Intermittent Spark Problems

[steam_mill]

My mercury 7.5 hp is having some restart problems.<br /><br />Are intermittent spark problems common?<br /><br />When the motor is running, it runs well. Excellent spark. I can disconnect either spark plug wire, and motor will run with less RPM.<br /><br />When I can't restart, the one time I tried, I could not see a spark on the disconnected plug wire.<br /><br />It was probably me.<br /><br />If I have an Intermittent spark problem, what should I do to confirm it?<br /><br />Tx.<br /><br />Joe

 

[Laddies]

Re: Intermittent Spark Problems

need a serial number or year

 

[steam_mill]

Re: Intermittent Spark Problems

Forgot...<br /><br />s/n is 7106267 which is a '77 I think.<br /><br />It's a canadian motor.<br /><br />Tx.<br /><br />joe

 

[Laddies]

Re: Intermittent Spark Problems

Your system can be checked with a DVM the stator should put out 180 v. the trigger about 5v. and 180v. at the coil

 

[steam_mill]

Re: Intermittent Spark Problems

DVM: Digital volt meter?<br /><br />Alternating current I think?<br /><br />Can you be more specific on how to do this check?<br /><br />I really appreciate it...<br /><br />Tx.<br /><br />Joe

 

[Laddies]

Re: Intermittent Spark Problems

Sorry I wasn't very clear Direct Voltage Meter or DVA Direct Voltage Adaptor that lets you read peak voltage with a standard voltmeter

 

[Saskatoon2005]

Re: Intermittent Spark Problems

Is there any way to hook up a voltmeter to the unhooked sparkplug and ground to see how much voltage is coming to the sparkplug end?<br /><br /> I am having the same problem with my mercury right now as well.

 

[wilde1j]

Re: Intermittent Spark Problems

Don't want to measure there 30,000 V +!!! Use a spark gap tester ... should get a blue spark across a 7/16" gap.

 

[Saskatoon2005]

Re: Intermittent Spark Problems

Thanks for the advice...WildeOne...Ooouch!