link and sync question

[ColdFire]

Just finished rebuilding the ignition system on my 87 115hp inline 6 merc, and I am getting ready to link and sync but I have a quick question. You have to remove all of the plugs except 1 but I thought I read on here somewhere that you shouldn't turn it over unless you have a plug or spark tester hooked up or it could damage the switch box? Am I just gun shy after forking out all the $$$ for two switch boxes and a stator, or is it safe to leave the plug wires hanging for the first timing check?

I am pretty sure I know the answer to this one but just to be safe

 

[Chris1956]

Re: link and sync question

Cold, Normally I remove the five plugs, install them in their wires and boots, tape the steel bases together, and tape them to the block so they are all grounded. This protects the switchboxes.

 

[ColdFire]

Re: link and sync question

That is what I thought... better safe than sorry.

Thanks

 

[j_martin]

Re: link and sync question

I wired together 5 screws with spark plug nipples threaded onto them and an aligator clip on the end of the wire. I just put the plug boots onto the screws, ground the whole works to the frame, and the ignition is protected.

The voltage has to be limited. The spark plug normally holds it to 10 KV or so, 0 works just as good.

hope it helps
John

 

[tashasdaddy]

Re: link and sync question

http://forums.iboats.com/showthread.php?t=168855

 

[Stinkin_V8]

Re: link and sync question

I don't see any mention of this in the FAQ writeup above - not that I don't believe you guys!

What kind of damage can occur and how much of a chance of it happening is there?

 

[hkeiner]

Re: link and sync question

What kind of damage can occur and how much of a chance of it happening is there?

Seems more like an academic question. Most of us probably would not try it to determine exactly what kind of damage can occur and certainly would not do it often enough to determine the frequency of it occuring. Ground the wires to be safe unless you want to experiment for yourself. You might get responses from some on this forum stating that they don't ground the other wires, but I think that most would agree that grounding them is the right thing to do and it is not a lot of trouble.

I have found that the advice and tips I read on this forum are invaluable and they have probably saved me a few times from making mistakes.

 

[Stinkin_V8]

Re: link and sync question

Sorry, I should have been more to the point - I have already unknowingly been cranking my engine over with plug wires flailing.. Have I baked my switch boxes already? Is there an event that I might have noticed that would indicate that I've fried some expensive parts?

If I correct my ways, is there a chance that my '80 L6 will still be OK? I just didn't know about this before!

 

[hkeiner]

Re: link and sync question

Sorry that I took your previous question literally. If you are still getting a good spark on all of your cylinders, you are probably OK. If you fried the switch box, I believe that you would be missing spark on one or more cylinders and the motor would not be running well.

If your are missing a spark on one or more cylinders, the shop manual will have instructions on systematically troubleshooting the ignition system. You would need an ohmmeter and voltmeter (multimeter) to do some of the tests, while a DVA meter is needed for other tests. Alternatively, some people move parts around and/or switch wires around to see what happens to the spark and then conclude which component has failed. There are many posts on how to do this. I can't help you there as I generally use meters to troubleshoot.

Good luck.

 

[j_martin]

Re: link and sync question

What not grounding the plugs does is it allows the firing voltage to get to an extremely high voltage. Usually the insulation and components can take it, but if they fail, the failure is permanent.

Here's the scoop, as I see it.

It's probably about a chance in 10 that you'll fry something without the strapping.

If you've done it once, the odds are less that the second time will hurt it, but not completely safe.

The cost of strapping is a few bucks, even considering time.

The cost of a switchbox or coil is,....eerrrr a bit higher.

That's why us po folk strap them if we remember to.

John

 

[ColdFire]

Re: link and sync question

Strapped'em linked and sync and I am back on the water with a happy tower of power.

thanks