Kill Switch, no spark 73' 85hp Johnson

[rbbrox]

Wondering if a 1973 85HP Johnson has a Kill Switch or an emergency stop switch on the outboard. If so where is it located. Trouble shooting a intermitant spark problem.

Once I finally get a spark going, boat has no problems for the rest of the day.
Thanks for your thoughts.

 

[Walker]

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

Not unless its been upgraded by someone

 

[rbbrox]

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

Not unless its been upgraded by someone

 

[rbbrox]

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

Not unless its been upgraded by someone

Sorry 1st time on site...
What would you guess could be causing the problem.
I have, no spark at all when I first try to start, but after messing and jump starting for 30min all of a sudden I get a spark and it starts. For the rest of the day there are no issues. Very strange.
I traced the ignition with a continuity tester and notice I have no signal at the power pack leading to the coils, do have strong signal at power pak ignition switch terminal. Manual say to use a Neon tester to trouble shoot pak. What says you?
Thanks

 

[ezeke]

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

The cold start complaint is common across the V4 series of motors from 1973-1977. It is mostly the result of inadequate battery power to turn the engine at around 300 RPM.

A smaller standard starting battery is generally not powerful enough.

Make sure the battery is fully charged when you make the initial cold start up.

The fact that your motor is running OK once started
would indicate that the problem is not in the ignition system per se.

You may also want to be sure that the chokes are fully, 100% closed while cranking on the cold start.

 

[rbbrox]

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

The cold start complaint is common across the V4 series of motors from 1973-1977. It is mostly the result of inadequate battery power to turn the engine at around 300 RPM.

A smaller standard starting battery is generally not powerful enough.

Make sure the battery is fully charged when you make the initial cold start up.

The fact that your motor is running OK once started
would indicate that the problem is not in the ignition system per se.

You may also want to be sure that the chokes are fully, 100% closed while cranking on the cold start.

That is another question, Choke, how long should I keep the choke on? The reason I ask is, it seems to flood out if I keep choking while attempting to start.
Regarding the battery, I just purchased a new Interstate deep cell from a respected marine store and even with high RPM still no spark. I've checked all external wiring and grounds which looks to be good. I'm now thinking under the flywheel for corrosion.
Thanks for your help.

 

[ezeke]

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

Choke issue is a little complicated. If the power is there to turn the engine fast enough, then I would keep chokes fully closed until it starts - probably 15-20 seconds.

You have to get fuel to the cylinders from the float bowls - the system will have drained completely. The pistons actually have to pull the fuel into the firing chambers.

If that does not work and you continue choking, you will flood it.

If the engine is not turning over fast enough, it won't matter. Try using two batteries in parallel - you will see and feel the difference.

Feel the terminals on the battery cables after cranking. If they are hot, they may have corroded inside of the sheathing and will not carry the batteries capacity.

 

[rbbrox]

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

Very good, I will try using my jumper battery plus the new deep cycle. That would make sense because when I added the jumper battery before, that is when I finally got some spark. 300 RPM seems to be the ticket.

If the two battery theory works, how do you hook up in parallel?
Thanks, I will let you know how it works.

 

[ezeke]

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

Once the engine warms up you don't usually need the extra power. I would put a switch on the positive feed between the two batteries.

My boats are wired so that I can run on number 1 or number 2 or both.

If you choose to do that you need the right kind of switch or you will have to turn off the motor each time you use the switch or risk burning up the rectifier and possbly worse. The right switch will make contact with the second battery before closing off the first one.

Hint: Don't trust anyone on that. Verify that the switch will make, then break, yourself.

http://www.iboats.com/mall/?category_id=216621&cart_id=800107502&session_id=045556472&view_id=49252

 

[tashasdaddy]

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

sounds like bad cables or connections. if you haven't take them apart and clean them. check your cables for cuts and knick, they will corrode from the inside.

 

[Cricket Too]

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.

 

[ezeke]

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

The 6 amp rectifier won't recharge 1 OR 2 big batteries in normal use. It may be able to maintain the charge on 1, though.

 

[DJ]

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

Regarding the battery, I just purchased a new Interstate deep cell from a respected marine store and even with high RPM still no spark.

That is part of the problem. Deep Cycle batt's don't have as much "kick" for starting.

Remove the negative battery cable, from the engine block, and clean it thoroughly. Those engines are notorious for building up hidden corrosion there.

 

[ezeke]

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

Before we get into this too deeply and confuse things, starting batteries are single function.

Marine deep cycle dual purpose batteries can be used for anything but should have a larger base capacity. The benefit of a deep cycle dual purpose battery is that it can survive more discharge-recharge cycles than a starting battery.

My current primary batteries are deep cycle dual purpose. Maxx-29 is 875 MCA and the West Marine Sea Volt is 775 MCA.

I own and maintain a 1973 135HP Evinrude, and a 1976 115 Johnson. Either battery will easily and consistently start the motors. I expect my batteries to serve 5 to 6 years, and they do.

 

[DJ]

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

ezeke,

I'm well aware of dual purpose batteries. I use them myself. Since the battery was described as "deep cell", I'm not sure what we have here. The fact that a jump makes it spin fast enough tells me two things.

1. The battery may not be up to the task.

2. There may be connection issues.

 

[ezeke]

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

I don't want to muddy the water DWJ, I think that the battery is the problem. I have no idea what his capacity is. At 2:51 today I also mentioned the possible cable problem.

Most dealers don't tell buyers that they need to charge the brand new marine battery that they just paid dearly for. I have bought a few and no one has ever told me that.

 

[F_R]

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

While most of them have been replaced by now, the 1973 models had problems with meltdown of the charge coils. The charge coils are directly related to cranking RPM in that if they are weak higher RPM is required to get enough output for the ignition system to produce spark. Look up under the flywheel and see if that's the case. The original coils were all separate coils on the stator ring. OMC replacements are green and all potted together in epoxy on the stator ring. If there is goo running down off the coils, that is your problem. Might not be the battery at all.

 

[ezeke]

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

Opening: "Once I finally get a spark going, boat has no problems for the rest of the day.
Thanks for your thoughts."

 

[rbbrox]

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

Interesting input and thanks everyone..
The deep cycle batt I was told was for this motor, but it is only 700cca. I will clean all connections and try starting with my jumper batt charger to if I get a spark. Reluctant to go under flywheel at this point.
I asked the store salesman if the batt was charged and ready to go and he said yes, no mention of charging up to make sure...
Thanks

 

[ezeke]

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.