Help! Mercruiser I/O with no spark
Christopher Rugg
I have an 84 mercruiser 3.0 lit 140hp inboard/outboard(old style
ignition-points, etc). It had extensive servicing and then winterized
last fall. I took it out of storage this last weekend and just put a new
carb on it. It turns over, but won't start. It didn't even catch which
leads me to believe that it not getting any spark. I threw a timing
light on the plug wires, then turned the engine over. This confirmed my
thought that there wasn't any spark. I tried the timing light on the
lead from the coil to the distributer and still did not see any activity
from the coil. I bought a new coil and tried that, but no go. There
still isn't any spark.
Does anyone here have idea what I should look at next? Someone said the
points may need to be replaced or even the condenser, but wouldn't I
still see activity or flashes from the timing light on the coil lead
even if they were bad? Thanks in advance.
chris....
WildestDream
you have 2 bad wires, put a plug in the end and ground it,check for spark at
the plug. check to make sure they didn't ground the points ( put them on the
wrong side of the connention witch I dought if he was a pro) hope they
replaced the connection, take it back end tell them it never started after
they did the work, I would do that first. goodluck
"Christopher Rugg" <cr...@none-destek.net> wrote in message
news:3F0046E7...@none-destek.net...
gatt
> This confirmed my thought that there wasn't any spark. I tried the timing
light on the
> lead from the coil to the distributer and still did not see any activity
> from the coil. I bought a new coil and tried that, but no go. There
> still isn't any spark.
I think I wrote this message just last week! Same motor, same problem, same
symptoms.
In my case, the solution was to clean the shift-interrupt switch which is
located at the top of the engine block. When you shift from forward to
reverse, it's the thing that momentarily kills the ignition and the switch
is just a little black momentary on the top of the motor. I sprayed mine
with electric cleaner and pushed it many times and it's working fine now.
I'll probably replace it next time I get paid, but I think it just had
moisture or crud from the winter built up in it.
Good luck.
Chris Gattman
Portland, OR
WildestDream
"gatt" <ga...@juggFUerbot.com> wrote in message
news:h%3Ma.2487$JY1....@nwrddc01.gnilink.net...
Christopher Rugg
located? I haven't had much luck finding a diagram on the web that shows
me what it looks like or where it is located. Also, just to double
check- this switch would still allow the engine to "crank over" while
killing the ignition? Thanks agian for the help.
chris....
Christopher Rugg
Christopher Rugg wrote:
>
> Thank you for the info! Can you tell me where on the block this is
> located? I haven't had much luck finding a diagram on the web that shows
> me what it looks like or where it is located. Also, just to double
> check- this switch would still allow the engine to "crank over" while
> killing the ignition? Thanks agian for the help.
>
Ok, Nevermind! I think I am all set on this. I did find out that it is
located in the top of the engine mounted against the shift rod.
thanks
chris....
Calif Bill
help very much when out boating for the weekend and something minor occurs.
Trouble shooting spark checklist:
1. Check if you have 9-12Volts at the + side of the coil. Use a Volt Ohm
Meter for this.
If no, go back along wire path and find out if shift switch is stuck, of
corroded connection.
2. If Yes, look at (-) side of coil and see of goes between voltage and
ground when cranking engine. Use either the VOM or a test light. If light
always on, points are not closing. If always off, points are not opening.
If going on and off while cranking, then coil is probably bad.
Bill
"Christopher Rugg" <cr...@none-destek.net> wrote in message
news:3F01A0F9...@none-destek.net...
gatt
Did it solve the problem? The engine will crank via the starter, but there
will be no spark.
Hope things are working. I'm tied off next to my friend's 47-foot ketch that
we took sailing on Sunday. Way cool. Today we took my boat out and landed on
an island. I jumped right out of the bow and right onto a submerged board
with a huge rusty, river-soaked nail in it which went straight into my foot
and hurts like a mother right now.
Tetanus shot in the morning, then I'm giving this cute 23-year-old
fan/friend of mine a ride up the river. After that I'm going to try
rebuilding the carburetor to solve a minor surging problem.
-c
Christopher Rugg
> Did it solve the problem? The engine will crank via the starter, but there
> will be no spark.
I won't know until this weekend when I go down to Cape Cod where the
boat is kept. thanks for the help everyone.
> Hope things are working. I'm tied off next to my friend's 47-foot ketch that
> we took sailing on Sunday. Way cool. Today we took my boat out and landed on
> an island. I jumped right out of the bow and right onto a submerged board
> with a huge rusty, river-soaked nail in it which went straight into my foot
> and hurts like a mother right now.
OUCH!
> Tetanus shot in the morning, then I'm giving this cute 23-year-old
> fan/friend of mine a ride up the river.
Oooolala ;-p LOL! Enjoy the boating!
chris....
