88 Excel no spark

[elsanto67]

Just bought a boat with an 88 excel, i had the guy start the engine before i bought it, it started right up and ran fine. Got it home, had to re-wire everything on the boat, but i didnt mess with the engine wiring cause it looked fine. So, basically it wont run now, i have no spark, i've checked voltage off the chrage windings, i have 68 volts, but at the pulse coils i have about .6 volts. any ideas? i'm having problems trying to figure out why it died on a 10 mile ride from his house to mine, it did give me one burst like it was trying to fire, but nothing since. i'm thinking its something i'm just missing... thanks

 

[elsanto67]

Re: 88 Excel no spark

and all my ohm readings are good on the charge and pulse coils, but i just hooked up my buzzer after reading another post and found that it is buzzing, so i guess whatever is causing the buzzing is causing my problem?

 

[elsanto67]

Re: 88 Excel no spark

got the buzzer figured out, so if anyone can help with the spark issue, that would be great....

 

[rodbolt]

Re: 88 Excel no spark

if your getting a buzzer while cranking then check the stop circuit wiring.
if the white stop wire is shorting to ground while cranking the buzzer will sound on that model.
what kinda meter are you using for your voltage output tests?
and what wire colors are you checking?
are the circuits loaded or unloaded while testing?

 

[elsanto67]

Re: 88 Excel no spark

yeah, i figured out why the buzzer was going off and rectified that problem, it isnt going off anymore.

ive got a digital fluke 179, the coils are unloaded. for the pulser coils i am checking w/r - w/g, w/b - w/blue, w/y - w/br and i am checkiong them when they come out of the computer which according to my sheet should be 2 volts dc?

for the charge coil i am checking br - r, for low speed and l - br for high speed.

all my ohm readings were in range and nothing is shorted to ground as far as my digital shows. i've got approx 68 vac coming out of my charge coils which according to my book is a little low, but the pulser coils are supposed to have 2 volts, and i have checked them directly out of the coil harness and where they come back to the cdi, and the most i've gotten was .6.

and last but not least the white stop wire isnt grounded, the kill switch is removed, and i've gone as far as to remove the white wire and try it with no luck. but i am reading about 1,100 ohm on that terminal to ground, but i assumed i was reading through a coil or something in the cdi. idk, whats next?

 

[rodbolt]

Re: 88 Excel no spark

that engine still used an ADI CDI setup.
means that it will make spark simply by rotating the flywheel if the charge coil input is ok, the pulser coil(trigger) input is ok and the stop circuit is intact.
all the other sensors simply modify spark.
when reading charge coil or pulser coil outputs your actually reading an AC signal.
however you MUST use either a peak reading meter or a digital meter with a peak reading adapter or any test results will be flawed.
while yes your technically looking at a DC voltage output from the CDI its going to act like an AC waveform to to the rapid rise and fall times of the signal.
remember,spin a magnetic field past a coil and AC voltage is produced and must be rectified for DC.
charge coil voltage is rectified and stored in capacitors in the CDI unit,thats why they call it Capacitive Discharge Ignition.
pulser coil voltage is simply modified and fed to an SCR gate that allows the capacitor to discharge to the correct ign coil primary.
so whatever charge coil voltage you see input to the CDI is about what your going to see on the CDI output to the ign coils.
and this is where an analog meter like the CD77 is so handy,
you can actually watch the cap charge and if it cant discharge you will see the needle rapidly swing up then fade back down as the cap charges and there is no more potential difference.
I would physically remove the white wire from the CDI harness and retest for inputs and outputs.
if yours has the CDI mounted on the stbd side you can dissconect both the pink alarm wire that sends the CDI into RPM reduction and the white wire for the kill circuit.
after that if all inputs are good and no coil primary output most likly the CDI failed.

 

[elsanto67]

Re: 88 Excel no spark

yeah, i know all about what youre saying, i checked for ac and dc voltage in two spots on the pulser coil harness just to be on the safe side, before the computer and after the computer. the cdi that were talking about is the box thats starboard on the engine with all the terminals on it right? not the actual computer box on the back, or am i wrong?

anyway, i checked with my min/max on the meter, but i still think it happens too fast for a digital meter. i know that the charge coils had 68vac directly out of the coil wires. i know the white kill switch wire is not grounded, but i took it off and tried to start it anyway, i tried the pink wire where it went to the computer also, and it didnt fire. i will try them both at the same time and see what happens.

 

[elsanto67]

Re: 88 Excel no spark

ok, i tried it with the white and pink wires off, so what else should i check with the white wire off if i dont have an analog meter?

 

[elsanto67]

Re: 88 Excel no spark

and if i need one, where can i get a cdi, and about how much $$

 

[elsanto67]

Re: 88 Excel no spark

any other comments before i take her to a mechanic?

 

[elsanto67]

Re: 88 Excel no spark

problem solved, thanks for the help