Do I have a weak spark?

[woodnknots]

Okay, I got a new CD, and got my spark back to cyl #3. Now my engine is running exactly as it did when I thought I had bad gas!!
It runs for anywhere from not at all to about 15 seconds, with intermittent sputtering (lots of extra smoke when it sputters, like all the cylinders are truely firing for that instant), till it just quits.

#3 cyl (top one) has only black power type substance on the plug (completely dry).

#1 and 2 (bottom and middle, respectively) are wet.

So I was thinking maybe I had weak spark on 1 and 2. I first swapped CD boxes, hoping that the front box (original with motor, as far as I know) was weak and the new box I got from the salvage would fix that problem.
No joy on that.

So I figured a good way to figure out if it was a weak coil would be to swap 3 and 2 triggers and plug cables to see of 3 would be wet while 2 was dry. No luck, and no appreciable difference in how the motor ran.

Should ANY of my plugs be wet? My dad says no. I seem to remember when I first got the boat (about 2 months ago) that all my plugs were wet to some extent when I pulled them.

If my plugs should all be dry, then what else might cause my spark to be weak? Have I done the right things so far? Does anyone have any more thoughts or theories?

One more thing, my dad thinks that I should consider replacing the ignition system totally (stator/CD's/coils). Can a stator cause a weak spark? I am about 99% positive that this is an electrical problem.

 

[Kajun37]

Re: Do I have a weak spark?

any one of your electrical components can cause a weak spark...and yes it does sound like an electrical problem.....have you done a compression test on it yet?


i live in norfolk also..off tidewater dr..

 

[Kajun37]

Re: Do I have a weak spark?

what year and model is your force?

[whisper uid=86548]

email me at kajun29 at yahoo.com i might be able to help you fix ya motor.. i have spare force parts from a 85hp and 125hp force

[/whisper]

 

[roscoe]

Re: Do I have a weak spark?

Cylinders are numbered 1-2-3 top to bottom.

You have a 2 cycle motor.
ALL your plugs should be wet.
You are mixing TCW3 oil in the gas, aren't you?

You may have a spark issue, but you definitely have a fuel/carburetor problem on the top (#1) cylinder.

If it is dry, it is not getting enough lubrication, which translates to not enough fuel getting to the cylinder. That motor won't last long in that condition.

Rebuild those carbs first, don't mix the parts from the different carbs.

 

[woodnknots]

Re: Do I have a weak spark?

Cylinders are numbered 1-2-3 top to bottom.

You have a 2 cycle motor.
ALL your plugs should be wet.
You are mixing TCW3 oil in the gas, aren't you?

You may have a spark issue, but you definitely have a fuel/carburetor problem on the top (#1) cylinder.

If it is dry, it is not getting enough lubrication, which translates to not enough fuel getting to the cylinder. That motor won't last long in that condition.

Rebuild those carbs first, don't mix the parts from the different carbs.

OKay, now I'm confused. I thought the same thing about the top to bottom numbering thing, but the CD units are wired according to a 1-2-3 from the bottom. I started to think that this might be an abnormality after looking at the wiring diagram in my SELOC manual. It shows 3 in the top position as well. Until this problem, this motor ran very smoothly in the wiring configuration it was in when I bought it (2.5 months ago). Is it even possible for it to run smoothly like that if 1 and 3 are reversed? The wiring is set up EXACTLY like the diagram, only the physical location of # 3 is different. I'm afraid to go swapping all the wiring around just to find out.

 

[roscoe]

Re: Do I have a weak spark?

I wouldn't worry about the numbering thing.
If it was running, it is wired correctly.
The more you read in that Seloc manual, the more mistakes you will find.

Much more important is to get that fuel delivery problem fixed, before you score the cylinder or bust a ring.

Very possible that the "bad gas" plugged up the jets in the carb.

 

[woodnknots]

Re: Do I have a weak spark?

Okay, I decided to try and plug the coils the way the manual says, before I pull the carbs...


Holy crap, this thing runs like a TOP!!!

It has never run this good. When I got it, I had a big problem with mid-range coughing, and that is completely gone now. I have good smooth operation as far as I am comfortable with running it up on the muffs!
I'm on my way to the water to try it out. I'll let everyone know how it goes!

 

[woodnknots]

Re: Do I have a weak spark?

Got it on the water, no problems whatsoever. I still need a new prop, but that's on the way. Boy, that's a big load off my mind!!!! Thanks again for all the help!