1996 johnson 35hp ignition issue

[Jred1]

Just wondering if any one has any advice my johnson will fire up fine on muffs idle up for about 5-10mins then die as soon as its warmed up its not overheating i have spark when the motor is cold bit as soon as it dies i loose spark in all three cylinders now what are the chances that all three coils are bad simultaneously or should i be looking further up for heat failure stator possibly? the power pack has been replaced about 2 years ago. Any insight on this issue would be greatly appreciated

 

[Mohawkmtrs]

For their troubleshooting guide, go to cdielectronics dot com.

 

[oldboat1]

How do you measure spark, and how do you measure temperature? How about other tests -- Compression tested?

What were the symptoms/tests that led you to replace the power pack?

(Looking for more to the story. What is the model number for that motor?)

 

[Jred1]

I dont have a proper gap tester just did visual to a ground bright blue spark compression is 90psi all 3 cylanders power pack was replaced by my old man said it worked after that im not sure full story then it sat for a couple years. ive rebuilt the fuel pumps, Each time it dies i check the carb bowls full of fuel cleaned carbs previously getting lots of fuel, at first i thought it may have been my temp sensor or thermostat checked both ran without thermostat same results ran without temp sens and used my temp gun on the heads i think it hit around 170f was the hottest it got before dropping when my thermostat opened. Also replaced the spark plugs and wires the model is J35TKLEDC

 

[racerone]

What kind of wires did you install.----Factory plug wires or something else ?

 

[oldboat1]

I would go back to basics. Change out the impeller and make sure cooling system is working correctly (170 is too hot. t.stat is typically 140, and motor will idle somewhere around 120 -140 in a barrel or on muffs. Do not rev the motor unless you are in the lake.) Get an adjustable open air spark tester and measure spark. In addition, hook up a timing light to determine when spark loss occurs -- not to measure timing, just a device to perform cylinder drop test.

Locate the 20amp fuse and replace it with a fresh one. If you have a tach, check it to make sure it's working normally.

90 psi is borderline, but may be your gauge (try another one if possible).

 

[Jred1]

Spark plug wires are johnson/evinrude and they are ss marine grade wires. The water pump was recently replaced and i just had the motor in gear in a tank to get the temps up but i also removed the t stat to test and the temp never passed 100f and same results after about 5-10 mins of run time i will see if i can get my hands on a timing light no open water where im from this time of year so im limited to testing in shop in a barrel i will see what else i can find thanks

 

[oldboat1]

can do a lot with barrel testing, imo, but keep the rpms down. Might test the stat to see if it's opening at 140F (cup of hot water and a pair of kitchen tongs).

 

[Bosunsmate]

Id disconnect the kill wire and try again to try and narrow it down, just choke it or reconnect kill circuit to stop her.
Also ohmn test your parts that a under the flywheel

 

[Jred1]

So i just got around to ohm testing my stator it was just within spec i tested my coils next and my primary was with in spec but when i tested the secondary on all 3 coils i just got a 1 i checked spark still had good spark having not run engine but could all my coils be on the fritz out put is supposed to be around 200-400ohms