Force 125 89. no spark on one cylinder

shakazulu · Nov 17, 2011

On my force 125 89. one cylinder stopped working. There is no spark on 3rd cylinder. I swapped 3rd and 4th coil to see is 3rd coil bad.
When orange wire from rear CDI is connected to 4th coil ( lowest), there is no spark on 4th cylinder. Red wire from CDI to 3rd cylinder - 3rd cylinder works.
When orange wire from rear CDI is connected to 3rd coil , there is no spark on 3rd cylinder. Red wire from CDI to 4th cylinder - 4th cylinder works. So problem is in orange wire from rear CDI.
So result of this is that all coils and plugs are good.
I am suspicious on rear CDI but it seems that only half of it is bad because one cylinder does not have spark and not both. Am I right? Can CDI be faulty only for one cylinder ?
Can there be problem before CDI - wires from stator or trigger ?
I have blue coils and CDIs, prestolite system .

Motor starts good, idles good ( I hear caugh from carb - probably because faulty cylinder ). It runs till 2500rpms and this is max. Boat - bayliner 1902 cuddy can plane but after long time with only one person.

Fuel pump was rebuilt 18 working hours ago . I checked all wires for loose wire, they are all good connected.

I would like to ask good mechanics/electricians to give me advice what to do next, how to be sure that it is CDI ? Which tests sholud I do next?
Thank you everybody for help

pnwboat · Nov 17, 2011

Re: Force 125 89. no spark on one cylinder

Very common problem for one side of the CDI to go bad and only affect spark to one cylinder. First check the trigger wires for #3 cylinder on the 12 position terminal block. There is usually a small piece of black insulation covering the wire where it is crimped and soldered to the spade lug connector that goes under the screw on the terminal block. I've seen several cases where the trigger wire has broken right there inside the black insulation and is not visible, or just a single strand of wire holding to make the connection. If no broken trigger wires, then most likely the CDI is bad.

MM2SS · Nov 17, 2011

Re: Force 125 89. no spark on one cylinder

Make sure to test the stator, it supplies electricty to both switchboxes. If one side is bad it can make the switchbox appear bad. My '89 125 had weak spark to #3 and no spark to #4. I was certain that it was the forward switchbox but when I switched connections on the boxes it proved to be good. I think the ohms reading on the stator should be 700-900. Mine was only 600 on one side. When I replaced the stator the problem was solved. Outboardignition.com had the best price on the same part number as Iboats. Huge savings. Good luck.

shakazulu · Nov 17, 2011

Re: Force 125 89. no spark on one cylinder

Thank you for answers. I am planing to check cd module output voltage , trigger and stator resistance and voltage with multimeter . And I will check one more time for bad wires below black insulation covering. Then I will consult you again

jerryjerry05 · Nov 18, 2011

Re: Force 125 89. no spark on one cylinder

Start with a compression test.If the comp is good then proced with the tests.
Try switching packs around.Take pics and write down the wiring diagram.That way you can make sure it's back together right.
Sending you a pm.J

shakazulu · Nov 18, 2011

Re: Force 125 89. no spark on one cylinder

I found one more interesting thing. It is about kill switch wire. It seems that white kill switch wire from rear cd pack does not work. I disconnected both white wires on terminal on left side of motor and then I started motor with key . Then turned key off and motor kept runing, then I touched terminal screw with kill switch wire from rear pack and motor did not turn off. Motor turned off when I touched screw on terminal with white wire from front cd pack . So motor does not react to kill switch wire from rear pack ( the one that is suspicious ) . Is this enough that I can make conclusion that rear cd pack is bad?

3rd cylinder does not have spark and kill switch wire from rear cd pack does not work.

If it is not enough to have conclusion I will have to switch cd packs and test. In this procedure what is most important to take care?
My plan is to leave wires from trigger on their places on terminal and change places of wires from cd packs but again with same colors.
I asume that I don't need to touch anything with cables from cd packs to coils.

shakazulu · Nov 18, 2011

Re: Force 125 89. no spark on one cylinder

And I asume that after cd packs swaped I need to switch on terminal blue and yellow wires from stator

Jiggz · Nov 18, 2011

Re: Force 125 89. no spark on one cylinder

No you don't need to switch the stator or trigger wires around. Just the CD packs. It's like replacing CD packs, remove the old one and put in the new one. No trigger or stator wires to switch around. Except in your case you remove the suspected bad cd pack and then replaced it with a known working cd pack. The suspected bad cd now goes into the known working cd position. In short just a straight swap on cd's and nothing else.

shakazulu · Nov 19, 2011

Re: Force 125 89. no spark on one cylinder

Today I switched cd pack wires. I tried to start the motor but didn't start, starter was cranking but motor didn't start . I was alone on the boat so I couldn't check for spark on cylinders so I will do it next time when I have assistant on boat.
Before I wrote about bad white wire ( kill switch wire from rear cd pack ) that does not react and does not kill motor, is this sympthom of bad cd pack ?

How many Ampers does the starter spend? My battery 75 Ah fell down from 12,3 Volts to 11,5 V after lot of cranking and I think I will need to charge it on land.

shakazulu · Nov 19, 2011

Re: Force 125 89. no spark on one cylinder

Now when I switched cd packs, is timing the same or it needs to be adjusted again?

jerryjerry05 · Nov 19, 2011

Re: Force 125 89. no spark on one cylinder

Timing is ok unless you adjust at the towershaft.J

shakazulu · Nov 22, 2011

Re: Force 125 89. no spark on one cylinder

I tested cdi packs after swap and they are both good. The problem is still on 3rd cylinder, no spark. Is it stator or trigger?

pnwboat · Nov 22, 2011

Re: Force 125 89. no spark on one cylinder

Check the resistance of the stator between the Blue and Yellow wires that go to the 12 position terminal strip. They should read be between 680 - 850 ohms. Make sure you disconnect at least one of the wires from the terminal strip so that no other circuitry affects the readings. There are two pairs of Blue and Yellow leads that connect to the 12 position terminal strip. One pair usually marked 3 & 4 supply voltage to the CDI that fires #3 & #4 coils. The other pair marked 1 & 2 supply voltage to the CDI that fires #1 & #2 coils.

To check the trigger, measure the resistance between the 4 pairs of wires. They should read between 48 - 52 ohms.

shakazulu · Nov 25, 2011

Re: Force 125 89. no spark on one cylinder

I don't know why but my multimeter did not show any resistance on stator, only number 1 all the time. Maybe problem is with my multimeter. Do I need to unplug all wires from stator when doing resistance test ( those to the rectifier also ) ?
How can I make more tests of stator without multimeter? Can I swap wires from stator that go to rear cdi, blue and yellow? Do theese two wires give the same electricity? One wire should give power to 3rd and one for 4th cylinder.

And which wires can be swapped from trigger to test trigger?

CharlieB · Nov 25, 2011

Re: Force 125 89. no spark on one cylinder

shakazulu said:
I tested cdi packs after swap and they are both good. The problem is still on 3rd cylinder, no spark. Is it stator or trigger?

Are you saying that you physically removed both paks, switched their positions and tested spark again and the same #3 failed to spark?

Stator charges a pak, the pak determines which cyl to fire, a bad stator will not fire just one cyl on a pak.

It is beginning to look like a bad trigger.

Reread post #2 as a bad wire on a trigger will cause your problem.

CDIElectronics has an excellent Ignition Troubleshooting Guide that spells out in detail how to test your system to prove which part is at fault. Free download on their Support pages.

There is NO RETURN on electrical parts so you want to be sure before you start spending money on parts.

shakazulu · Dec 6, 2011

Re: Force 125 89. no spark on one cylinder

Sorry for my late reply, I didn't go on boat for a while. Yes, I physically swapped power pack wires and it prooved to be that both packs have spark but the problem is still on same cylinder. And one power pack has bad white wire ( kill switch ) because it won't kill motor when key off .
So you say that problem is not on stator and that it could be bad trigger ? How often trigger is the problem?
I checked all wires and they are all well connected.

pnwboat · Dec 7, 2011

Re: Force 125 89. no spark on one cylinder

The power pack that will not kill the spark when the white wire from it is grounded (ignition off) is bad.

shakazulu · Dec 8, 2011

Re: Force 125 89. no spark on one cylinder

pnwboat said:
The power pack that will not kill the spark when the white wire from it is grounded (ignition off) is bad.

Yes, it is bad on kill switch but it works good for spark. I will have to retest it again to be sure

jason32038 · Dec 8, 2011

Re: Force 125 89. no spark on one cylinder

About the rear kill switch wire...clip the terminal connector off and strip the sheathing off and retry your test with bare wire. If it kills it you will know it was a bad connection with the wire and connector OR a bad connection on the strip. If you have all terminal connections i'd suggest you replace them all first and try again. They like to corrode and rust and cause problems especially with salt water use. If your cd packs have been spliced with crimp connectors replace them. The connectors are pretty cheap and it's a good starting point. Just because a wire connection seems secure doesnt mean it's getting a good connection. Good luck!

shakazulu · Jun 27, 2012

Re: Force 125 89. no spark on one cylinder

I am writing again after 6 months because I still did not solve the problem with my force 125. There is no spark on one cylinder. I replaced power module and it was good module. So that was not the problem. Now I am planing to replace trigger or stator. I have one old motor for parts but it is 150hp Force 5 cylinder. Does it have the same stator and trigger like my Force 125 ? Thanks

Force 125 89. no spark on one cylinder

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