Spark plug grounding

[further]

Hi all,
It's been a long winter and I'm finally getting ready to get out and start up my 2nd year of boating. I need to do a compression test and have never done one on my own. Any pointers that you all can provide would be great. I'm new to all this and have limited mechanical knowledge however, I'm trying to learn and do the basics on my own. I'm especially confused on exactly how to ground out the plugs to the block. I understand that I should remove the safety lanyard to disable the ignition, put it in cold start wot position (mine is a pull out type), remove the plugs and stick them back in the plug wires, but not exactly sure how or where they should be grounded. Thanks all for your help.
Happy Boating!!

 

[pnwboat]

Re: Spark plug grounding

Helps if you mention what year and horsepower of your motor.

The only time you need to ground the plugs is when you are setting the timing. This requires that the ignition system be active and sending voltage to the plugs.

If you're doing a compression check, there is no need to ground the plugs because you are pulling the kill switch lanyard to disable the ignition. Remove all of the plugs, insert the compression gauge and crank the motor over for 5 or 6 revolutions. Repeat for each cylinder.

 

[further]

Re: Spark plug grounding

Its an 1988, 85 hp - sorry bout that. Thanks for the info.

 

[JB]

Re: Spark plug grounding

Check out the Engine FAQs forum, Further. Detailed instructions there.

Good luck.

 

[further]

Re: Spark plug grounding

Thanks JB, I just went in the Engine Faq's forum and couldn't find any instructions on this. Can you point me in the right direction?
Thanks Much

 

[erikpn]

Re: Spark plug grounding

Throttle position doesn't matter. You are not starting the engine. Grounding the plugs doesn't matter. None of the plug wires or plugs are getting voltage. All you have to do is remove the lanyard, remove the plugs, thread in the compression tester into the plug holes and crank it over a few times. Repeat in each other hole. Shouldn't take more than 3 minutes.

 

[JB]

Re: Spark plug grounding

Sorry, further. It is there now.

http://forums.iboats.com/showthread.php?t=391323

Good luck.