"CDI" or "rectifier" common problem?

[oNemaN]

im pulling my hair out.. i got a 1995 merc force 120 and out of nowhere i lost the spark.. after many runs to get this motor dialed in and running right i lose the spark.. Is the cdi or rectifier something that commonly goes bad.. i replaced the stator and that didnt help. in the prossess i broke a magnet of my flywheel.. is there a way to test that little computer box???

 

[roscoe]

Re: "CDI" or "rectifier" common problem?

Rectifier likely not the culprit.

Could be a bad wire somewhere.
Or the trigger, or the switchbox.

Thinking you are gonna need a Clymer repair manual, and go thru the ignition troubleshooting section step by step.

Test each component, to eliminate the good, find the bad.

 

[MostlyHrmlss]

Re: "CDI" or "rectifier" common problem?

As I understand it, the CDI system in yours is the same as my 1985 85hp, with an extra coil pack. If not, kindy disregard the rest of this blather. The system is self-sustaining, i.e. you don't need +12 from the outside for it to fire. It gets timing and voltage from the "magneto" coils under the flywheel, so if your arm is strong enough, you could rope start it without a battery. Check the wire from the magneto to the CDI boxes, and the grounds on the panel that houses all the ignition stuff. You'll have to consult a diagram (or Frank, the walking diagram for the color.

 

[oNemaN]

Re: "CDI" or "rectifier" common problem?

thank you for the replys.. where can i find this manual to do the proper tests? the starter works fine do i need to rope it? im thinking trigger or recitfier but im at such a loss cause this motor is so clean.. everything looks new. which was nice when i bought it but i found alot of fried wires from the stator to the distrbution panal.. thats why i figured stator.. it probably is a 50cent wire thats screwing me all up.

 

[MostlyHrmlss]

Re: "CDI" or "rectifier" common problem?

Here's a wiring diagram for my motor, yours is probably close. Colors may be different.

 

[roscoe]

Re: "CDI" or "rectifier" common problem?

Here's a wiring diagram for my motor, yours is probably close. Colors may be different.

Sorry, this does not match his motor.
Nor does he have the 2 cd modules as on your motor.

oneman's motor has the thunderbolt ignition system with a switchbox with terminals, the cd is contained within the switchbox.

Looks like this:

Clymer Force repair manual can be found online or on ebay.
Here is the Clymer:



http://cgi.ebay.com/ebaymotors/ws/e...405&ua=M*S?&itemid=170531053603#ht_2530wt_941



Here is a factory manual:
http://cgi.ebay.com/ebaymotors/Forc...Motors_Manuals_Literature&hash=item2c5578ab3b



And no, you don't need to rope it.

 

[oNemaN]

Re: "CDI" or "rectifier" common problem?

WOW! thanks guys! i really apprecaite the help. im gunna give it a run through ill let you know how it works out..