1996 Johnson 15hp (manual start) 4-stroke intermittent starting

[horsetrader]

my Johnson 15hp 4-stroke starts sometimes after about 20-30 pulls but more often than not, it will not start at all. The plugs are new and properly gapped, the carb is newly rebuilt and the fuel is fresh. The few times that it did start, it seemed to run pretty well.

I recently aquired this motor after it had been stored for an unknown time (years?). I have the Seloc manual and have performed the following tests (results included).

Spark test: results = no spark or intermittent at best.

Stop switch test: results = functions properly. Resistance is very high and goes to zero when stop button is pushed.

Charge Coil Test: cranking output = very little, if any voltage produced (normal ~ 300 volts)

Charge coil resistance across the two brown wires = 12,500 ohms (normal ~ 1010-1230).

Power Coil Test: cranking output = very little, if any voltage produced.

Power Coil resistance across the two orange wires = 82 ohms (normal ~ 76-92 ohms).

Power pack/ Ignition module: I was not able to test this, as I do not have the proper load adapter tool.

Ignition Coil Test: resistance across the two plug towers = 2400 ohms (normal ~ 2000-2600).

Questions: Does this sound like failure or intermittent failure of the stator/ charge coil, and is this a common failure?

If not the stator/ charge coil, could it be the ignition module and how do you tell?

Could it be anything else? All wiring and connections are in very good to excellent condition. Thank you very much in advance for providing any help and or insight,

Ron

[boats.net]

Charge coil voltage too low, those tests indicate bad charge coil.

[arhodes_84]

does it have a fuel tank on the motor or seperate from the motor?

[horsetrader]

The fuel tank is separate from the motor and is the original 6 gallon tank that came with the motor. The tank was cleaned very well and new fuel added. I replaced all the fuel lines from the tank to the motor and the supply lines to the carb,then added an in-line fuel filter. I should add that I tried using starting fluid to see if that might get it to start but that did not work.

After eliminating fuel supply problems, I began testing the electrical system. Since it seems to be a problem with the charge coil, I have ordered the replacement from boats.net that should arrive next week. Hopefully, the problem will be solved. I will report back. Thanks,

Ron

[horsetrader]

Well my new charge coil/ stator arrived yesterday, and today I installed it with very high expectations.

Result: Engine still will not start, which is frustrating since I spent the money on what I thought was the problem based on my test results.

I performed all the previous tests again, with normal results on the tests that involved the charge coil. Spark test is still negative indicating that the problem may be the power pack/ ignition module or the ignition coil. However, the resistance across the two coil towers is normal so this leaves the power pack/ module as the suspected problem. The ignition module is fairly expensive so I'll have to wait a while before I can afford a new one.

Any other suggestion of what it might be would be appreciated. I guess these things happen but it seems unlikely that an ignition module would fail. Although maybe that is the result of long-term storage and lack of use. I'm just wondering if it might be something really simple that I've overlooked but it seems that I've tested and looked at everything. Thanks very much in advance,

Ron

[boats.net]

Powerpacks are a very commen problem with Evenrude/Johnson and cannot be tested.

[horsetrader]

Being that the stator/ charge coil was not the problem, I went ahead and purchased the powerpack ignition module. It arived and I installed it yesterday.

Success!

Then engine fired right up just like it is supposed to. However, I noticed that there is now no cooling water coming out of the tell tale. The few times that I had the engine running previously, the cooling stream coming from the engine was strong as a result of a new impeller being installed recently. Additionally, I did do this testing in a test tank (i.e., not attached to the hose w/ muffs).

I have checked the thermostat in a pan of hot water and it opens and closes properly but I do have to re-check the opening temperature.

I also started the engine just briefly without the thermostat installed just to see if there was water flow and still no tell tale.

I have also checked the cooling hoses for obstructions and they appear to be clear.

Any help in diagnosing/ troubleshooting the new problem would be appreciated. I'm just trying to think if I'm missing something simple.

Thanks in advance, Ron

[boats.net]

Check the wiring between cahrge coil and power pack if ok and charge coil peak voltage is good then power pack would be suspect.

[horsetrader]

The charge coil and the power pack/ ingnition module are both brand new. Installing these new components solved the original starting problem. The engine now starts right up without a problem. Previously, the few times that the engine started up, the cooling system was working fine. Now, after fixing the electrical system, the cooling system problem showed up.

The new problem (see above) is that cooling water is no longer coming out the tell tale as it did before. How would the electrical system be related to the cooling system?

[boats.net]

Sounds like a water pump impeller. When you tried with the thermostat removed, did you also try with the thermostat cover removed to see if water was flowing to thermostat? Blow compressed air through the tell tale, sometimes critters make nest in the hose.