4hp Johnson CDI Complicated Question

[sailortoo]

HELP -One heart beat from giving up.
PROBLEM: Timer base supplies 4 volt AC to power pack. Two wires from sensor both have the 4 volt as measured by DVA meter. One wire into the power pack for cylinder 1 has 4 volts input-power pack output is 120 Volt--correct. One wire into the power pack for cylinder 2 has 4 volts input-power pack output is 000 Volt.

I have tried three (3) different power packs and get the same result. It is almost inconceivable that all three power packs could be faulty. SOOOO, does anyone have a suggestion that I might try. I have a DVA meter and have checked all input & output voltage as above. Also have new coil, but since there is no powerpack output that's a moot point.

Thanx for reading!


sailortoo

 

[Joe Reeves]

Re: 4hp Johnson CDI Complicated Question

What's the model number of that engine?

 

[sailortoo]

Re: 4hp Johnson CDI Complicated Question

Joe:

Model J4RLCEC - which is 1989 Johnson Sailmaster - Mfg Belgium
2 cyl long shaft - pull start.

Thanx!

 

[Joe Reeves]

Re: 4hp Johnson CDI Complicated Question

The wires from the sensor (which I believe is incorporated within the armature plate/timer base)..... reverse them.

If the non firing coil now fires (situation reversed), suspect the sensor.

 

[sailortoo]

Re: 4hp Johnson CDI Complicated Question

Joe:

When I used DVA to check for 4VAC, I reversed the DVA leads and did get the correct 4VAC on the sensor wires @ the DVA meter either way. I will try your suggestion.

Thanx for the info. I will advise results.

Sailortoo

 

[sailortoo]

Re: 4hp Johnson CDI Complicated Question

Joe:

I reversed sensor leads and still get the same result. Let me try one more time: There are 5 connections on the power pack, to simplify:

Power pack 1 in - black lead from sensor produces 4VAC - ok
Power pack 2 in - white lead from sensor produces 4VAC - ok
Power pack 3 out - brown lead to coil primary 120V - ok
Power pack 4 out - brown/green strip to coil primary 000V - problem
Power pack 5 out - black wire to kill switch (disconnected for test) -
checks ok

I have tried three power packs (one brand new) and get the same result--no voltage @ connection 4 from the power pack. Even when I switch sensor leads @ 1 & 2 I still get no voltage from the power pack to coil primary. I have run new wire on all connections. I have used the DVA connecting it directly to the connection 4 on power pack----000V.

Also, there is no spark from the coil secondary even though the voltage on the primary is present - 120V --connection 3 above. Should't I get spark on the half of the coil that is receiving the 120V from the primary?? Also, why would all three power packs exibit the same fault?

Thanx again
sailortoo
This is gettin' long winded so I will close and thank you for your reply. I have taken this motor to three Johnson mechanics who don't have an answer either. End note: the timer base and the power pack are no longer available for this motor. I got the last new power pack from the manufacturer - $150 and it dosen't work either.

 

[Joe Reeves]

Re: 4hp Johnson CDI Complicated Question

You state above: "Also, there is no spark from the coil secondary even though the voltage on the primary is present - 120V --connection 3 above. Should't I get spark on the half of the coil that is receiving the 120V from the primary?? Also, why would all three power packs exibit the same fault?"

I take this to mean that you have switched the lead of the powerpack from the firing coil to the non firing coil..... and the non firing coil still does not fire. That would indicate that the coil is faulty.... BUT.... I believe you said that the coil is new also. Frankly, at the moment, I am at a loss to comprehend this. Anyone else run into this type problem?

 

[HighTrim]

Re: 4hp Johnson CDI Complicated Question

I believe that motor has a single ignition coil, with 2 leads, correct? That is what you replaced, along with the pp?

Could the sensor coil not be going bad due to less resistance? Have you actually tested it? I did not see you mention. I realize that you are getting the necessary 4VAC into the PP, but could some of the turns of the copper wire not be shorted out, and when the coil heats up or cools down, the expansion or contraction causes the coil to short? Many times a DVA test can miss this problem. Try testing the resistance between the leads, and for a short to ground.

Just a thought, as it is a strange problem indeed.

 

[sailortoo]

Re: 4hp Johnson CDI Complicated Question

Joe & Chris:

Thanx for the feedback. Ok --let me try this:

A:
I have 4VAC from one wire on the sensor going into the power pack. The power pack has a connection that goes to one of the primarys on the coil. The power pack does not generate the required 120V to send to the coil.

B:
I have 4VAC from other wire on the sensor going into the power pack. The power pack has a connection that goes to other primary on the coil. The power pack generates required 120V into the coil. However there is no spark out of the coil.

The coil has two primary terminals input and two secondary terminals output to the spark plugs. The coil is new and I have checked it with an Ohm Meter and have the suggested resistance.

The trouble points to the power pack and I have tried three different ones. But even when I switch the sensor leads into the power pack the same power pack output connection fails on all three power packs regardless of which sensore lead is connected.

It seems like I should get spark on the secondary coil terminal that is receiving the 120V from the power pack.

I am not aware of any way to check the power pack??

Looks like I might be done with this motor. Send me an address and mabe I can ship the motor along with a case of beer to give you something to do on a Saturday afternoon.

 

[HighTrim]

Re: 4hp Johnson CDI Complicated Question

I think that you may have misunderstood my post, you need to test the sensor coil, not the power pack. Let us know if you need help with this, as there are 3 parts to this, the ohmmeter test, ground test and output test.

I would first though ensure that all the pins in the connectors are in good shape and not bent at all, take them apart and inspect closely. Inspect the orange/blue wire and its connections on the lead that is not providing the necessary voltage. Checking the continuity of the wires may help pinpoint a trouble spot.

I wouldnt give up yet, you can nail this problem.

 

[Xcusme]

Re: 4hp Johnson CDI Complicated Question

Hmmm, Sailortoo, just so I get this right...are you getting spark to either plug or no spark at all to the plugs??

FYI: If I understand your setup, you should get 100-200VDC to each of the brown AND brown/green wires constantly from the power pack (as long as the flywheel is spinning and the under flywheel coil is good). I think you have things a bit confused. These 2 wires don't supply voltage TO the coils, they are on the back side (return side) of the primary windings of the coil pack for their respective cylinders.
The 100-200VDC leaves the powerpack through a short wire that gets mounted to the powerhead (underneath powerpack mounting bolt, touching powerhead). The whole powerhead is at 100-200VDC potential.

The coil pack gets it's 100-200 volts from the powerhead connection itself. Voltage enters the coil pack in it's mounting base (hence the metal tabs on the mounting holes or flying lead). The voltage goes through the primary winding of each coil and leaves the coil pack on the brown and brown/green wires BACK to the power pack. The power pack grounds each of these wires in turn, to the negative side of the charge capacitor, through SCR's which are triggered from the timer base. The sudden current flow in the primary winding induces the secondary coil winding, upping the primary voltage to produce the voltage necessary to fire the plug.
Since your not getting voltage through the primary side of the coil, you may have either an open primary coil wire or that side of the coil pack is not connected to the powerhead.
Check the timer base coil for any shorts to ground (powerhead) , opens and resistance. Be sure timer base resistance is within factory specs.

Disclaimer: If yours is not a CD ignition type described, disregard some or all of the above. I'm sure those more familiar with your particular ignition system will jump in to set things right and corrections are welcome. Sadly, I don't have a wiring print for your motor.

 

[sailortoo]

Re: 4hp Johnson CDI Complicated Question

Chris:

I did three tests on the sensor:
Test 1 - Ohm Meter red lead to sensor black wire & black lead to ground-No
reading. Red lead to sensor white wire & black lead to ground-No
reading either wire.
Test 2 - Ohm Meter Red lead to sensor white wire & black lead to sensor
black wire - 100 ohms. Reverse same.
Test 3 - DVA Meter red lead to white sensor wire & black lead to black sensor
wire - 4VAC. Reverse leads - 4VAC.


Xcusme:

There is nothing under the flywheel on this motor. I removed the flywheel when I first started troubleshootin' this thing to check. There is only the timer base which is a circular bracked attached to the throttle with the sensor on the outside of the flywheel. When the throttle is advanced or retarded the sensor rotates around the flywheel therefore affecting the spark advancement as necessary.

The sensor has one black and one white wire which go directly to the PP each supplying 4VAC. The brown wire from the PP goes directly to one of the coil primaries and is supplying 120V. The brown/green wire from the PP goes directly to the other primary on the coil and has 00V. When I switch the sensor leads (black & white) at the PP, I get the same result - 120V on the brown wire & 00V on the brown/green wire. Also, I get no spark on the secondary on the coil which is receiving the 120V via the brown wire from the PP. I have replaced the wires and connectors from the PP to the coil.

I can take some pictures and attach which may show what I am having trouble conveying.

I really appreciate you guys showing an interest in my dilemma. Let me know on the pictures and I will send.

 

[Xcusme]

Re: 4hp Johnson CDI Complicated Question

OK, thanks for the update. I looked up your motor and sadly the pics of the layout are hard to see, very dark. From what I gather, as you said, the trigger coil is on the outside of the flywheel, which is fine. The power pack has to mounted in such a way as to be close enough to the flywheel so the magnets can charge a coil inside the pack to provide voltage to the coil pack, again that's fine. The trigger coil seems to be working just fine. I don't know what the normal coil resistance should be for that coil, a service manual would have that figure. Since it's a coil, I would expect it to have an A/C voltage. The placement of Black and White wires is important too. If reversed going into the powerpack , the wrong cylinder will fire (not the one at TDC). I'm sure the wire connector is keyed for that reason.
The thing that troubles me is, you're getting 120V to only one side of the coil pack. Lift the coil pack and inspect how it's mounted to the powerhead. Not physically, but electrically. Is there only one metal contact to the powerhead or is each half of the coil pack 'grounded?

You have a PM....

 

[HighTrim]

Re: 4hp Johnson CDI Complicated Question

The sensor coil resistance is 85 to 115 ohms, so you are within spec at 100 ohms.

No continuity should be detected between the sensor coil wires and ground, again, you are good there.

Sensor coil output should be 4 volts or more, good there.

Also try using the DVA meter for a ground test. Connect the black meter lead to a good engine ground, and use the red lead to touch terminal C (blue/white wire??) and note the meter. Move the red lead from terminal C to D (white wire??), crank engine and note meter. Any voltage output at either location indicates that the sensor coil or its wires are shorted to ground.

Did you check all the pins in the connectors for being bent or damaged? From PP to coil?

 

[CharlieB]

Re: 4hp Johnson CDI Complicated Question

Have you checked the magnets in the flywheel, to be sure that all are roughly the same strength using a screwdriver tip and feeling the magnetic 'pull', and that none are loose?

 

[sailortoo]

Re: 4hp Johnson CDI Complicated Question

Tried to respond on 15th but forum was down.

CharlesB: Yes I checked flywheel magnets. They had a thin black power coat and I used a little emery cloth to "buff" em' up a little. None are loose and seem to have the same magnetic "pull".

Thanx

Chris: Yes I checked the sensor wire to ground with meter while cranking engine. No readings on either wire. PP is new and there are no loose pins and I replaced the wire and connectors.

Thanx

Xcuseme: The PP came with a plastic spacer to set the gap to the flywheel which I use on installation. I have tried reversing the sensor wires at the PP-no change in fault--only 120V on one PP output terminal (pin) and no spark on coil secondary. The coil has two mounting holes with metal tabs on the bottom. The coil is mounted vertically 'bout two inches below the PP. I used the meter between the mounting bolts and have continuity. Still there is no spark on the seconday from the primary that receives the 120V from the PP. Should three be a secondary spark? I used a spark tester.

REMEMBER: TIME SPENT BOATING IS NOT SUBTRACTED FROM YOUR LIFE!!

Thanx

sailortoo

 

[clanton]

Re: 4hp Johnson CDI Complicated Question

I may have a manual for this engine, if so will report back tomorrow.

 

[clanton]

Re: 4hp Johnson CDI Complicated Question

The one sensor fires the 2 cylinders by firing once on the south end of the magnet and once on the north end of the magnet. So your test indicates the sensor is good. Your test indicates bad powerpack, weak flywheel magnet. Have you checked the ignition coil grounds, the metal tabs must be grounded to the block. Where did new pack come from??

 

[clanton]

Re: 4hp Johnson CDI Complicated Question

What is pp and sensor airgap?

 

[sailortoo]

Re: 4hp Johnson CDI Complicated Question

clanton:

Excusme suggested I check the coil for proper grounding, which I have not done yet due to the extreme cold in Florida (39 degrees), however, I believe that the coil is properly grounded. It has two mounting holes with metal tabs and is secured directly to the powerhead w two bolts. The pp, last one in the world, is the exact replacement from the original manufacturer. Funny thing, though, it exhibits the same fault as the old pp and another used pp I tried.

The "pp" is "power pack" and the "sensor air gap" would be the distance from the sensor to the flywheel. The sensor revolves around the flywheel when the throttle is advanced or retarded thus affecting the spark in the same manner. The gap is unajustable.

Thanx for the interest.

Time spent fishin' is not subtracted from your life!

sailortoo