No Spark at the Plugs?

[John115]

Quick run down, i bought a boat,took it out a couple times and it ran great! The last time i ran it, i cruised around the lake and had an awsome time. Brought the boat in, docked it on the trailer and headed to the house! I took it out the next weekend and she would not crank, not even a eccup! I've got a Manual comeing in the Mail and the parts store in this town dont have a compression tester to borrow some im ordering one over the internet. For know, i do know i am not getting any spark on none of the spark plugs. Can you guys give me some ideas while i wait on the manual. Thanks

 

[asm_]

Re: No Spark at the Plugs?

If she wouldn't even crank over, there is no need to check for spark. You are getting ahead of your self. Check battery connection to the motor first.

B

 

[Dave1027]

Re: No Spark at the Plugs?

It would help if you stated what motor you have. It would also help if you could be specific regarding your terminology. Does not crank to me means your battery is dead.

But if it is actually cranking but not starting and you have confirmed you have no spark then the first thing I would check is the wiring connections at the switchbox.

 

[John115]

Re: No Spark at the Plugs?

Sorry about that, it's a 1983 Mercury 115 hp 2 stroke serial # 6300804, and the motor will crank, just won't start. I checked for spark with an adjustible spark tester at 7/16 gap. No spark at any of the plugs. I've checked all the wiring at the switch box, everything appears to be good except for one wire that goes to the (idle stabilizer). I'm not 100 % sure that is the name of the part but i replaced the wire with new 12 gauge wire.

 

[asm_]

Re: No Spark at the Plugs?

I have the same motor.

You need to first make sure the mercury tilt sensor is not bad and preventing the switch box from firing.

After that, it's time to get a DVA adapter and start probing.

B

 

[Ski'nBlind]

Re: No Spark at the Plugs?

Weird, I have serial # 6300830

Read this for 9 amp stator. Lots of other info on the CDI website just made for you: http://www.cdielectronics.com/InstallSheet/174-5456.pdf

This will help chase wiring till you get your service manual: http://www.maxrules.com/oldmercs/Wiring/1966ona/37.jpg

Plus some other good info at his site: http://www.maxrules.com/index.html.

In addition to the manual you really need a multimeter with a dva adapter then it becomes pretty easy to test the ignition parts.

 

[John115]

Re: No Spark at the Plugs?

Compression test results, from top to bottom- 95, 95, 100 ,95 ,100 ,95. Do i have something to work with or am i the proud owner of junk?

 

[Dave1027]

Re: No Spark at the Plugs?

Compression is not your problem. Nobody advised you to do a compression test. What are you not understanding about the replies you have received so far? Your thread title says "No Spark at the Plugs". Compression has nothing to do with spark.

 

[asm_]

Re: No Spark at the Plugs?

Well, it doesn't hurt to check the compression. However, it does, indeed got nothing to do with spark.

Like I said, check the tilt mercury switch. After that, making sure power is getting to where it's needed.

B