Cyl #4 not firing

[reload]

Re: Cyl #4 not firing

In post number 36 you say you no spark at all now, is this correct or is it 2 & 4?

 

[TAC_Double]

Re: Cyl #4 not firing

I have no spark at all now. Started with just 4 than 2/4 and now all 4...

I tried swapping back to the old power pack... no change

 

[reload]

Re: Cyl #4 not firing

Sounds like you need to go back to square one. Pull everything lose. Clean everything up, check all connections. See what you got. I think it is something loose or misconnected or disconnected. Things just don't happen this way. Check everything again, start with the stator, regulator, power pack. I think you will find it. Give it one more try before calling the expensive shop.

 

[TAC_Double]

Re: Cyl #4 not firing

Thats what i need to do... I have the shop manual, but it does not outline the tests very well. Talks about DVA voltages, Which for what I have read, I can not check without buying a special tool.

Is there any place that outlines the tests in easy to understand tests?

Is it possible that something has shorted keeping the ignition from producing spark? Kill switch or somthing along that lines?

 

[ezeke]

Re: Cyl #4 not firing

edit

 

[TAC_Double]

Re: Cyl #4 not firing

Did'nt know that the plugs needed to be out. Battery is fully charged.

 

[ccnstlr]

Re: Cyl #4 not firing

Plugs out would allow the motor to spin at a higher RPM due to no compression backpressure.

DVA is peak reading. CDI Electronics makes an adapter that works with a Fluke or other good meter that will allow it to read peak. Part # is 511-9773 or 511-9773NL without leads.

I'm with 'reload' in that it seems more like an issue of wiring misconnected, disconnected, or even deteriorated in one of the Amphenol connectors. Motors of age seem to have the deterioration problem. I've had it myself on an 88 model.

You could try disconnecting the black/yellow kill wire at the pack. And also disconnect the large wiring harness plug at the motor (usually large and red). You'll have to jump across the starter solenoid to turn it over. If it fires, then the key or kill switch is causing your 'no fire at all' situation.

I've also read some articles concerning air gap of the trigger sensors??? Don't know if it applies to your model, but it seems to apply to mid 70's models. Maybe one of the more seasoned could chime in on that.

 

[ezeke]

Re: Cyl #4 not firing

edit

 

[TAC_Double]

Re: Cyl #4 not firing

Well, I disconnected the red harness plug and checked for spark again. I set the gap on the tester at about 1/4in. I got a very weak spark on #3, but only got 3 or 4 sparks before it was gone. No spark on any other cylinder.

Does this show anything?


I am headed to get a puller and I am going to pull the flywheel and take a look. It's about the only thing I have not done trying to figure this out.

 

[ccnstlr]

Re: Cyl #4 not firing

Have you checked the alternator circuit for 12volts? This would point toward the stator being bad. Mechanics seem to think they never go out, but I've changed them on two motors recently. One was a very weak few sparks then no fire situation as yours is (Ohm reading was way off the scale), and the other was the alternator not charging. You can look for the ooze when you get the flywheel off, but that's not always the case.

 

[ccnstlr]

Re: Cyl #4 not firing

Check this place out. I was looking here and run across another set of test procedures in lamens terms.

May help for ya.
http://www.brokeboats.com/ignition3.html

 

[TAC_Double]

Re: Cyl #4 not firing

Well,

I want to thank you all for the help. I have tested and checked everything but the DVA voltage, which I am unable to test. I guess it's time to send her to the shop.... As much as I hate to say it.


Thank you all!

 

[TAC_Double]

Re: Cyl #4 not firing

OK,

Here is a little update and I hope this yeilds some info. I called the shops around here, everyone is 8-10 weeks behind. I got one to loan me the DVA voltage adaptor so I could do some testing.

I redid all of these tests.

http://www.boatpartstore.com/page30.asp


Here is what I found.

2. no spark
3. no spark
4. Stator resistance is 633
5. DVA out from stator was 17.51????????????????????????????????
6. 11.7 and 11.8 for the timer base resistance.
7. DVA output from timerbase was .746 (1-3) and .684 (2-4)


So what does that tell me? bad stator?

 

[TAC_Double]

Re: Cyl #4 not firing

Anyone?

 

[tschamp20]

Re: Cyl #4 not firing

looks like you inherited my bad luck at not getting replies when you most need them.lol

 

[reload]

Re: Cyl #4 not firing

Man I wish I could help you but I don't know enough about the DVA voltage, never had to check it. High Trim or someone else will be along hold tight.

 

[TAC_Double]

Re: Cyl #4 not firing

???

 

[loujoe]

Re: Cyl #4 not firing

Hey Dude the cylinder that is not firing. Remove that coil and put one of the coil's that is firing. If it fires buy you a coil and forget the rest of that stuff. Party on

 

[loujoe]

Re: Cyl #4 not firing

You need a timer base. DVA= digital voltage adaptor allows your meter to read pulses of 500 dc/volts. Your normal digital cannot read these pulses. You will need to drop about 100 bucks for a cdi adaptor with cables. Some where within the wiring of that timer base or connector there is break, split, either way it produces an open. Replace it and shel pur. trolle

 

[Toddo1]

Re: Cyl #4 not firing

The stator creates the charge for all cylinders to fire. The Timer Base send the signal for when each cylinder fires. If it isn't the power pack, coils or plug wires, it almost has to be the Timer Base.

You can check it with an ohm meter. The specs should be in your manual. Also check for loose or broken wires at the connectors as this is a common problem area.