Troubleshooting Help: Ignition Switch on Older OMC

[Pmccraney]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Friends:
In lieu of scattering the board with a new thread, I figured I would revive this one for some additional trouble-shooting help. As you can see from the video below, I have resolved the starting issue and appear to be on a good start for wiring up my boat.

Yesterday, I put the motor on muffs, primed the bulb with some fresh 50:1 gas/oil and went to see if I could crank her. The starter engages and the fly wheel spins, but she just doesn't want to fire up and come to life...

I read the manual and I think I can eliminate most of the issues that can cause a no start:

(1) Shifter in neutral - check.
(2) warm up lever in "start" position (even adjusted the cam roller on the carb to line up correctly).
(3) fuel pump filter has been inspected and there is no blockage there.
(4) I have brand new fuel lines throughout - including new lines from the fuel pump to the carbs.
(5) fuel bulb is fully primed and getting gas to the fuel pump.

Unless you guys recommend trouble-shooting other areas first, this is what I am suspecting:

(1) continued problems with wiring the starter circuit -- (might have the engine kill wired wrong keeping me from firing up).
(2) My choke solenoid is acting up - the choke plunger was only diving down into the solenoid a couple of times. However, I manually closed the choke valves to try and get it to start and that did not help. I will have to resolve that, though.
(3) I changed out the spark plugs. I used the "gap" from the prior plugs with a gap measuring tool, but that could be a source of trouble (I am going to buy a spark tester and make sure I have spark and can jump the recommended 7/16 gap this afternoon).

Other thoughts or potential problem areas to look into?

 

[classiccat]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Hey Patrick,

the kill switch (grounding the powerpack black/yellow) could be the problem. Select the pair of terminals that have continuity when the lanyard is out (or you press the kill button).

Regardless, definitely proceed with troubleshooting your spark. You want maximum RPMs for this test...at least 300. You may need to relieve cylinder compression by removing the spark plugs. Disconnect the fuel line and drain the float bowls...you don't want fuel blowing out of the plug holes especially when you've got sparks firing. I also ground the coils that aren't being tested. Lastly, you can disconnect the harness completely and test the motor's ignition components by wiring-up a single-pole switch to activate your solenoid.

Here's my setup for testing spark on a 3cyl 70hp...rubber-band makes it momentary :lol:

 

[classiccat]

Re: Troubleshooting Help: Ignition Switch on Older OMC

by chance is the bad rectifier still hooked-up?

 

[Pmccraney]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Thanks Chris. The bad rectifier has been replaced. I don't have a separate kill switch installed. I was just referring to the "kill circuit" terminal on the starter switch itself (black with yellow stripe on one of the "M" terminals).

Nice little switch you have there. Yes, I am guessing I could jump the solenoid (see below, I did that when troubleshoot my starter and solenoid (earlier in this thread). See the funny video below (it sort of scared the crap out of me the first time I did it):

Assuming I've got good spark, that might isolate the problem to the starter switch wiring (and potentially the choke problem)??

As always, thanks for your help!

 

[Pmccraney]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Okay gang:

Quick update. So, I bought a spark tester on the way home from work today. Set it at 7/16 gap, had my son turn the key - Nothing, no spark on all 4 plugs...

However, I was able to bypass the the whole starter/power pack by unplugging the red plug and jumping the solenoid.. I manually closed the choke with a sharpie pen and it wanted to come to life but would quickly die... So, I removed said trusty sharpy pen so the engine could get some air and she fired right up:

So, I'm guessing the problem is in the control box? I'm killing my spark somewhere...

 

[classiccat]

Re: Troubleshooting Help: Ignition Switch on Older OMC

i'm curious... how did you stop the engine :lol:

I'm not sure how much help I can provide with your choke issue(s). I believe electrically is functioning properly (pulling-in when activated)...it might be something with your choke linkage. Is there a lever near the choke linkage for setting the choke control (manual/automatic/off?) Also, how many wires does your choke solenoid have coming out of it...you may have a 2-stage choke.

Is your temperature switch (tan wire) still dangling or did you connect it back to the buzzer?

 

[Pmccraney]

Re: Troubleshooting Help: Ignition Switch on Older OMC

i'm curious... how did you stop the engine :lol:

Its still running... (just kidding)... I actually scratched my head for a few minutes and then I just closed the choke, starved her for air and she died...

I'm not sure how much help I can provide with your choke issue(s). I believe electrically is functioning properly (pulling-in when activated)...

Its actually not pulling in when activated... It did it a few times when trying to start it yesterday, but it only worked very intermittently (maybe about 2 out of 20 times).

it might be something with your choke linkage. Is there a lever near the choke linkage for setting the choke control (manual/automatic/off?) Also, how many wires does your choke solenoid have coming out of it...you may have a 2-stage choke.


There is a choke lever (little cam looking thingy) on the starboard side of the carb, but there is no lever attached to. There is a hole on the front of the motor (just below the cowl that says "choke" but there is nothing in there (i.e. no manual choke push attached to the lever). Solenoid has got 2 wires coming out of it... Plus a little ground wire wired to the stud where it attaches to the intake.

Is your temperature switch (tan wire) still dangling or did you connect it back to the buzzer?

Yes, it is reconnected to the buzzer...

 

[classiccat]

Re: Troubleshooting Help: Ignition Switch on Older OMC

If i were to ever try to run w/out the red harness connected, I'd rig-up a kill switch at the engine.

That sounds like a 2-stage choke; search the forum but I believe there's a service bulletin on making it operate as a 1-stage (tying to the 2 purples together? :noidea It might be a loose connection somewhere; double-check your connections to make sure they're tight. Also, when it's not working, check to see if you're getting 12V at the solenoid (terminal strip) when you're trying to activate it. If you're getting 12V and it's not activating, you may need a new choke solenoid if both the linkage and solenoid installation is correct.

Take a close look at the linkage for the manual choke. Even though you're missing the manual lever, there may be a piece that's obstructing activation...test by manually moving the solenoid plunger and watch the choke butterflies. Lastly, you may have the solenoid installed in the wrong position (too far in/out of the bracket). The FSM shound have instructions for the correct solenoid position.

I recall that you installed a new ignition switch. Start your spark tests w/ the red-hardness connected (and fuel line disconnected). CDI troubleshooting-Page35. I have a hunch you'll find the canary at step-1.

 

[Pmccraney]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Blue Fin; You have been a huge help (I really appreciate it)...

For those just tuning in, we have two issues: (1) no spark on all 4 cylinders when starting from control box; and (2) choke is acting up.

(1) No spark issue:

At this point, my best guess is that something about the way I wired my key-switch was killing my spark... (given that I had no spark on all 4 cylinders. My manual says: [No spark on all 4 cylinders, check: 1) sensor coils; 2) charge coils; 3) power pack; 4) key switch and 5) 10-way connector...] However, since I was able to get the motor to run for about 5 minutes by by-passing the control box, I am thinking the "canary" as blue-fin calls it, might be No. 4. However, I appear to have it wired correctly, per the diagram below I found:




So, one or other option is that I may have had a faulty neutral start in safety switch (I will be installing a new one anyway, because one of the terminals broke when I was trying to remove it the other night). I'll start by re-wiring the the control box with the new choke switch and new start-in-safety neutral switch... If that doesn't fix it, I guess I'll have to buy a DVA/peak reading voltmeter and start checking some of the major ignition components.

On the choke issue, I made some interest discoveries (see next post):

 

[Pmccraney]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Part 2 (choke):

(1) First, the choke solenoid appears to be functional. I did a resistance test with the multimeter and the ohms were within the range of the manual.

(2) However, in attempting to find the "lead" for the purple/yellow stripe wire (when doing the ohms test), I discovered that the wire had been cut (see below):



Below is where this lead should have connected on the terminal board (but is missing).



I suspect that someone monkeyed with it trying to make it a one-stage choke (because both purple wires on the choke switch - at control box - were wired to the same terminal).

I am not sure why they did that because I tested the thermo switch that works hand-in-hand with this appears to be working (I got a closed circuit at cold on a continuity check; haven't been able to see if the circuit opens at 100 degrees).

So, I'm really not sure what I am going to do (re-wire it as it was originally intended, or maybe the modifications are preferred for some reason???). Curious what you guys think.

sorry for all the "words" but I am trying to be detailed.

 

[Pmccraney]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Guys: I think I fixed it, so I'll leave you guys alone now .

I rewired the control box this a.m., tested all of my switches, etc... turned the key and she fired right up... Chokes still not working, but I think it has something to do with the cut wire, etc..

I'll let you guys know the choke solution if and when I ever figure it out. Can't Thank you Guys enough for your help!!!

 

[TrueNorthist]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Good news! Wiring is often a case of returning to work you think you already fixed and noticing a problem that got missed. Not seeing the forest for the trees kind of thing. I would also strongly recommend you delete any and all crimp connectors once you have determined that the wiring is correct and soldering and shrink tubing everything. Oh, and remember to take a kicker with you on the first trip.

Edit: did you try to hotwire the choke to make sure the solenoid is working? If it is then jump the wires at the switch. If it works then the switch is bad. Wires must be disconnected from the switch for these tests. Any single throw DC switch will do but I would get a stainless one with a spring loaded, normally open throw.

 

[seahorse5]

Re: Troubleshooting Help: Ignition Switch on Older OMC

The bulletin back then had the tech put both choke solenoid wires on the same terminal as the purple-white wire from the key switch. That bypassed the semi-auto feature and the troublesome temp switch it used. Now you have a regular choke that will activate when the switch is toggled.

That solenoid required both wires to be energized to pull the choke plates fully closed while the engine cranked over.

 

[Silvertip]

Re: Troubleshooting Help: Ignition Switch on Older OMC

Just a reminder that should you ever end up with a no spark situation, the problem will NOT be the neutral safety switch or that circuit. The neutral safety switch merely prevents the starter from engaging when the control box is in forward or reverse gear. That switch has nothing to do with the actual ignition (spark) circuitry. It is the "kill" switch (which you don't currently have) that kills the spark.

 

[Pmccraney]

Re: Troubleshooting Help: Ignition Switch on Older OMC

. I would also strongly recommend you delete any and all crimp connectors once you have determined that the wiring is correct and soldering and shrink tubing everything. Oh, and remember to take a kicker with you on the first trip.

Yeah, those existing connections were just place holders... I've already redone them!!

Edit: did you try to hotwire the choke to make sure the solenoid is working? If it is then jump the wires at the switch. If it works then the switch is bad. Wires must be disconnected from the switch for these tests. Any single throw DC switch will do but I would get a stainless one with a spring loaded, normally open throw.

I tested the switch by hooking up the leads to my continuity tester...I got a close circuit (beep) when lifted the switch, so I'm assuming the switch is operable... I also did an ohms test on the solenoid by checking the leads, and I got the Ohms readings per the manual, so I'm not quite sure what the deal is... By-passing the switch seems pretty self-explanatory, but for some reason I'm still a little fuzzy on how you hotwire the choke? I'm all for further troubleshooting, though...

The bulletin back then had the tech put both choke solenoid wires on the same terminal as the purple-white wire from the key switch. That bypassed the semi-auto feature and the troublesome temp switch it used. Now you have a regular choke that will activate when the switch is toggled.

That solenoid required both wires to be energized to pull the choke plates fully closed while the engine cranked over.

Got it! Thanks for letting me know. I think they tried to do that, but they didn't hook up both solenoid wires to that terminal (they just cut off the one (purple yellow) that mated up to the problematic thermo switch terminal - and didn't really change anything else).

Just a reminder that should you ever end up with a no spark situation, the problem will NOT be the neutral safety switch or that circuit. The neutral safety switch merely prevents the starter from engaging when the control box is in forward or reverse gear. That switch has nothing to do with the actual ignition (spark) circuitry. It is the "kill" switch (which you don't currently have) that kills the spark.

Thanks Silvertip.. That actually makes perfect sense now that you say it.

I really appreciate everyone's help... I still have light years of learning to do, but you guys have helped me understood a lot more about how this motor works.

 

[TrueNorthist]

Re: Troubleshooting Help: Ignition Switch on Older OMC

When I say "hot-wire" I mean just run 12v to the solenoid directly and verify that it works. Do you have 12v at choke switch when the key is on? (A test light would be very usefull at this point) Do you get 12v at the solenoid when the switch is activated? (Again, key on)