No spark what to look for??

[Mercs and such]

i have a 75hp inline 4 and it will not run. Engine turns over, however the sparks are strong BUT only for 3 to 5 seconds MY mechanic said at first that my switchbox went to crap. Then they tell me its the stator and a broken carburetor I'd much rather get some logical explinations from you guys before I shell out $700 on something i can do myself for much cheaper.

What do you guys think? stator or switchbox or something else???

Mercs and such

 

[achris]

Re: No spark what to look for??

In order to properly diagnose ignition problems on outboards you need a DVA meter. A DVA measures peak voltage. A standard multimeter will measure either Average voltage or RMS voltage, either of which are not the output of outboard ignition systems.

I am in the process of designing a DVA adapter for as standard meter. You are the 4th person here in the last couple of weeks with ignition problems, so it looks like there is definitely a need for a cheap, easy to built DVA adapter...

Stay tuned.

In the meantime, let us know the year (or better, serial number) of your engine. That way we can identify the style of ignition system you have and be able to point you down the right diagnostic path.

Chris......

 

[Faztbullet]

Re: No spark what to look for??

Disconnect the blk/yell wire from switchbox(pack) and retest with plugs removed. If it fires all the time you have a wiring problem(keyswitch,mercury killer switch,harness) If not disconnect the yellow wire from rectifier and retest,if ok replace rectifier. If still failing remove stator lead and ohm test them with meter.. (see link below)
http://outboardparts.com/troubleshooting/troubleshooting11.htm

 

[Mercs and such]

Re: No spark what to look for??

Achris, thanks for the help! god luck with the adapter too! I will check that out soon. Let me know how the adapter went as well!

Fasztbullet, sounds like the right wires however, the shop has it and I cant do anything with it right now. Currently, I bought a new rectifier, my manuel says theres a wire leading to the "terminal block"??? I do not have one of those on my engine and I think i need it

Im still confused. I pay $87 for them to tell me that they checked the output on the wires and the only one that was messed up was the swithcbox. Then, they tell me its NOT the switchbox and the stator/trigger????

Mercs and such