Kill Switch, no spark 73' 85hp Johnson

[F_R]

Re: Kill Switch, no spark 73' 85hp Johnson

You don't have to pull the flywheel to just look up underneath it. I agree the battery should be plenty, but that does not rule out connections and cables, or the starter itself. My point is before you go spending a lot of time on that area, at least rule out the charge coils. Your story is a classic that we heard many times over, back in the '70s. It is supposed to fire at a minimum of 200rpm (even when hand cranking) but it just won't do it if the charge coils are weak. Then you have to crank it faster to make up for it.

 

[rbbrox]

Re: Kill Switch, no spark 73' 85hp Johnson

Last note from me for the day: 700 CCA is plenty. Put the trickle charger on it. Check the battery cables as indicated by others.

Well, so sorry I gave you bogus info. The battery I bought is only 550cca.. Do you think it is too weak to turn 300rpm it only seems to be doing about 200r's so I have it on the charger until full charge and I'll try it again.
Also a buddy of mine suggested running 2 deep cell 6v batteries in series, he said not only will they last longer but they are more powerful, " I don't know"

I guess the real question is, will I get more rpm's with a higher CCA battery?

Thanks for your patients..

 

[rbbrox]

Re: Kill Switch, no spark 73' 85hp Johnson

rbbrox.....Dealt with the exact same thing on my '76 115hp. Bought it from a shop, and instantly started having "trouble" starting. Troubleshot a little myself, before I found what I thought was the problem, when I found no spark while cranking, and then after I would keep trying, it would fire off and then be OK, for the rest of the day. This was on a brand new battery also.

Took it back to the shop a week later and they threw the charger on the battery, flipped it to the 50amp engine start mode, and then cranked the cold engine....started up in about 3 turns, fired right off.

They told me the same thing, that these particular engines really need to crank to turn over.

The charging system on these older V4's is realtively weak, they charge at about 6amps since they are un-regulated, so you really need to charge your battery up everytime you get home or before your gonna hit the water. Once I started charging the battery, I had no more problems. Which makes me wonder how it would ever charge 2 batteries in parrallel. Guess you'd have to manually charge both.

On a side note, through some research, I have found that these old un-regulated charging systems were obviously designed a long time ago, back when batteries were made a lot tougher and used more lead and provided more resistance in the circuit. They tend to run higher voltages with newer batteries, as they don't provide as much resistance in the charging circuit.

Mine was charging at about 18+V at WOT, and was at about 16V at idle. This wil eventually shorten the life of your battery and could do a job on any electronics on board. I installed a regulator off a later model V4, thanks to the generosity of a fellow iboats member who had one laying around.

So I would monitor the charging voltage on that engine too.

Its nice to know I'm not alone. I hope this is the problem with mine. But know even messing with it for an hour and with adding the jump box, I still am not getting spark.
Wish me luck and thanks for the input.

 

[DJ]

Re: Kill Switch, no spark 73' 85hp Johnson

ezeke,

I saw your reference to connections. I reiterated it for a reason. Nobody ever thinks it's that simple so they ignore the advice, more than once. We're on the same page.d

rbbrox,

Follow FR's advice. I forgot about the charge coils. It;s easy enough to eyeball.
But 550 is pretty small for a cold engine.

 

[tashasdaddy]

Re: Kill Switch, no spark 73' 85hp Johnson

i've gotten to where i use a group 27 1050 starting battery, on all my motor, only about 15.00 more.

 

[alden135]

Re: Kill Switch, no spark 73' 85hp Johnson

Like said above, if you're using the original 1973 cables, regardless of what the ends look like, you can bet they're junk. I've had that same problem. They look good on the outside but......

 

[rbbrox]

Re: Kill Switch, no spark 73' 85hp Johnson

I'm going to buy another battery for this old cold blooded little fella and new cables. Was wondering if someone could recommend battery size to get the r's up fast enough to create a spark.
thanks

 

[DJ]

Re: Kill Switch, no spark 73' 85hp Johnson

You're at 550 now. 750 to 850 would be more than adequate.

 

[Silvertip]

Re: Kill Switch, no spark 73' 85hp Johnson

As I said earlier, install the largest capacity (not necessarily the largest physical size) marine starting or dual purpose battery you have room for. The cost difference is insignificant in the grand scheme of things. As you are finding out, you cannot go too big on capacity when purchasing a battery. You can only go too small.

 

[rbbrox]

Re: Kill Switch, no spark 73' 85hp Johnson

ok, new cables, new cranking batt 800cca, new power pack, checked all grounds, wiring looks good no cuts on insulation, under flywheel has no leakage of any kind. I had a auto mechanic look at it who told me I had power going into the power pak but not coming out, that why I thought I had it licked but, no spark.........
ANY LAST SUGGESTIONS would be great.
Have a wonderful holiday weekend.

 

[ezeke]

Re: Kill Switch, no spark 73' 85hp Johnson

Disconnect the Black and Yellow Kill Wire at the power pack to make sure that your new power pack is not being turned off by a bad ignition switch or a short..

Note that If the motor runs you will have to choke or disconnect the fuel to turn it off.

 

[rbbrox]

Re: Kill Switch, no spark 73' 85hp Johnson

Disconnect the Black and Yellow Kill Wire at the power pack to make sure that your new power pack is not being turned off by a bad ignition switch or a short..

Note that If the motor runs you will have to choke or disconnect the fuel to turn it off.

when I disconnect that black and yellow stripe I have no ignition. But, when I put a test light on the 1 term which is the ignition term and crank it I get a strong light pulse.

Note: have been tinkering with it and found I have spark at #3 cylinder. From there I tested the other coils by switching terminals to that good one. All other cylinder had good spark with using #3 terminal on power pack.
Having done that, I'm now thinking may be a bad sensor under flywheel. Looks like there are two paired sensors under there, Which would make me think I should at least get a spark on 2 cylinders since 1 sensor operates 2 coils. In which case, I am in the process of checking continuity in the wires leading from the sensors to make sure there are no short in those wires. "are we having fun yet?"
As far as ignition, the off position should be closed to ground to cut off motor, in on/start position should be open to allow no ground, so when I am cranking should I be getting a light pulse with my tester at the powerpak terminal 1?

Too much to think about right now, right.....
Thanks so much for all your input and help.

 

[F_R]

Re: Kill Switch, no spark 73' 85hp Johnson

Each sensor triggers two SCRs in the power pack. In other words, a negative sensor pulse triggers one cylinder and a positive pulse triggers another cylinder. Negative and positive pulses are determined by the north/south polarity of the magnets as they pass by. At least that's the way I understand it.

 

[captain94]

Re: Kill Switch, no spark 73' 85hp Johnson

New topic started for captain94. See link below.

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1216432

 

[DJ]

Re: Kill Switch, no spark 73' 85hp Johnson

captain94,

I have started another thread for you.

It is considered rude to "hijack" anothers thread.

The link to your thread is below.

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1216432;gpid=1216432#gpid1216432

 

[rbbrox]

Re: Kill Switch, no spark 73' 85hp Johnson

Each sensor triggers two SCRs in the power pack. In other words, a negative sensor pulse triggers one cylinder and a positive pulse triggers another cylinder. Negative and positive pulses are determined by the north/south polarity of the magnets as they pass by. At least that's the way I understand it.

Yes, that is the way I understand it as well. Still doesn't make sense that only the #3 cylinder has spark...?

 

[rbbrox]

Re: Kill Switch, no spark 73' 85hp Johnson

Would a bad ignition switch take out 3 out of 4 cylinders?

 

[rbbrox]

Re: Kill Switch, no spark 73' 85hp Johnson

I think my next purchase should be a M-80 NEON TESTER so I can really nail this down. Where can I buy one?

 

[Indymike]

Re: Kill Switch, no spark 73' 85hp Johnson

CDI Rapair has a good troubleshooting guide to download .

http://rapair.com/index.php?option=com_content&task=view&id=26&Itemid=34

You can get a 12 amp stator for that motor, and also a voltage regulator. I have put both on my 73 115 and I never have starting issues, and I don't need to charge the battery between outings. ( knock on wood). If your motor has the original stator it probably needs replacing.
If you look close it is probably leaking potting compound.
Btw I use an 85 amp hour 550cca dual purpose battery.

Get a good multimeter and a peak reading adapter for troubleshooting and a Johnson service manual.

Mike