Hi guys,

Swapped my engine over and now I am getting no spark to my plugs

I have + to my coils but no negative - if I put the multimeter to the + and ground to the chassis then I get throughput.

The - wires coming of the coils are yellow/blue and disappear to the wiring loom so I was hoping someone could tell me where they go

Cheers

 

OK - wires go to CDI have swapped it out with a spare - and no change !

Any ideas?

 

The coils don't have a negative, the plug is the ground. I am new here so would you please let me know what model we are talking about (the bike& old engine vs what the new engine came from) so I am looking at the right wiring diagram. The wiring coming from the Pulser coils changes with model and is likely where your problem lies. Would need some specifics to diagnose.

Models that share like circuits:

H,J

K,L,M,N

P, onward

P.S. In the name of K.I.S.S. please make sure your kill switch is set to run.

 

Hi Thanks,

The engine is off an 87 and installed on a 90.

It is only the engine that has been swapped out so all he electrics are from the 90

(Kill switch is set to run )

 

Then I would start at the pulsers. the 87 model has two where the 90 has one. Assuming your using the 90 spark unit I'll assume it is not reading the pulser signals correctly (or at all). Perhaps see if the 90's pulser can be put in the 87 engine.

 

Hey this isnt a time to be proud , so....

What a pulser and where would it be ?

 

ignition pulse generator Harry , left crankcase , times the spark

Seems the 87 is a bit different

LINK

Getting an education here too myself

 

I am not sure (didn't test myself) but if you ground the blue/yellow and yellow blue wires with a test light you should get a pulse/flash of light as the engine cranks if your spark unit (CDI) is getting a signal from the pulsers.

Black/white should always be hot (have 12v coming to it) if the kill & ignition switches are good.

Another thing I thought of is the pulser on the 90 engine is yellow & white/yellow wired. Make sure the yellow & white/yellow pulser coming from the 87 engine is in the same position on the crank as the 90. Otherwise you'd possibly be getting a spark on the exhaust stroke rather than the compression.

 

Cheers guys - I will check and report back in the morning

 

Hope ya keep some notes there Harry and some pics too , good candidate for a
spot in the how to section mate