Force 120 no spark

[wolfie-uk]

hi all,

one of the refurb engines ( 1993 ) has no spark on number 1 and 2 cylinder, is it possible to have two points on the trigger go down or is it more likely to be the front cdi unit? if so what is the best way to prove the trigger is ok and that the cdi is the culprit ?

I have a 125 hp (1989) electric set complete which is good, but the wiring colour scheme is different, now it seems straight forward enough in swopping the entire system over, but will it work ok ?

regards

 

[pnwboat]

Re: Force 120 no spark

Sounds like form your comments that you have a Prestolite ignition system on the 1993 motor. If so, then yes you can swap.

Before you start swapping the ignition components, you need to check the stator. Disconnect the Blue and Yellow stator wires that go to the front CD Module. Measure the resistance between them. It should be 680-850 OHMs. You can compare the readings to the Blue and Yellow wires that go to the rear CD Module. They should be pretty close to the same reading. If they don't read according to specs, then the stator winding that feeds the front CD Module is bad and the stator needs to be replaced.

You can check the resistance of the trigger windings. Disconnect before checking. They should be 48-52 OHMs.

If the stator and trigger checks out OK, then try swapping the front CD module or switching ignition components from your spare set. Caution, there a lot of wires. Take pictures and or take careful notes as to the wiring. Many problems have been created when swapping ignition components due to incorrect wiring.

 

[jerryjerry05]

Re: Force 120 no spark

93 came with 2 systems, Prestolite and the Mercury.
You want to put the Prestolite on the Mercury system.
Not absolutly positive but the timer base might need to be changed.
The flywheel probably too.
Try to troubleshoot the system first?
Might be a loose wire? maybe a bad connection?
Try switching the packs around?
The trigger connectors are very thin and under the shrink wrap break and loose contact.
Try replacing the connectors, on the stator and packs too.

 

[wolfie-uk]

Re: Force 120 no spark

hi both, thanks for the info so far, will bring my multi home tommorow and test the wiring as per instructions above, i am lucky in that both engines still have the original wiring diagrams and colour schemes on them, and also a bonus they are both the blue prestolite systems, will keep the thread updated as i go along, sure hope its just a loose / bad connection.