Pulling Spark Plug Boot Makes No Difference

[Pjrogu]

The 88' Force 125 on my Capri idles great and starts right up, but has no power at WOT. I am getting a tach soon, but can tell it does not sound like it reaches peak rpm and is limited to about 7mph. The Comp is ~130 across the board. I went and pulled the boots off the plugs while it was running and found that cylinders 1 and 3 made no difference when pulled off, but 2 and 4 would instantly kill the motor. Also, it would idle with both 1 and 3 off at the same time! This leads me to believe I have been running on 2 cylinders the whole time.

I replaced the CDI and coils and now it only runs when plug 4 boot is removed. I see spark on all 4 plugs when grounded to the block. Haven't tested it on the water to see if the power is up, but is it strange that there is not change from shutting down 2 cylinders? Should I investigate stator or trigger as possible avenues of problems?

 

[Redbarron%%]

Check that the ignition is firing the plugs in the correct order. If the plugs are swapped they will fire at BDC and make no difference in power. If out of order then they will kick back.

 

[The Force power]

The 88' Force 125 on my Capri idles great and starts right up, but has no power at WOT. I am getting a tach soon, but can tell it does not sound like it reaches peak rpm and is limited to about 7mph. The Comp is ~130 across the board. I went and pulled the boots off the plugs while it was running and found that cylinders 1 and 3 made no difference when pulled off, but 2 and 4 would instantly kill the motor. Also, it would idle with both 1 and 3 off at the same time! This leads me to believe I have been running on 2 cylinders the whole time.

I replaced the CDI and coils and now it only runs when plug 4 boot is removed. I see spark on all 4 plugs when grounded to the block. Haven't tested it on the water to see if the power is up, but is it strange that there is not change from shutting down 2 cylinders? Should I investigate stator or trigger as possible avenues of problems?

Welcome

Here a link to diagnose the ignition system;

https://www.outboardignition.com/page6.asp

 

[The Force power]

AND....welcome to IBoats :welcome:

 

[jerryjerry05]

You check the gas for water?
Post a pic of the plugs? Shutterfly or any photo
sharing site will help.What plugs?

More history? did it set, new to you? any thing you can think?

 

[Pjrogu]

The motor is new to me replacing my old force with a cracked block. I changed the coils and CDI packs with my original ones and now see a brighter spark, but can still pull cyl 4 with no effect on idle. One thing I noticed, the trigger wires coming from under the flywheel only has 5 wires, 4 colored going to the CDIs, and 1 black. My old motor had 8 wires with 2 pairs for each CDI. I don't understand how this new trigger works with 2 wires missing from each CDI. Anyone see this style trigger before?

 

[Pjrogu]

You check the gas for water?
Post a pic of the plugs? Shutterfly or any photo
sharing site will help.What plugs?

More history? did it set, new to you? any thing you can think?

 

[jerryjerry05]

I think I answered your question in another post.
Try to keep the questions for the same motor on
just one thread. Confusing

 

[Redbarron%%]

If you have 4 wires with the fifth a solid black you might have a CDM engine with the trigger coil for them
(I don't know your engine, but most CDI triggers have a White/Black common trigger wire where the CDM has a solid black, but --------- I am not that familiar with y our engines, just the 90 hp Sport jet and it has the White/black for the CDI (that goes to the switch box) and the black for the CDM that directly ties to ground.
If you have the flywheel with the CDM trigger coil I would think that you are lucky as you can change out the CDI boxes and coils to the individual CDM modules and gain some reliability.
Look up the troubleshooting data on the 4 cylinder CDM trigger coil to see if it matches.
The CDI trigger (working from memory) measures 100-1200 ohms colored wire to white/black and the CDM coil shows no connection from the colored wires to the black wire since the bias circuit is built in the trigger and is not in the box like the CDI.
If you have the flywheel with an internal thread at the hub for the puller you almost certainly have a CDM motor.

 

[Redbarron%%]

Here is a link to the trigger coil information.

https://www.go2marine.com/Product-Guides/MFR/CDI/mercury-trigger-magnets.pdf

 

[jerryjerry05]

I opened this link, pretty cool once it translates from
Russian to English.
http://files.motorka.org

 

[Pjrogu]

jerry Thanks for the response, I thought I had to make a new post since it was a separate question about the specific trigger rather than my no spark issue.

After checking the CDI website, it is just the replacement with fewer wires.

The latest with the motor is it can idle on any 2 cylinders with no difference in sound difference once you pull the boots. Example: 1&4 2&3 3&4. So it seems that all the cylinders are firing and the motor has no issue running on 2. Very weird...