Testing ignition system - 1980 Merc Inline 6 Thunderbolt Ignition

hempfarmer

Petty Officer 3rd Class
Joined
Oct 13, 2009
Messages
80
Hi there,

Just looking for some advice on how to check my ignition system. My boat stalled towing a skier at 4000 RPM and after this it won't idle very well and WOT is now 4000RPM instead of 5400 RPM. Sounds like I am missing a cylinder. My mechanic was testing my stator this spring and he found it was just within specs but felt the readings didn't hold very steady so I kind of expected it to go at some point.

I don't own any of the tools so I am going to do the following:

1. Buy a spark tester and run test.

2. Buy a DVA meter to verify if my CDI stator is within their specs. I am going to do this without actually running the engine.

Can you think of anything else I can check on my own? Oddly I am hoping my stator fails the test so I can swap it and the switchbox out. More piece of mind knowing those parts are new anyway.

Thank you.

Russ
 

canoemang

Petty Officer 1st Class
Joined
Apr 9, 2011
Messages
350
Re: Testing ignition system - 1980 Merc Inline 6 Thunderbolt Ignition

That is a proper spark tester. Most parts stores have them same or similar for $10.00

Here is a Ignition test guide from CDI:

cdi ignition testing
 

canoemang

Petty Officer 1st Class
Joined
Apr 9, 2011
Messages
350
Re: Testing ignition system - 1980 Merc Inline 6 Thunderbolt Ignition

Go grab one from Ebay..

here is the one i grabbed earlier this season.. works great.

DVA METER
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,929
Re: Testing ignition system - 1980 Merc Inline 6 Thunderbolt Ignition

Check your compression first. If it is good, proceed to the spark test.
 
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