spark problems

[jvon]

1990 Johnson 200hp
When I check my spark with a gap tester I only have spark on the middle spark plug on the port bank. I have tried taking the the tan wire off to bypass the heat sensor, no help. I put all the wires back on and the motor started. I pulled one wire off and put the spark gop tester on, and started the motor and had spark where I didn't have spark before. By the way, don't do that it will back fire. I am lost, thinking it is the power pack.

 

[Joe Reeves]

Re: spark problems

Proper method to check spark.

Remove spark plugs so that the engine will crank at the highest rpm possible. The engine must crank over at least 300 rpm in order to engage the ignition system.

Rig a spark tester whereas a gap of 7/16" can be set. The spark should jump this gap with a strong blue lightning like flame.... a real SNAP!

(Spark Tester - Home Made)
(J. Reeves)

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:


..........X1..........X2

.................X..(grd)

..........X3..........X4

 

[jvon]

Re: spark problems

thanks will try now

 

[jvon]

Re: spark problems

I took the plugs out and it spinns over very fast. Still the same thing, only spark on the middle, left bank

 

[Joe Reeves]

Re: spark problems

Disconnect large RED electrical plug at engine. Crank engine by using a jumper wire between the large battery terminal of the starter solenoid to the small 3/8" nut terminal of the solenoid that engages the solenoid (not the 3/8" ground nut).

If you now have spark, suspect the ignition switch to have a slight short. To check the switch, reconnect that RED plug, then remove the black/yellow wire from the back of the switch. If you have spark with it disconnected but do not when it is connected, replace the ignition switch.

If no change with the RED plug disconnected, look closely at the stator under the flywheel, especially the large BLACK coils to the rear of the stator (beginning of ignition and charging system). If either of them are cracked and/or dripping a sticky looking substance down upon the timer base and powerhead area, replace the stator.

 

[jvon]

Re: spark problems

I disconnected the main plug, checked the spark and no change, still just the middle one on the port bank. Took the flywheel off and the stater looks great. I thnk the guy I bought this from say it was replaced about 5-6 years ago.

 

[jvon]

Re: spark problems

help

 

[Joe Reeves]

Re: spark problems

The spark on the middle cylinder..... Does it jump a 7/16" gap with a strong blue lightning like spark? If not, describe the spark. Note..... do not check the spark simply by using a spark plug as it is a waste of time and will give a wrong reading.

Assuming that you've visually inspected the stator thoroughly top to bottom, check all of the connectors...... the pins and sockets that are in the rubber plug connectors. They've been known to back out somewhat at times resulting in a poor or non existent connction with each other and/or having the wire break at the end of the pin/socket that is within those rubber plugs which gives the illusion that the pin/socket is connected to the wire when it is not.

This would of course result in weak, erratic, or no ignition (spark).

If all is as it should be, I suggest that you check the ohm reading on the timing base sensors as listed in your service manual (I don't have those specifications at my fingertips right now).

 

[jvon]

Re: spark problems

Yes it had a very good spark across the 7/16 gap. I am checking the timing pick up, under the power pack there are a couple brown wires coming from the stator and running to the port side of the pack. One of these wires looks like it was pinched pretty bad, can I cut and reconnect this wire or replace the pwer pack.

 

[Joe Reeves]

Re: spark problems

Considering the price of a powerpack, I'd repair the wiring.

 

[jvon]

Re: spark problems

bump

 

[Joe Reeves]

Re: spark problems

Those brown brown/yellow wires are the voltage supply leads from the stator to the powerpack. If damaged, a voltage drop will exist to the powerpack resulting in weak, erratic, or no ignition.

 

[jvon]

Re: spark problems

fixed the wire and still no change. Will try to run the motor in the lake soon.

 

[Lion hunter]

Re: spark problems

Lake water won't make it run any better. I would get it fixed before turning loose on open water.