Johnson 60HP 1992, ignition problems?

[bjornbostrom]

Hello,

I have a Johnson 60hp 1992 (3-cylinder 2-stroke) that has started to fuss a little. It is easy to start and runnit at idle, but when put in gear the motor stops after a few seconds. If I do this a couple of 5-6 times, I eventually get it to run properly. (idle good / does not die when in gear etc). This seems to happen only when the boat is not used for a couple of days. If I, for example, makes another trip the next day the problem does not appear.

Yesterday I started to troubleshoot a bit:

* Comp Test shows OK values.

* I have measured the resistance on all three ignition coils, both at primary and secondary side, and as far as I can see, are all values ​​are within the specification

* I have connected a strobe on the spark plug wires, and here I can see that cylinder 1 and 3 works fine, but the 2nd (middle) have uneven pulses (look likes missing pulses irregularly). This occurs when I have problems getting in gear, once it runs properly it will produce nice pulses to all three cylinders.

The question is what the cause may be? Reading earlier forum posts leads me to the conclusion that it might be the powerpack that needs a replacement?

What do you guys think? Should I go for a new powerpack, or can it be something else?

// bj?rn

 

[WernerF]

Re: Johnson 60HP 1992, ignition problems?

Spark plug, wire, ignition coil, power pack, timer base...
An ignition coil might have the proper resistance and yet has a tiny crack showing up at high voltage only. Even a spark plug can show such an odd behavior.
The quickest and cheapest you can do is swap plugs, wires and coils #1 and #2 and see what happens to your timing light test. The next thing i would suscpect is indeed the powerpack.

 

[WernerF]

Re: Johnson 60HP 1992, ignition problems?

deleted

 

[durban]

Re: Johnson 60HP 1992, ignition problems?

what i would is go to the source that gives the power pack the message first , the sensors . now on your motor the censors are sealed in ,some how when the motor idles at the plug were the timer base wires plug into the other plug there are 4 wires 1 earth & the other 3 are the wires for plugs 1 2 3 , check what happens there first , maybe one sensor is playing up , if u can get a 2ndh one from 1974 60 -75 hp it will do the job , just cut the plug of on your power pack end & connect the wires there , its cheaper doing it this way , you can buy a timer base 2ndh 50dlrs

 

[bjornbostrom]

Re: Johnson 60HP 1992, ignition problems?

thanks for your answers. I guess I will try the ign.coil switch first to see if the problem moves to another cyl. And then go for the sensors

Again, thanks,

// bj?rn

 

[bjornbostrom]

Re: Johnson 60HP 1992, ignition problems?

Hi, posting some updates on the issue.

* Changed the cyl1 and cyl2 ignition coils. The problem still occuring on cyl2 which can remove the ignition coils as the trouble source.

* According to the manual a sensor coil resitance test should indicate between 8-14 ohm. I have measured all three between 11.2-11.5. Also checked for some bad connectors/gounds, but everything seems fine. Can any other tests be performed without the need to disassembly flywheel etc for checking the sensor coils?

* Also, I have experienced some odd behaviour when running the boat at high speed. The engine goes fine, but suddenly it just looses power for 0.5 seconds, and then resumes and run fine again. This has only happened 2 times (one time this year) so far.

This leaves me with the feeling that it is the powerpack. Any suggestions or comments before buying a powerpack is appreciated.

br // bj?rn

 

[bjornbostrom]

Re: Johnson 60HP 1992, ignition problems?

Just for the archive if anyone experiencing the same issue:

Bought a new PowerPack and swapped. No problems so far. I get nice pulses on all 3 cylinders.

// bj?rn