Prop size.

[hanleyclifford]

I got rid of my Christmas Tree coil setup and love the look of the new bus bar tidiness and I agree with you 100% regarding too many connections in a system. Every connection = Loss. Whether that be voltage or Db of transmission. Perhaps it is most simply explained like this. If you put a light bulb on the end of a piece of cable and apply 12 Volts, then run the wire all the way around the planet and back to your switch, then turn on the switch. Do you think the bulb is gonna light up? Doh !

That would be one hell of a resistor.

[ndutton]

The Moyer coil is always preferable - it is sold by The Man with all the experience, integrity and guarantee that implies - nevertheless, it should be defended by a quality resistor.

And that's where we have problems. The Moyer coil is designed and manufactured to be used without the added complication of a resistor and all it brings (connections, bypass) with alternator output voltages up to a whopping and ridiculous 17 volts. To suggest it "should be" protected with a resistor is entirely counter to its design.

Yes, even with your 14.8 volt alternator voltage you could use a Moyer coil without any added resistance and have a rock solid and reliable ignition system. You ought to give it a try. I'll even buy you the coil with the condition you report back with a candid assessment after using it.

[hanleyclifford]

There is no problem

And that's where we have problems. The Moyer coil is designed and manufactured to be used without the added complication of a resistor and all it brings (connections, bypass) with alternator output voltages up to a whopping and ridiculous 17 volts. To suggest it "should be" protected with a resistor is entirely counter to its design.

Yes, even with your 14.8 volt alternator voltage you could use a Moyer coil without any added resistance and have a rock solid and reliable ignition system. You ought to give it a try. I'll even buy you the coil with the condition you report back with a candid assessment after using it.

since both of our approaches appear to yield satisfactory results. Two very different mantras: one comes from Pertronix (and the 4 amp max corollary); the other simply limits voltage at coil+ to 12 volts or less.............and ne'er the twain shall meet.

[ndutton]

.............and ne'er the twain shall meet.

I made the offer to hopefully entice you to at least try it, put my money where my mouth is so to speak.

[Shrek]

Disaster bites me again

I wont go into all the details but just as we were about to cast off today I heard my raw water pump impeller disintegrating as I had forgotten to turn on the supply valve. Took it apart and there wasnt a blade left on it. Removed some powderd rubber from the pump housing and bought and fitted a new impeller. Now I have only very small batches of water coming out of the exhaust port on the transom. How do I fix this. We did see some small pieces about 1/4 inch coming out but now none and not much water. Can we backflush and how ?

[ndutton]

Shredded rubber vanes migrate throughout the cooling system until they lodge somewhere and block flow. Typical locations are the elbow that exits the manifold, thermostat or any fitting for that matter, even the exhaust injection fitting.

Good luck chasing down the debris.

edit (shameless plug):
The basic alarm system with the flow sensor enhancement would have alerted you in an instant to the oversight. The EWDS would have alerted you AND told you what the problem was.

[sastanley]

shrek, to be sure you get them all, you need to recover the same number of vanes that you lost off the impeller...otherwise you won't know for sure if you got them all and some piece may lodge itself (again) down the road at the most inopportune time.

[Shrek]

Thanks

It seems that somebody up there may just love me. The exhaust seems to have spat out the blockage after some repeated start/stop cycles.
My flow from the exhaust outlet on the transom is as good as ever !
However I will heed both respondents advice regarding checking the obvious spots where things would lodge.

We flew down the Fraser River today on an ebb tide after replacing the impeller and apparently clearing the blockage (hopefully). Lots of black crud came out of the exhaust at the dock before we decided to go for it. The engine behaved well at 1800 rpm for 4.5 hours and as we entered our home base of Point Roberts, Washington State, USA, we throttled back to idle speed in gear approaching our slip. At this point the engine started to sound a little lumpy, stumbling a little bit too. Then, as we turned into our slip, it died, restarted it and it ran, but died again. We had a new jet fitted to the carb and had the carb cleaned out a few months ago, due to a blockage which was causing non starting. I am wondering why, when it idled at the dock for a long period of time prior to our 4+ hr. trip, why wouldn't it idle when hot, at the end of the trip? Performed well all the way throughout the trip. I guess the resistor is doing a good job for the coil as the coil was never too hot to touch !

Any ideas why it would stumble at low revs when hot ?

[hanleyclifford]

The idle system on the Zenith/Bendix carb is one of the most vulnerable to blockage on the carb. The tiny idle holes, one above and one below the throttle bore valve should be checked. Only the thinnest wire or a jeweler's drill bit can do this.

[ndutton]

The good news
A 4½ hour run without a repeat of the previous chronic coil failure routine is another Rule of 2011 success story. Welcome to the 100%, it's got to feel good.

The not so bad news
Your engine shut down at idle happened at the end of the 4½ hour run rather than the beginning or middle. Could have been worse.

The not so good news
What Hanley said. The carburetor's idle circuit needs cleaning and here is the operative word, AGAIN.

The bad news
Cleaning the carburetor addresses the symptom and not the cause. Krap in the carb is a problem but where it came from is the bigger problem. Unless you find and remedy the source you'll be doomed to repeated carburetor performance problems and repeated carburetor cleanings. Everything upstream of the carburetor is suspect. Time to inspect and analyze the entire fuel system from the fill plate to the engine. Good time to replace fuel hoses if it hasn't been done in a while.

[JOHN COOKSON]

#1 on getting clean fuel to the carburetor.

Did you try adjusting the idle mixture to see if it makes any difference?

Are you running to rich or to lean at idle? Here's how to tell. After the engine idles for a spell goose the throttle a bit in neutral. This will "unload" any richness in the cylinders and the idle will improve for a spell until the cylinders 'load"up again.

Here's a sort of far out one: The spark advance is sticky. At the initial idle the advance is not advanced and the idle is good. You run the engine at cruise RPM and when it is slowed down the advance stays advanced because it is sticky and the idle is rough.

TRUE GRIT

[Shrek]

It certainly does feel good !

As we cruised beyond the one hour mark I began to wonder if we finally had this coil issue solved. at 1.5 hours I had a little grin inside my head but was still afraid to show it as I did not want to jinx what might not be a totally smooth day on the water, due to the forecasted 20-25 knot winds which were to arrive slightly later in the day after our eta.
Let me explain my apprehensiveness in a little more detail. We start off in a major Canadian river with commercial traffic like car carrying ships going up and down, to or from the Far East, and large barges and tugs going about their business. Then we exit the river at a place called Sand Heads, which can be really ugly if you get it wrong (tides vs. winds = horrid big seas) Then we turn south along the sand flats and have to pass a major BC Ferries terminal, a coal port and all along the way we have these sand flats. There's nowhere to run to if we get in trouble. Yesterday, guess where the wind was coming from? Exactly where we were going, right on the nose, and we were not sailing we were deliberately motoring to prove out the resistor theory once and for all. After repairing the stupidly destroyed impeller in our raw water pump (we are fresh water cooled) we decided there was still enough ebb left to make a go of it and this was a good decision as we flew down the river doing about 7 knots and reduced to as little as 3 knots at times, even 2.5 when hitting larger swells coming right at us on the nose.
The only bummer was this idling issue as we neared our slip. We had the carb cleaned not too long ago in engine hours terms, and the main jet was cleaned out too. I will go over everything with the mechanic again and also install my brand new Moyer s/s sediment bowl, screen and bale, as well as install a secondary in line filter between the pump outlet and carb. What micron rating or brand would you folks suggest?

It was certainly a real smile on my face as we entered our home base after a 20 mile 4.5 hour journey and the coil temp was checked all the way and never so hot that you couldn't hold it for several seconds. I was a little surprised that the resistor wasn't as hot as expected either as I was always able to touch it with one finger and it was never any hotter than the coil.
Thanks to all of the folks who have helped me with these issues. Now that I am a little more relaxed, I will try to post some photographs from the last month, which will show the new rigging, and more importantly for some, the coil solution, and new buss bar which took the weight off the coil and organizes the ignition wiring much more tidily.
Photos to follow.

[Shrek]

Prop size/type

here is my original posting

I have a 1972 Columbia 30 which has an atomic 4 with a Walter V-drive and 2:1 ratio. Under the coil, the engine bears the stamp UJ-5 UF (The U and F are overlapped) as in my attached photo. My question is regarding my prop. It is a 15 x 9 RH prop and the C-30 owners manual called for a 16 x 9 RH prop. Does my prop have to work harder than a 16 x 9 prop to move the boat 9 inches forward, and result in more load on the engine trying to push the boat, or do I simply have less push from the prop?
I also believe my Canadian version of the A-4 to be limited to 15 hp. according to the model number.
My boat walks to port side in reverse and seems vey weak in reverse. Do I need to hold reverse firmly in place whilst backing up, as there is no detent position in reverse? or might I have slippage in reverse, or both ?
I ran all day yesterday at 1800 rpm mostly due to lack of confidence to push her any harder, following my coil problems, but could have probably gone up to wot at closer to 3000 rpm. In neutral she can turn at over 3000 but I never dare go there for more than an instant with a 44 year old motor. My factory manual calls for a 2 blade 16 x 9 RH prop and I have a 15 x 9 RH I also have a v-drive with 2:1 reduction. Would a 3 blade Indigo prop work for me or is that prop only for direct drive motors. Sastanley, are you looking at this ?
Any advice appreciated. BTW even in forward gear at idle speed she really goes well forwards !
GF

[Shrek]

New problem - there's always something !

Last weekend we motored perfectly for 4.5 hours following the pick up of about 3 gallons of new fuel (with ethanol)

On the way it was pretty choppy and we ran along perfectly.

On arrival inside the breakwater we puttered along towards the right turn into our finger of the marina, and as we neared the left turn into our slip I throttled back intending to engage reverse to slow us down a little. The A-4 spluttered to a halt and was difficult to start, but did so briefly before failing a second time as we neared the end of our slip and came to an abrupt but not damaging stop as we contacted the dock with the bow.

The mechanics determined water in the fuel sediment bowl and probably in the fuel tank.

We have since drained the tank as far as possible, the separating filter and the sediment bowl. Today we replaced the fuel with new fuel, 8 gallons 5 of which is premium and ethanol free gas. Started and ran right up to operating temp, then still would not idle. I am at my wits end ! HELP ! Only recent change is the new fuel and the recent addition of a 1.1 ohm resistor to save the coil - and it seems to be doing its job very well indeed !

Gordon.

[hanleyclifford]

One recent change is water in the fuel as determined by your mechanics. Also new is 4.5 hrs motoring in choppy conditions. That is bound to stir crud up in the tank. Now you don't have idle. The bet now is that the two small holes in the throttle bore, one above and one below, are plugged.