New to the forum, you'll probably hear from me a lot

[DiamondDealer]

Hello all. Name's Bill and I'm recently associated with an Ericson 39 that was powered by an Atomic 4. By associated I mean that a good friend and a family member just acquired the boat and I'm working with them by dint of my being an old sailor and former liveaboard.

We went to motor from her launch point to the new slip, around 8 or so hours by the waterways we had to take, and somewhere around an hour into the adventure the A4 gave up the ghost. Sudden complete loss of power and a puff of smoke.

The owner's first thought was to repower with a diesel, but financial reality rears its ugly head. My thought is to dig into the engine and see exactly what happened. Could we be lucky enough that it's just the head gasket? Rings maybe? This is apparently the original 1970 engine that's been "rebuilt" a few times over the decades. I could well be too optimistic.

My credentials for this are so-so, I'll admit. I had antique gasoline tractors that seem very similar, and I've done more than a little work on cars and my motorcycles over the years. Not a mechanic, but a capable wrencher. I can follow instructions.

Any help you might be able to throw my way over the next few months will be much appreciated. I'm really happy to have found the forum.

[Peter]

diagnostics

Dealer,

Sudden complete loss of power sounds like an electrical problem to me - loss of spark.

Have you checked for spark?

Caution notes

1) do not do a lot of cranking of the engine with the cooling water intake thru-hull open if you have a water lift muffler
2) do not leave the ignition on for prolonged periods while testing - risk of damage to the coil

Hope that helps,

Peter

[nyvoyager]

Air, spark and fuel.
I'd start with spark

[Dave Neptune]

DiamondDealer, first welcome to the MMI Afourian Forum.

Your description does not give any info of what has been checked or what is still working. Can you give us any idea of what has been checked? This will lead us to a logical diagnostic procedure.

Or describe what it does if you try to start now after the "puff".

Dave Neptune

[Antibes]

Most of the time the motor itself is fine, that's why everyone is asking questions. You should be more qualified than a lot of us when we started with our A4s if you worked with tractor motors

[DiamondDealer]

Thanks very much for the suggestions, everyone. I'm hoping to get out there this week to begin figuring this out.

I didn't describe what actually happened very well. We were motoring with the tide and doing pretty well when the tone of the engine changed slightly. Within moments we could make absolutely no way at all, though the engine continued to run. At first I thought maybe we'd somehow spun the prop off because of the lack of control. We had a friend in a small motorboat putting around us who said he saw smoke pour out of the exhaust at the same time. I didn't see any smoke at all from my place at the helm, which I take as a good thing. At least the entire engine didn't blow up! Naturally I killed the engine as soon as I realized there was a problem. Couldn't have been more than 5 or so seconds after whatever happened happened, if that.

We had her towed to her slip where the only thing we've been able to check is that the prop actually is still in place. It's a 2 blade folder that really isn't appropriate for the currents / tides we get in our coastal waters, so we intend to change it out anyway.

So that's pretty much it so far. I'll do all the typical initial stuff when I get down there later in the week (I hope). My post was probably a little premature, but I thought it'd be a good idea to introduce myself and our situation so you'll know why I'm bugging the heck outta you later!

[Dave Neptune]

DD, when you start checking first shut off the water intake valve. Give the engine a quick spin on the starter to confirm "rotation".

Pull the plugs and line them up in order for a "read" and post a pic. The plugs may just tell the story.

When the engine was acting up did you loose RPM's? Could be a simple case of intermittent valve sticking.

Now if the engine rotates and the plugs are out do a dry compression check first and record the values. Them spray some oil into the cylinder to do a wet compression check on each cylinder and record. This will give a good deal of info.

If the waters and conditions when the engine acted up were much rougher than the boat is usually out in it may be as simple as some KRUD being sucked into the fuel.

Get some info.

Dave Neptune

[Sam]

Well, your going to get some great advice here and good diagnostics. Just based on my experience only of "not making headway and the engine continuing to run...thought we might have lost the prop"etc my GUESS is your "slipping " out of forward ie in your reversing gearbox "trans". You have an adjusting collar, pressure plate fingers on the detent grove etc. the smoke could be "steam" or exhaust at higher rpm?

The possible solution here is to remove the cover, look and try the shifting lever and see if all is working as it should. Read up on past threads and the Moyer manual for making the adjustment if needed. Again, I am not recommending skipping the diagnostics because the problem could be elsewhere. It's just me possibly zeroing in based on a similar described past experience.