Safe to check compression w/out grounding plug wires?

[Dank]

Is it necessary to ground the plug wires, and if so what's the easiest way to do it (w/3 cylinders)?<br />I'm thinking maybe it's not that necessary since I've seen posts from knowledgeable folks recommending pulling plug wires while the engine is running...isn't that about the same thing, electrically speaking?<br />Any enlightenment is appreciated!<br /><br />('87 Yamaha 90)

 

[JB]

Re: Safe to check compression w/out grounding plug wires?

Hi, Dank.<br /><br />If you are jumping your starter and leaving the ignition key OFF, there is no problem.<br /><br />Electronic ignition systems sometimes don't like having nowhere for spark to go.<br /><br />Good luck.

 

[Dank]

Re: Safe to check compression w/out grounding plug wires?

Thanks for the reply, JB.<br /><br />Jumping the starter sounds like it might be easier than trying to get a decent ground on 3 plug wires. <br />Mind telling me how one goes about that?<br /><br />Or how do most folks ground those wires?

 

[JB]

Re: Safe to check compression w/out grounding plug wires?

Short wire (6" is plenty)of at least #10, clip on one end.<br /><br />Attach the wire to the small terminal on your solenoid. When you touch the other end to the large, hot terminal on the solenoid it should engage the starter. Don't let the wire touch anything else.<br /><br />Good luck.

 

[rickdb1boat]

Re: Safe to check compression w/out grounding plug wires?

Ya know what works real well? Use a simple wall light switch. Attach a wire(1' or 2') to each side of switch and put clips on the ends. Put the clips on the terminals and Just flip the switch on to crank it over and off to stop! Cuts out the sparking effect, too. Also useful for other things as well, such as working on Car problems, when you don't have anyone around to crank it! Bypassing questionable wiring and such!

 

[JB]

Re: Safe to check compression w/out grounding plug wires?

I like that, Rick. Neat idea.

 

[Hooty]

Re: Safe to check compression w/out grounding plug wires?

When attaching the jumper wire to the small terminal on the solenoid, be sure it's the "+" terminal. My starter solenoid has two small terminals, The "+" and a ground.<br />I use an old starter button for the switch. It's probably 40 yrs. old. Don't know if they even make them anymore.<br /><br />c/6<br /><br />Hooty

 

[Dank]

Re: Safe to check compression w/out grounding plug wires?

Thanks for all your help, guys.<br /><br />I love this board