DEMON's BACK!!! ignition issue?

[autorot8]

Ok...dont know what to do. (scracthing head)

I installed a new electric fuel pump, water filter/seperator...and still I have a demon!!!

Here is what happened....

Engine seemed to run hotter than usual. It got up to 220, i like it no hotter than 160. It has a 140 thermo. (i think). She seems to have the temp, right in the middle of gauge, but today it was moving past that.

She ran well the other day, but here is what happened on Saturday..

She ran well in the morning puttering out, coming back in, she began to run hot, i keep creeping throttle from 1/3 to 1/4 to keep temps in the 180 or so range. I even shut it down a couple of times for her to cool down.

She seemed to be missing (misfiring a little)...like it would not fire on a cyclinder occasionally...Then she began to run a little rougher, lost some power, throttle changes where doing little to rpm...then she sputtered out and quit.
I still had sails up, so i was ok...15 minutes later, she started back up and i motored her into the slip perfectly, without incident.

I am wondering what the heck is wrong with my motor?

should i start thinking this is a ignition issue. I am gonna pull the plugs in the morning.

Should I consider an electronic ignition?
A new coil? both?

Steve Latour
Columbia 28

http://66.238.15.120/sinderella/

[smosher]

I KInda think you might have something blocking the water flow or a leak which causes less water flow.
I replaced all my hoses and the impeller and at idle my temp will go up. If I bump up the throttle the temp goes down. I am assuming this to be due to the increased water flow

If you haven't I would pull the thermostat and see what the temp does and when its out I would also do the acid flush.

I don't think the coil and or electronic ignition would cause
the motor to overheat.

I have a 140 thermstat and with the ocean water @ 60 here in New England mine run's consistenly between 120 - 140. With the indigo prop I run it about 1/3 throttle for 5 - 5 1/2 kts.

[autorot8]

heating and ignition

I think I have a couple things going on...I agree water flow is likely part of my problem... I agree with you, an increase in RPM, should increase water flow, thereby cooling engine more...but that was not the case...

I will be pulling off some water lines today to see what they look like. The impellor was replaced a couple of months ago. I have always had a decent amount of water flow...I will review today.

I do also think that the misfiring is a result of an ignition related problem. I cant et understand what would cause the reduction in power, misfiring and subsequent engine quitting.

[Terra254]

How about the coil

I was having a similar problem with the engine cutting out after an hour...especially when in gear and under load. It would not restart for about 30-40 minutes. I replaced the coil and so far my demon seems to have gone away.

Your engine also seems to be running hot...a acid flush should help that problem as well. I find I need to do an acid flush once a summer.

[Unregistered]

Try a coil

Hi All,

I had similar symptoms, which led me to this forum. She would start and run very well, but under load for extended periods of time, there was a period of bad running and then it would shutdown. Restarting was impossible, crank and crank and crank - nothing but the smell of fuel and the looming leward shore. After a 'rest' it would restart and run perfectly... again until it got 'tired'.

Last year I replaced points, condenser, cap, rotor, plugs.. and although this seemed to correct the problem, I don't normally run the engine that long. Anyway, the problem resurfaced and I came back here and read every post I could find on the shutdown 'bug'.... I'm not a mechanic, but will share my experience here for those of us who are still experiencing shutdowns and may benefit from my information.

I did the following which I believe fixed my problem.

I checked for a bad connection on the back of the instrument panel. I verified the ignition switch wires, ammeter wires, and all other gauges had good clean contacts. (A bad connection there can cause a failure in the primary ignition circuit.)

I checked the breaker points contacts to see if they were pitted. (If the gap is too small, sometimes heat expansion can cause them to remain closed and therefore stop ignition). They were not, so I rechecked the gap and they were fine.

I replaced the ignition coil with a new one, (be sure to get the right type, mine was a resistor-type). I cleaned and greased the contacts on the wires which connect to the coil. I also found a connector on the alternator lead which I cleaned, greased and reconnected (I read that a bad coil can quit when hot, also a bad coil resistor - if present - can do the same. I also read somewhere that dirty/corroded connections can sometimes work when cold but fail when warmed up.. not sure where)

For good measure, I also installed a new set of ignition wires.

The grease I used on all connections is 'dielectric' grease, or 'tune-up' grease. I scuffed all the wire connections with some emery paper and coated them with a thin film.

I took the thing out and ran it hard for over an hour - much longer than the 'normal' failure cycle. I believe the coil fixed the problem, and now that my oil pressure and ammeter gauges seem to be working better (the oil gauge never worked), some bad or 'slightly bad' connections seemed to be present as well.

One other detail... For your troubleshooting, before you fix anything, it may be of value to take a friend out with you so that when the thing shuts down, you have someone to help you troubleshoot while the failure is present. (promise of beer can help.. or you could pretend there is no problem, and you are just taking them out for a ride in your boat...

I was hunting down an ignition problem not only because I could smell gas when cranking, but also because I pulled a lead off of a spark plug while a friend cranked the engine and found no spark during failure. A few minutes later, during cranking, a spark returned and the engine ran. The failure was painfully intermittent.

Hope this helps!!!!

Jeff
1972 Grampian 30 - Auxillary Power supplied by the 'Atomic bomb'.

[Don Moyer]

Jeff,

Great report!

Don

[autorot8]

Some new parts...seems ok...but..

I installed a new coil and points this afternoon. Thanks again Moyer Marine! and for all of the forums members for the awesome tips and advice!

I have a couple of concerns after fire-up, warm up and load testing today.

Here is what I did this afternoon;

After installing new points (setting gap) and installing new flame thrower coil.

I pulled all the plugs, number 1 was the blackest, the other 3 were ok looking. I poured a little Marvins Mystery Oil into each plug, turned engine over a couple dozen turns (with no coil wire installed), I then poured in a little more oil into plug holes. I cleaned excess oil off head as best as possible before re-installing plugs.

She started right up and ran much smoother across all RPM ranges. I let her warm up with about 25% throttle for about 10 minutes, then I kicked her into reverse while tied in slip to add some load...here's what happened.

The temp guage after 10-15 minute warmup was 160,
then after 10 minutes under load (reverse, 25% throttle) the temp went almost to 200...(never higher) I left it under load for 20-25 minutes.
A little throttle adjustment up, temp settled back down to 185. Still a little hotter then I like/want. When the throttle went down, the temps inched closer to 200 again.
When I took the load off of engine (neutral) the temps went back down. At idle in neutral, she went back to 160 in a couple of mins, from almost 200.

When she got hot, the number 2 plug was boiling (bubbled) (water or oil? not sure.)
I turned off engine, pulled plug, cleaned it up again, reinstalled plug, fired it back up, only to have it boil more in a few mins?
bubbles would pop as I increases RPM a little...hum? leaky?

So my symptons;
higher running temps (especially under load),
dirty number 1 plug,
a little more smoke in exhaust than I like to have,
bubbling number 2 plug...
eek...

I guess I should do an acid flush asap...this might clean out some gunk inside engine, maybe allow me to run a little cooler...(i do get good flow of water out exhaust though)

or is my high temps the result of something else? timing? running rich maybe? (would this explain dirty number 1 plug?)

New Parts installed last 45 days:
-plugs
-points
-fuel pump
-fuel filter/seperator
-coil
-wires
-new fuel lines and tank and bulb
-impellor/gasket

running out of ideas now. I think I may have killed my demon (fingers crossed, cause she seems to run smoother and not mis-fire like she did before)
but I want to have peace of mind with engine (in slip) than have her die on me, when I need her the most (while out on the bay).

[Don Moyer]

One thing that seems to be certain from your report is that there is a small water leak on top of the head someplace just ahead of the plug well that collects the small amount of water which you see boiling off.

Don

[autorot8]

pull head...replace head gasket?

Don,
So I guess this means a new head gasket? I guess it's time to pull head and see whats the matter. Have a look and see...

Once I pull the head, anything in particular I should inspect/examine more closely? Areas in particular which point to a more serious issue?


I have a gasket and have time on sunday afternoon to pull head

[Don Moyer]

I wouldn't pull the head just because of the suspected water leak. You may be able to seal the water leak with epoxy. The first thing to do (which you won't be able to do nearly as easily after the head is removed) is to find the leak. I'd run the engine again and pinch off the water hose leaving the back of the manifold for a few seconds. This will increase the water pressure in your cooling jackets to approximately 18 to 20 psi and should enable you to find the source of your water leak.

Don

[autorot8]

did it!

I pulled the head and replaced the head gasket today.

I am glad I did, cause no. 2 was definetly burning a little water. the piston on no. 2 was clean, while the other 3 pistons were traditional black carbon.

Whole job took 2 hours. (most of it spent removing old gasket material off block and head).

The engine runs good and I will test her soon to see if my demon is gone!

The engine still seems a little smokey for my tastes...I wonder if it's blowby or running a little rich maybe?