Won't start

Joined
May 7, 2010
Messages
6
I have a '95 40hp 4 cyl Mariner. Had the carbs rebuilt and ran fine. I let it sit for a day and now no fire. Turns over fine and getting fuel.
 

Can't Cast

Seaman Apprentice
Joined
Feb 13, 2010
Messages
31
Re: Won't start

It could be a corroded wire terminal or loose wire somewhere. Check your wiring connections and see if anything looks iffy.
 
Joined
May 7, 2010
Messages
6
Re: Won't start

Kill switch is working properly. I am getting voltage to the ignition module but not to the coils.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Won't start

A short to ground anywhere along the kill circuit will cause a 'no spark' et the stator and trigger voltages to the module will check out fine.

Dis-connect the black wire w/yellow trace from the ignition module and retest for spark.
 

Wingedwheel

Lieutenant Junior Grade
Joined
Jun 16, 2009
Messages
1,071
Re: Won't start

I'm not sure exactly which model you have, but is there a fuse for the ignition module?
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Won't start

Are you cranking the motor WITH or WITH OUT spark plugs in?

Your ignition has a minimum cranking speed of 300 RPM, a low battery, aged/corroded connection on ANY cable, or an aged starter motor will slow cranking speed and fail to spark.

Remove the plugs, it may crank faster and have spark, then look into the starter system.
 
Joined
May 7, 2010
Messages
6
Re: Won't start

plugs are al out and i have brand new battery, I bekieve I have isolated it to the switchbox.. I have voltage coming into the switch but no voltage out..
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Won't start

Voltage to the ignition module must be measured with a DVA Meter or DVA Adaptor on a standard VOM, using just a VOM WITHOUT the DVA Adaptor may give you false readings, i.e., voltage but NO amperage, and the ignition still will NOT function.

Just because the battery is new does NOT guarentee that cranking speed is adaquate, poor connection on the other ends of the cables, or the starter cable, or within the solenoid, or dirty brushes in the starter can still be a cause of slow cranking speed and LOW DVA Voltages to the ignition module.

What are the voltages you measure and how did you measure them?

Generally, a motor will NOT lose fire on ALL cyl's all at once, except for slow cranking speed. That does not mean that it is impossible for the module to be bad.
 
Joined
May 7, 2010
Messages
6
Re: Won't start

replaced switch box(power Pack) Engine runs great.. Thanks for the trouble shooting advice.
 
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