and long]

Re: no spark

hi,
i own a 1981 merc 25 hp outboard serial no.--------------
5822477
i was told that the cd pack is bad. what actually is a cd pack? can i order this from you? if so, can you tell me
the price + shipping? the former owner left the ignition
switch on for 2 days and probably ruined the pack. is
this possible?
please let me know via email.
email knagle2288@aol.com
thank you kindly,
ken nagle.